Normalize JPEG color conversion SIMD

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.CmykOperator.cs

@@ -0,0 +1,245 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    /// <summary>
+    /// Implements inverted JPEG CMYK conversion for scalar and SIMD lanes.
+    /// </summary>
+    internal readonly struct CmykOperator : IJpegColorConverterOperator
+    {
+        /// <inheritdoc/>
+        public static JpegColorSpace ColorSpace => JpegColorSpace.Cmyk;
+
+        /// <inheritdoc/>
+        public static int ComponentCount => 4;
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref float c0,
+            ref float c1,
+            ref float c2,
+            float c3,
+            float maximumValue,
+            float halfValue,
+            float scale)
+        {
+            // Adobe-style CMYK stores inverted component samples. Multiplying K by scale twice folds the
+            // two sample-domain divisions into one factor before it modulates the C, M, and Y planes.
+            float scaledK = c3 * scale * scale;
+            c0 *= scaledK;
+            c1 *= scaledK;
+            c2 *= scaledK;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector128<float> c0,
+            ref Vector128<float> c1,
+            ref Vector128<float> c2,
+            Vector128<float> c3,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale)
+        {
+            // Each K lane supplies the common modulation factor for the corresponding C, M, and Y lanes.
+            Vector128<float> scaledK = c3 * scale * scale;
+            c0 *= scaledK;
+            c1 *= scaledK;
+            c2 *= scaledK;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector256<float> c0,
+            ref Vector256<float> c1,
+            ref Vector256<float> c2,
+            Vector256<float> c3,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale)
+        {
+            // Eight independent CMYK samples remain lane-aligned throughout the modulation.
+            Vector256<float> scaledK = c3 * scale * scale;
+            c0 *= scaledK;
+            c1 *= scaledK;
+            c2 *= scaledK;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector512<float> c0,
+            ref Vector512<float> c1,
+            ref Vector512<float> c2,
+            Vector512<float> c3,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale)
+        {
+            // Sixteen independent CMYK samples remain lane-aligned throughout the modulation.
+            Vector512<float> scaledK = c3 * scale * scale;
+            c0 *= scaledK;
+            c1 *= scaledK;
+            c2 *= scaledK;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            float r,
+            float g,
+            float b,
+            float maximumValue,
+            float halfValue,
+            float scale,
+            out float c0,
+            out float c1,
+            out float c2,
+            out float c3)
+        {
+            float c = maximumValue - r;
+            float m = maximumValue - g;
+            float y = maximumValue - b;
+            float k = MathF.Min(c, MathF.Min(m, y));
+
+            // Pure black makes the chromatic divisor zero. In that case chromatic ink is defined as zero;
+            // otherwise remove K and normalize the remaining C, M, and Y contributions.
+            if (k >= maximumValue)
+            {
+                c = 0;
+                m = 0;
+                y = 0;
+            }
+            else
+            {
+                // The same remaining range normalizes every chromatic channel. Computing its reciprocal once
+                // replaces three divisions with one division and three multiplies.
+                float reciprocal = 1F / (maximumValue - k);
+                c = (c - k) * reciprocal;
+                m = (m - k) * reciprocal;
+                y = (y - k) * reciprocal;
+            }
+
+            // JPEG CMYK is inverted, including K, so normalized chromatic values are reflected around max.
+            c0 = maximumValue - (c * maximumValue);
+            c1 = maximumValue - (m * maximumValue);
+            c2 = maximumValue - (y * maximumValue);
+            c3 = maximumValue - k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector128<float> r,
+            Vector128<float> g,
+            Vector128<float> b,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale,
+            out Vector128<float> c0,
+            out Vector128<float> c1,
+            out Vector128<float> c2,
+            out Vector128<float> c3)
+        {
+            Vector128<float> c = maximumValue - r;
+            Vector128<float> m = maximumValue - g;
+            Vector128<float> y = maximumValue - b;
+            Vector128<float> k = Vector128.Min(c, Vector128.Min(m, y));
+
+            // The all-bits mask clears the undefined zero-divisor result for pure-black lanes without a branch.
+            Vector128<float> nonBlack = ~Vector128.Equals(k, maximumValue);
+            Vector128<float> reciprocal = Vector128<float>.One / (maximumValue - k);
+            c = ((c - k) * reciprocal) & nonBlack;
+            m = ((m - k) * reciprocal) & nonBlack;
+            y = ((y - k) * reciprocal) & nonBlack;
+
+            c0 = maximumValue - (c * maximumValue);
+            c1 = maximumValue - (m * maximumValue);
+            c2 = maximumValue - (y * maximumValue);
+            c3 = maximumValue - k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector256<float> r,
+            Vector256<float> g,
+            Vector256<float> b,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale,
+            out Vector256<float> c0,
+            out Vector256<float> c1,
+            out Vector256<float> c2,
+            out Vector256<float> c3)
+        {
+            Vector256<float> c = maximumValue - r;
+            Vector256<float> m = maximumValue - g;
+            Vector256<float> y = maximumValue - b;
+            Vector256<float> k = Vector256.Min(c, Vector256.Min(m, y));
+
+            // Masking preserves lane independence when a vector mixes pure black with chromatic pixels.
+            Vector256<float> nonBlack = ~Vector256.Equals(k, maximumValue);
+            Vector256<float> reciprocal = Vector256<float>.One / (maximumValue - k);
+            c = ((c - k) * reciprocal) & nonBlack;
+            m = ((m - k) * reciprocal) & nonBlack;
+            y = ((y - k) * reciprocal) & nonBlack;
+
+            c0 = maximumValue - (c * maximumValue);
+            c1 = maximumValue - (m * maximumValue);
+            c2 = maximumValue - (y * maximumValue);
+            c3 = maximumValue - k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector512<float> r,
+            Vector512<float> g,
+            Vector512<float> b,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale,
+            out Vector512<float> c0,
+            out Vector512<float> c1,
+            out Vector512<float> c2,
+            out Vector512<float> c3)
+        {
+            Vector512<float> c = maximumValue - r;
+            Vector512<float> m = maximumValue - g;
+            Vector512<float> y = maximumValue - b;
+            Vector512<float> k = Vector512.Min(c, Vector512.Min(m, y));
+
+            // AVX-512 still uses a full floating-point mask value here because bitwise clearing exactly matches
+            // the narrower operator semantics and lets the JIT select the most suitable native instructions.
+            Vector512<float> nonBlack = ~Vector512.Equals(k, maximumValue);
+            Vector512<float> reciprocal = Vector512<float>.One / (maximumValue - k);
+            c = ((c - k) * reciprocal) & nonBlack;
+            m = ((m - k) * reciprocal) & nonBlack;
+            y = ((y - k) * reciprocal) & nonBlack;
+
+            c0 = maximumValue - (c * maximumValue);
+            c1 = maximumValue - (m * maximumValue);
+            c2 = maximumValue - (y * maximumValue);
+            c3 = maximumValue - k;
+        }
+
+        /// <inheritdoc/>
+        public static void ConvertToRgbInPlaceWithIcc(
+            Configuration configuration,
+            IccProfile profile,
+            in ComponentValues values,
+            float maximumValue)
+            => CmykScalar.ConvertToRgbInPlaceWithIcc(configuration, profile, values, maximumValue);
+    }
+}

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.GrayScaleOperator.cs

@@ -0,0 +1,203 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.Common.Helpers;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    /// <summary>
+    /// Implements grayscale expansion and RGB luminance reduction for scalar and SIMD lanes.
+    /// </summary>
+    internal readonly struct GrayScaleOperator : IJpegColorConverterOperator
+    {
+        /// <inheritdoc/>
+        public static JpegColorSpace ColorSpace => JpegColorSpace.Grayscale;
+
+        /// <inheritdoc/>
+        public static int ComponentCount => 1;
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref float c0,
+            ref float c1,
+            ref float c2,
+            float c3,
+            float maximumValue,
+            float halfValue,
+            float scale)
+        {
+            // JPEG stores luminance in the integer sample domain. Normalize it once, then duplicate the
+            // same value into all three RGB planes. Keeping it local also prevents potentially aliasing
+            // byref stores from forcing the JIT to reload c0 between assignments.
+            float luminance = c0 * scale;
+            c0 = luminance;
+            c1 = luminance;
+            c2 = luminance;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector128<float> c0,
+            ref Vector128<float> c1,
+            ref Vector128<float> c2,
+            Vector128<float> c3,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale)
+        {
+            // Each XMM lane is one independent luminance sample. Reusing the normalized vector for R, G,
+            // and B avoids recomputing the scale and keeps it live across potentially aliasing byref stores.
+            Vector128<float> luminance = c0 * scale;
+            c0 = luminance;
+            c1 = luminance;
+            c2 = luminance;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector256<float> c0,
+            ref Vector256<float> c1,
+            ref Vector256<float> c2,
+            Vector256<float> c3,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale)
+        {
+            // Eight luminance samples occupy the YMM lanes. The local retains the normalized vector across
+            // all three output stores even when the destination planes alias.
+            Vector256<float> luminance = c0 * scale;
+            c0 = luminance;
+            c1 = luminance;
+            c2 = luminance;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector512<float> c0,
+            ref Vector512<float> c1,
+            ref Vector512<float> c2,
+            Vector512<float> c3,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale)
+        {
+            // Sixteen luminance samples occupy the ZMM lanes. The local retains the normalized vector across
+            // all three output stores without shuffles, interleaving, or source reloads.
+            Vector512<float> luminance = c0 * scale;
+            c0 = luminance;
+            c1 = luminance;
+            c2 = luminance;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            float r,
+            float g,
+            float b,
+            float maximumValue,
+            float halfValue,
+            float scale,
+            out float c0,
+            out float c1,
+            out float c2,
+            out float c3)
+        {
+            // Rec.601 luma weights operate directly in the encoder sample domain. Only c0 is stored for a
+            // one-component model; the remaining out values exist solely to satisfy the common operator shape.
+            c0 = (0.299F * r) + (0.587F * g) + (0.114F * b);
+            c1 = 0;
+            c2 = 0;
+            c3 = 0;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector128<float> r,
+            Vector128<float> g,
+            Vector128<float> b,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale,
+            out Vector128<float> c0,
+            out Vector128<float> c1,
+            out Vector128<float> c2,
+            out Vector128<float> c3)
+        {
+            // The nested estimate gives each pixel the same multiply-add grouping as the scalar Rec.601 formula.
+            c0 = Vector128_.MultiplyAddEstimate(
+                Vector128.Create(0.299F),
+                r,
+                Vector128_.MultiplyAddEstimate(Vector128.Create(0.587F), g, Vector128.Create(0.114F) * b));
+            c1 = default;
+            c2 = default;
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector256<float> r,
+            Vector256<float> g,
+            Vector256<float> b,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale,
+            out Vector256<float> c0,
+            out Vector256<float> c1,
+            out Vector256<float> c2,
+            out Vector256<float> c3)
+        {
+            // YMM lanes evaluate the same Rec.601 equation independently, with no horizontal lane reduction.
+            c0 = Vector256_.MultiplyAddEstimate(
+                Vector256.Create(0.299F),
+                r,
+                Vector256_.MultiplyAddEstimate(Vector256.Create(0.587F), g, Vector256.Create(0.114F) * b));
+            c1 = default;
+            c2 = default;
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector512<float> r,
+            Vector512<float> g,
+            Vector512<float> b,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale,
+            out Vector512<float> c0,
+            out Vector512<float> c1,
+            out Vector512<float> c2,
+            out Vector512<float> c3)
+        {
+            // ZMM lanes retain the same arithmetic order as narrower paths so only SIMD width changes.
+            c0 = Vector512_.MultiplyAddEstimate(
+                Vector512.Create(0.299F),
+                r,
+                Vector512_.MultiplyAddEstimate(Vector512.Create(0.587F), g, Vector512.Create(0.114F) * b));
+            c1 = default;
+            c2 = default;
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        public static void ConvertToRgbInPlaceWithIcc(
+            Configuration configuration,
+            IccProfile profile,
+            in ComponentValues values,
+            float maximumValue)
+            => GrayScaleScalar.ConvertToRgbInPlaceWithIcc(configuration, profile, values, maximumValue);
+    }
+}

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.Operator.cs

@@ -0,0 +1,594 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.Common.Helpers;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    /// <summary>
+    /// Defines the color-model-specific arithmetic used by <see cref="JpegColorConverter{TOperator}"/>.
+    /// </summary>
+    /// <remarks>
+    /// Each overload describes the same lane-wise transform. The generic traversal selects the widest
+    /// available overload and the JIT resolves these static interface calls for each closed converter type.
+    /// </remarks>
+    internal interface IJpegColorConverterOperator
+    {
+        /// <summary>
+        /// Gets the JPEG color space handled by the operator.
+        /// </summary>
+        static abstract JpegColorSpace ColorSpace { get; }
+
+        /// <summary>
+        /// Gets the number of component planes used by the color space.
+        /// </summary>
+        static abstract int ComponentCount { get; }
+
+        /// <summary>
+        /// Converts one JPEG sample to normalized RGB.
+        /// </summary>
+        /// <param name="c0">The first component, replaced by red.</param>
+        /// <param name="c1">The second component, replaced by green.</param>
+        /// <param name="c2">The third component, replaced by blue.</param>
+        /// <param name="c3">The fourth component, or zero for a three-component color space.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        /// <param name="halfValue">The midpoint component value for the configured precision.</param>
+        /// <param name="scale">The reciprocal of <paramref name="maximumValue"/>.</param>
+        static abstract void ConvertToRgb(
+            ref float c0,
+            ref float c1,
+            ref float c2,
+            float c3,
+            float maximumValue,
+            float halfValue,
+            float scale);
+
+        /// <summary>
+        /// Converts four JPEG samples to normalized RGB.
+        /// </summary>
+        /// <param name="c0">The first component lanes, replaced by red.</param>
+        /// <param name="c1">The second component lanes, replaced by green.</param>
+        /// <param name="c2">The third component lanes, replaced by blue.</param>
+        /// <param name="c3">The fourth component lanes, or zero for a three-component color space.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        /// <param name="halfValue">The midpoint component value for the configured precision.</param>
+        /// <param name="scale">The reciprocal of <paramref name="maximumValue"/> in every lane.</param>
+        static abstract void ConvertToRgb(
+            ref Vector128<float> c0,
+            ref Vector128<float> c1,
+            ref Vector128<float> c2,
+            Vector128<float> c3,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale);
+
+        /// <summary>
+        /// Converts eight JPEG samples to normalized RGB.
+        /// </summary>
+        /// <param name="c0">The first component lanes, replaced by red.</param>
+        /// <param name="c1">The second component lanes, replaced by green.</param>
+        /// <param name="c2">The third component lanes, replaced by blue.</param>
+        /// <param name="c3">The fourth component lanes, or zero for a three-component color space.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        /// <param name="halfValue">The midpoint component value for the configured precision.</param>
+        /// <param name="scale">The reciprocal of <paramref name="maximumValue"/> in every lane.</param>
+        static abstract void ConvertToRgb(
+            ref Vector256<float> c0,
+            ref Vector256<float> c1,
+            ref Vector256<float> c2,
+            Vector256<float> c3,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale);
+
+        /// <summary>
+        /// Converts sixteen JPEG samples to normalized RGB.
+        /// </summary>
+        /// <param name="c0">The first component lanes, replaced by red.</param>
+        /// <param name="c1">The second component lanes, replaced by green.</param>
+        /// <param name="c2">The third component lanes, replaced by blue.</param>
+        /// <param name="c3">The fourth component lanes, or zero for a three-component color space.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        /// <param name="halfValue">The midpoint component value for the configured precision.</param>
+        /// <param name="scale">The reciprocal of <paramref name="maximumValue"/> in every lane.</param>
+        static abstract void ConvertToRgb(
+            ref Vector512<float> c0,
+            ref Vector512<float> c1,
+            ref Vector512<float> c2,
+            Vector512<float> c3,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale);
+
+        /// <summary>
+        /// Converts one RGB sample to JPEG components.
+        /// </summary>
+        /// <param name="r">The red value.</param>
+        /// <param name="g">The green value.</param>
+        /// <param name="b">The blue value.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        /// <param name="halfValue">The midpoint component value for the configured precision.</param>
+        /// <param name="scale">The reciprocal of <paramref name="maximumValue"/>.</param>
+        /// <param name="c0">The first converted component.</param>
+        /// <param name="c1">The second converted component.</param>
+        /// <param name="c2">The third converted component.</param>
+        /// <param name="c3">The fourth converted component, if used.</param>
+        static abstract void ConvertFromRgb(
+            float r,
+            float g,
+            float b,
+            float maximumValue,
+            float halfValue,
+            float scale,
+            out float c0,
+            out float c1,
+            out float c2,
+            out float c3);
+
+        /// <summary>
+        /// Converts four RGB samples to JPEG components.
+        /// </summary>
+        /// <param name="r">The red lanes.</param>
+        /// <param name="g">The green lanes.</param>
+        /// <param name="b">The blue lanes.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        /// <param name="halfValue">The midpoint component value for the configured precision.</param>
+        /// <param name="scale">The reciprocal of <paramref name="maximumValue"/> in every lane.</param>
+        /// <param name="c0">The first converted component lanes.</param>
+        /// <param name="c1">The second converted component lanes.</param>
+        /// <param name="c2">The third converted component lanes.</param>
+        /// <param name="c3">The fourth converted component lanes, if used.</param>
+        static abstract void ConvertFromRgb(
+            Vector128<float> r,
+            Vector128<float> g,
+            Vector128<float> b,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale,
+            out Vector128<float> c0,
+            out Vector128<float> c1,
+            out Vector128<float> c2,
+            out Vector128<float> c3);
+
+        /// <summary>
+        /// Converts eight RGB samples to JPEG components.
+        /// </summary>
+        /// <param name="r">The red lanes.</param>
+        /// <param name="g">The green lanes.</param>
+        /// <param name="b">The blue lanes.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        /// <param name="halfValue">The midpoint component value for the configured precision.</param>
+        /// <param name="scale">The reciprocal of <paramref name="maximumValue"/> in every lane.</param>
+        /// <param name="c0">The first converted component lanes.</param>
+        /// <param name="c1">The second converted component lanes.</param>
+        /// <param name="c2">The third converted component lanes.</param>
+        /// <param name="c3">The fourth converted component lanes, if used.</param>
+        static abstract void ConvertFromRgb(
+            Vector256<float> r,
+            Vector256<float> g,
+            Vector256<float> b,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale,
+            out Vector256<float> c0,
+            out Vector256<float> c1,
+            out Vector256<float> c2,
+            out Vector256<float> c3);
+
+        /// <summary>
+        /// Converts sixteen RGB samples to JPEG components.
+        /// </summary>
+        /// <param name="r">The red lanes.</param>
+        /// <param name="g">The green lanes.</param>
+        /// <param name="b">The blue lanes.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        /// <param name="halfValue">The midpoint component value for the configured precision.</param>
+        /// <param name="scale">The reciprocal of <paramref name="maximumValue"/> in every lane.</param>
+        /// <param name="c0">The first converted component lanes.</param>
+        /// <param name="c1">The second converted component lanes.</param>
+        /// <param name="c2">The third converted component lanes.</param>
+        /// <param name="c3">The fourth converted component lanes, if used.</param>
+        static abstract void ConvertFromRgb(
+            Vector512<float> r,
+            Vector512<float> g,
+            Vector512<float> b,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale,
+            out Vector512<float> c0,
+            out Vector512<float> c1,
+            out Vector512<float> c2,
+            out Vector512<float> c3);
+
+        /// <summary>
+        /// Converts JPEG component values to RGB using the supplied ICC profile.
+        /// </summary>
+        /// <param name="configuration">The configuration used to allocate temporary storage.</param>
+        /// <param name="profile">The source ICC profile.</param>
+        /// <param name="values">The component values to convert.</param>
+        /// <param name="maximumValue">The maximum component value for the configured precision.</param>
+        static abstract void ConvertToRgbInPlaceWithIcc(
+            Configuration configuration,
+            IccProfile profile,
+            in ComponentValues values,
+            float maximumValue);
+    }
+
+    /// <summary>
+    /// Converts a JPEG color model using a single operator-driven traversal for all SIMD widths.
+    /// </summary>
+    /// <typeparam name="TOperator">The color-model-specific arithmetic.</typeparam>
+    internal sealed class JpegColorConverter<TOperator> : JpegColorConverterBase
+        where TOperator : struct, IJpegColorConverterOperator
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="JpegColorConverter{TOperator}"/> class.
+        /// </summary>
+        /// <param name="precision">The precision in bits.</param>
+        public JpegColorConverter(int precision)
+            : base(TOperator.ColorSpace, precision)
+        {
+        }
+
+        /// <inheritdoc/>
+        public override bool IsAvailable => true;
+
+        /// <inheritdoc/>
+        public override int ElementsPerBatch
+            => Vector512.IsHardwareAccelerated
+                ? Vector512<float>.Count
+                : Vector256.IsHardwareAccelerated
+                    ? Vector256<float>.Count
+                    : Vector128.IsHardwareAccelerated
+                        ? Vector128<float>.Count
+                        : 1;
+
+        /// <inheritdoc/>
+        public override void ConvertToRgbInPlace(in ComponentValues values)
+        {
+            // JPEG component processors own equally sized planar buffers. Capturing their first elements
+            // as byrefs lets every width share the same offset without introducing Span bounds checks in
+            // the hot loops. Component3 may be empty; its byref is only dereferenced for four-component operators.
+            ref float c0Base = ref MemoryMarshal.GetReference(values.Component0);
+            ref float c1Base = ref MemoryMarshal.GetReference(values.Component1);
+            ref float c2Base = ref MemoryMarshal.GetReference(values.Component2);
+            ref float c3Base = ref MemoryMarshal.GetReference(values.Component3);
+
+            int length = values.Component0.Length;
+            int i = 0;
+            float scale = 1F / this.MaximumValue;
+
+            // Descending widths keep one traversal while allowing an AVX-512 machine to process
+            // an eight-pixel JPEG block with AVX2 rather than sending the entire block to scalar code.
+            if (Vector512.IsHardwareAccelerated)
+            {
+                // Subtracting the lane count turns the loop condition into a single signed comparison.
+                // A negative value naturally skips this width, and i <= end proves every unaligned
+                // 64-byte reinterpretation remains entirely inside its component buffer.
+                int oneVectorFromEnd = length - Vector512<float>.Count;
+
+                if (i <= oneVectorFromEnd)
+                {
+                    // Precision-derived values are broadcast only when this width has work. Keeping them outside
+                    // the loop avoids repeated setup without penalizing rows handled entirely by narrower widths.
+                    Vector512<float> maximumValue = Vector512.Create(this.MaximumValue);
+                    Vector512<float> halfValue = Vector512.Create(this.HalfValue);
+                    Vector512<float> scaleVector = Vector512.Create(scale);
+
+                    for (; i <= oneVectorFromEnd; i += Vector512<float>.Count)
+                    {
+                        ref Vector512<float> c0 = ref Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref c0Base, i));
+                        ref Vector512<float> c1 = ref Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref c1Base, i));
+                        ref Vector512<float> c2 = ref Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref c2Base, i));
+
+                        // ComponentCount is a static property on the closed operator type, so the JIT removes
+                        // this choice. Three-component models never dereference the empty Component3 byref.
+                        Vector512<float> c3 = TOperator.ComponentCount == 4
+                            ? Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref c3Base, i))
+                            : default;
+
+                        // c0-c2 alias the planar source vectors and are replaced in place with normalized RGB.
+                        // c3 is passed by value because the fourth JPEG component must remain unchanged.
+                        TOperator.ConvertToRgb(ref c0, ref c1, ref c2, c3, maximumValue, halfValue, scaleVector);
+                    }
+                }
+            }
+
+            if (Vector256.IsHardwareAccelerated)
+            {
+                // The shared offset continues where AVX-512 stopped. At this point fewer than sixteen
+                // samples remain, so this stage consumes the complete eight-sample remainder when present.
+                int oneVectorFromEnd = length - Vector256<float>.Count;
+
+                if (i <= oneVectorFromEnd)
+                {
+                    // YMM precision state is materialized only for an eight-sample remainder or an AVX2-only loop.
+                    Vector256<float> maximumValue = Vector256.Create(this.MaximumValue);
+                    Vector256<float> halfValue = Vector256.Create(this.HalfValue);
+                    Vector256<float> scaleVector = Vector256.Create(scale);
+
+                    for (; i <= oneVectorFromEnd; i += Vector256<float>.Count)
+                    {
+                        ref Vector256<float> c0 = ref Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref c0Base, i));
+                        ref Vector256<float> c1 = ref Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref c1Base, i));
+                        ref Vector256<float> c2 = ref Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref c2Base, i));
+
+                        // The closed operator makes this a compile-time color-model choice, not a per-vector
+                        // runtime abstraction or interface dispatch.
+                        Vector256<float> c3 = TOperator.ComponentCount == 4
+                            ? Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref c3Base, i))
+                            : default;
+
+                        TOperator.ConvertToRgb(ref c0, ref c1, ref c2, c3, maximumValue, halfValue, scaleVector);
+                    }
+                }
+            }
+
+            if (Vector128.IsHardwareAccelerated)
+            {
+                // SSE/AdvSimd handles the final four complete samples. This also gives non-AVX machines
+                // the same traversal without duplicating the control flow for another register width.
+                int oneVectorFromEnd = length - Vector128<float>.Count;
+
+                if (i <= oneVectorFromEnd)
+                {
+                    // XMM state is likewise created only when four samples remain for this stage.
+                    Vector128<float> maximumValue = Vector128.Create(this.MaximumValue);
+                    Vector128<float> halfValue = Vector128.Create(this.HalfValue);
+                    Vector128<float> scaleVector = Vector128.Create(scale);
+
+                    for (; i <= oneVectorFromEnd; i += Vector128<float>.Count)
+                    {
+                        ref Vector128<float> c0 = ref Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref c0Base, i));
+                        ref Vector128<float> c1 = ref Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref c1Base, i));
+                        ref Vector128<float> c2 = ref Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref c2Base, i));
+
+                        // As at the wider stages, the fourth vector is loaded only for CMYK-shaped operators.
+                        Vector128<float> c3 = TOperator.ComponentCount == 4
+                            ? Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref c3Base, i))
+                            : default;
+
+                        TOperator.ConvertToRgb(ref c0, ref c1, ref c2, c3, maximumValue, halfValue, scaleVector);
+                    }
+                }
+            }
+
+            // Fewer than four samples remain after the SIMD cascade. Processing from the shared offset
+            // guarantees each sample is visited exactly once for arbitrary test lengths and JPEG block rows.
+            for (; i < length; i++)
+            {
+                float c3 = TOperator.ComponentCount == 4 ? Unsafe.Add(ref c3Base, i) : 0;
+
+                TOperator.ConvertToRgb(
+                    ref Unsafe.Add(ref c0Base, i),
+                    ref Unsafe.Add(ref c1Base, i),
+                    ref Unsafe.Add(ref c2Base, i),
+                    c3,
+                    this.MaximumValue,
+                    this.HalfValue,
+                    scale);
+            }
+        }
+
+        /// <inheritdoc/>
+        public override void ConvertToRgbInPlaceWithIcc(Configuration configuration, in ComponentValues values, IccProfile profile)
+            => TOperator.ConvertToRgbInPlaceWithIcc(configuration, profile, values, this.MaximumValue);
+
+        /// <inheritdoc/>
+        public override void ConvertFromRgb(in ComponentValues values, Span<float> rLane, Span<float> gLane, Span<float> bLane)
+        {
+            // The encoder supplies equally sized RGB planes and destination component planes. Byrefs preserve
+            // contiguous access and allow the same proven vector boundary to govern every participating lane.
+            // Component3 is empty for three-component formats and is only written by four-component operators.
+            ref float c0Base = ref MemoryMarshal.GetReference(values.Component0);
+            ref float c1Base = ref MemoryMarshal.GetReference(values.Component1);
+            ref float c2Base = ref MemoryMarshal.GetReference(values.Component2);
+            ref float c3Base = ref MemoryMarshal.GetReference(values.Component3);
+            ref float rBase = ref MemoryMarshal.GetReference(rLane);
+            ref float gBase = ref MemoryMarshal.GetReference(gLane);
+            ref float bBase = ref MemoryMarshal.GetReference(bLane);
+
+            int length = values.Component0.Length;
+            int i = 0;
+            float scale = 1F / this.MaximumValue;
+
+            // Each vector overload returns planar component vectors. Storing them here keeps the
+            // operator concerned only with color arithmetic and preserves contiguous lane access.
+            if (Vector512.IsHardwareAccelerated)
+            {
+                // The end offset proves all three 64-byte RGB reads and all component writes are in range.
+                // A short row yields a negative end and falls through to the next supported width.
+                int oneVectorFromEnd = length - Vector512<float>.Count;
+
+                if (i <= oneVectorFromEnd)
+                {
+                    // Operators receive width-matched precision state only when this width has work, keeping
+                    // invariant broadcasts outside the loop without charging narrower or scalar rows for them.
+                    Vector512<float> maximumValue = Vector512.Create(this.MaximumValue);
+                    Vector512<float> halfValue = Vector512.Create(this.HalfValue);
+                    Vector512<float> scaleVector = Vector512.Create(scale);
+
+                    for (; i <= oneVectorFromEnd; i += Vector512<float>.Count)
+                    {
+                        Vector512<float> r = Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref rBase, i));
+                        Vector512<float> g = Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref gBase, i));
+                        Vector512<float> b = Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref bBase, i));
+
+                        TOperator.ConvertFromRgb(
+                            r,
+                            g,
+                            b,
+                            maximumValue,
+                            halfValue,
+                            scaleVector,
+                            out Vector512<float> c0,
+                            out Vector512<float> c1,
+                            out Vector512<float> c2,
+                            out Vector512<float> c3);
+
+                        // Outputs remain planar: each vector contains sixteen consecutive samples from one
+                        // JPEG component. Static count checks prevent grayscale from touching absent planes
+                        // while disappearing completely from three- and four-component specializations.
+                        Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref c0Base, i)) = c0;
+
+                        if (TOperator.ComponentCount >= 2)
+                        {
+                            Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref c1Base, i)) = c1;
+                        }
+
+                        if (TOperator.ComponentCount >= 3)
+                        {
+                            Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref c2Base, i)) = c2;
+                        }
+
+                        if (TOperator.ComponentCount >= 4)
+                        {
+                            Unsafe.As<float, Vector512<float>>(ref Unsafe.Add(ref c3Base, i)) = c3;
+                        }
+                    }
+                }
+            }
+
+            if (Vector256.IsHardwareAccelerated)
+            {
+                // Continue from the AVX-512 offset so an eight-sample tail stays vectorized on AVX-512 CPUs.
+                int oneVectorFromEnd = length - Vector256<float>.Count;
+
+                if (i <= oneVectorFromEnd)
+                {
+                    // Materialize YMM state only for an eight-sample remainder or an AVX2-only loop.
+                    Vector256<float> maximumValue = Vector256.Create(this.MaximumValue);
+                    Vector256<float> halfValue = Vector256.Create(this.HalfValue);
+                    Vector256<float> scaleVector = Vector256.Create(scale);
+
+                    for (; i <= oneVectorFromEnd; i += Vector256<float>.Count)
+                    {
+                        Vector256<float> r = Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref rBase, i));
+                        Vector256<float> g = Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref gBase, i));
+                        Vector256<float> b = Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref bBase, i));
+
+                        TOperator.ConvertFromRgb(
+                            r,
+                            g,
+                            b,
+                            maximumValue,
+                            halfValue,
+                            scaleVector,
+                            out Vector256<float> c0,
+                            out Vector256<float> c1,
+                            out Vector256<float> c2,
+                            out Vector256<float> c3);
+
+                        // Static count checks write only planes owned by this color model.
+                        Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref c0Base, i)) = c0;
+
+                        if (TOperator.ComponentCount >= 2)
+                        {
+                            Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref c1Base, i)) = c1;
+                        }
+
+                        if (TOperator.ComponentCount >= 3)
+                        {
+                            Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref c2Base, i)) = c2;
+                        }
+
+                        if (TOperator.ComponentCount >= 4)
+                        {
+                            Unsafe.As<float, Vector256<float>>(ref Unsafe.Add(ref c3Base, i)) = c3;
+                        }
+                    }
+                }
+            }
+
+            if (Vector128.IsHardwareAccelerated)
+            {
+                // The final SIMD stage consumes four complete RGB samples on SSE or AdvSimd hardware.
+                int oneVectorFromEnd = length - Vector128<float>.Count;
+
+                if (i <= oneVectorFromEnd)
+                {
+                    // Materialize XMM state only when the final SIMD stage can consume four samples.
+                    Vector128<float> maximumValue = Vector128.Create(this.MaximumValue);
+                    Vector128<float> halfValue = Vector128.Create(this.HalfValue);
+                    Vector128<float> scaleVector = Vector128.Create(scale);
+
+                    for (; i <= oneVectorFromEnd; i += Vector128<float>.Count)
+                    {
+                        Vector128<float> r = Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref rBase, i));
+                        Vector128<float> g = Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref gBase, i));
+                        Vector128<float> b = Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref bBase, i));
+
+                        TOperator.ConvertFromRgb(
+                            r,
+                            g,
+                            b,
+                            maximumValue,
+                            halfValue,
+                            scaleVector,
+                            out Vector128<float> c0,
+                            out Vector128<float> c1,
+                            out Vector128<float> c2,
+                            out Vector128<float> c3);
+
+                        // Four results are stored only for the planes represented by the closed operator.
+                        Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref c0Base, i)) = c0;
+
+                        if (TOperator.ComponentCount >= 2)
+                        {
+                            Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref c1Base, i)) = c1;
+                        }
+
+                        if (TOperator.ComponentCount >= 3)
+                        {
+                            Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref c2Base, i)) = c2;
+                        }
+
+                        if (TOperator.ComponentCount >= 4)
+                        {
+                            Unsafe.As<float, Vector128<float>>(ref Unsafe.Add(ref c3Base, i)) = c3;
+                        }
+                    }
+                }
+            }
+
+            // Scalar conversion is reserved for the zero-to-three samples that cannot fill Vector128.
+            for (; i < length; i++)
+            {
+                TOperator.ConvertFromRgb(
+                    Unsafe.Add(ref rBase, i),
+                    Unsafe.Add(ref gBase, i),
+                    Unsafe.Add(ref bBase, i),
+                    this.MaximumValue,
+                    this.HalfValue,
+                    scale,
+                    out float c0,
+                    out float c1,
+                    out float c2,
+                    out float c3);
+
+                Unsafe.Add(ref c0Base, i) = c0;
+
+                if (TOperator.ComponentCount >= 2)
+                {
+                    Unsafe.Add(ref c1Base, i) = c1;
+                }
+
+                if (TOperator.ComponentCount >= 3)
+                {
+                    Unsafe.Add(ref c2Base, i) = c2;
+                }
+
+                if (TOperator.ComponentCount >= 4)
+                {
+                    Unsafe.Add(ref c3Base, i) = c3;
+                }
+            }
+        }
+    }
+}

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.RgbOperator.cs

@@ -0,0 +1,184 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    /// <summary>
+    /// Implements direct JPEG RGB normalization and planar RGB copying for scalar and SIMD lanes.
+    /// </summary>
+    internal readonly struct RgbOperator : IJpegColorConverterOperator
+    {
+        /// <inheritdoc/>
+        public static JpegColorSpace ColorSpace => JpegColorSpace.RGB;
+
+        /// <inheritdoc/>
+        public static int ComponentCount => 3;
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref float c0,
+            ref float c1,
+            ref float c2,
+            float c3,
+            float maximumValue,
+            float halfValue,
+            float scale)
+        {
+            // The JPEG planes already represent R, G, and B. Conversion therefore consists only of moving
+            // each integer-domain sample into the normalized floating-point domain consumed by pixel packing.
+            c0 *= scale;
+            c1 *= scale;
+            c2 *= scale;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector128<float> c0,
+            ref Vector128<float> c1,
+            ref Vector128<float> c2,
+            Vector128<float> c3,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale)
+        {
+            // Four samples from each planar channel remain in their lanes while sharing one normalization vector.
+            c0 *= scale;
+            c1 *= scale;
+            c2 *= scale;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector256<float> c0,
+            ref Vector256<float> c1,
+            ref Vector256<float> c2,
+            Vector256<float> c3,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale)
+        {
+            // Eight samples per plane are normalized independently without channel shuffles.
+            c0 *= scale;
+            c1 *= scale;
+            c2 *= scale;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector512<float> c0,
+            ref Vector512<float> c1,
+            ref Vector512<float> c2,
+            Vector512<float> c3,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale)
+        {
+            // Sixteen samples per plane are normalized independently without changing planar ordering.
+            c0 *= scale;
+            c1 *= scale;
+            c2 *= scale;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            float r,
+            float g,
+            float b,
+            float maximumValue,
+            float halfValue,
+            float scale,
+            out float c0,
+            out float c1,
+            out float c2,
+            out float c3)
+        {
+            // Encoder RGB lanes already use the JPEG sample domain, so the direct color model copies them.
+            c0 = r;
+            c1 = g;
+            c2 = b;
+            c3 = 0;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector128<float> r,
+            Vector128<float> g,
+            Vector128<float> b,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale,
+            out Vector128<float> c0,
+            out Vector128<float> c1,
+            out Vector128<float> c2,
+            out Vector128<float> c3)
+        {
+            // The planar vectors map one-to-one to JPEG components; the fourth result is statically discarded.
+            c0 = r;
+            c1 = g;
+            c2 = b;
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector256<float> r,
+            Vector256<float> g,
+            Vector256<float> b,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale,
+            out Vector256<float> c0,
+            out Vector256<float> c1,
+            out Vector256<float> c2,
+            out Vector256<float> c3)
+        {
+            // The planar vectors map one-to-one to JPEG components; no arithmetic or rearrangement is required.
+            c0 = r;
+            c1 = g;
+            c2 = b;
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector512<float> r,
+            Vector512<float> g,
+            Vector512<float> b,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale,
+            out Vector512<float> c0,
+            out Vector512<float> c1,
+            out Vector512<float> c2,
+            out Vector512<float> c3)
+        {
+            // The widest path is likewise a register-to-register planar copy for sixteen pixels.
+            c0 = r;
+            c1 = g;
+            c2 = b;
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        public static void ConvertToRgbInPlaceWithIcc(
+            Configuration configuration,
+            IccProfile profile,
+            in ComponentValues values,
+            float maximumValue)
+            => RgbScalar.ConvertToRgbInPlaceWithIcc(configuration, profile, values, maximumValue);
+    }
+}

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.TiffCmykOperator.cs

@@ -0,0 +1,159 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    /// <summary>
+    /// Implements non-inverted TIFF JPEG CMYK conversion for scalar and SIMD lanes.
+    /// </summary>
+    internal readonly struct TiffCmykOperator : IJpegColorConverterOperator
+    {
+        /// <inheritdoc/>
+        public static JpegColorSpace ColorSpace => JpegColorSpace.TiffCmyk;
+
+        /// <inheritdoc/>
+        public static int ComponentCount => 4;
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref float c0, ref float c1, ref float c2, float c3, float maximumValue, float halfValue, float scale)
+        {
+            // TIFF stores conventional CMYK rather than Adobe's inverted representation. Normalize every
+            // component, invert C/M/Y, and let the remaining light after K modulate each RGB channel.
+            float k = 1F - (c3 * scale);
+            c0 = (1F - (c0 * scale)) * k;
+            c1 = (1F - (c1 * scale)) * k;
+            c2 = (1F - (c2 * scale)) * k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector128<float> c0, ref Vector128<float> c1, ref Vector128<float> c2, Vector128<float> c3, Vector128<float> maximumValue, Vector128<float> halfValue, Vector128<float> scale)
+        {
+            // K remains lane-aligned with its C/M/Y sample while one-minus performs the non-inverted CMYK mapping.
+            Vector128<float> k = Vector128<float>.One - (c3 * scale);
+            c0 = (Vector128<float>.One - (c0 * scale)) * k;
+            c1 = (Vector128<float>.One - (c1 * scale)) * k;
+            c2 = (Vector128<float>.One - (c2 * scale)) * k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector256<float> c0, ref Vector256<float> c1, ref Vector256<float> c2, Vector256<float> c3, Vector256<float> maximumValue, Vector256<float> halfValue, Vector256<float> scale)
+        {
+            // Eight conventional CMYK samples convert independently without channel rearrangement.
+            Vector256<float> k = Vector256<float>.One - (c3 * scale);
+            c0 = (Vector256<float>.One - (c0 * scale)) * k;
+            c1 = (Vector256<float>.One - (c1 * scale)) * k;
+            c2 = (Vector256<float>.One - (c2 * scale)) * k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector512<float> c0, ref Vector512<float> c1, ref Vector512<float> c2, Vector512<float> c3, Vector512<float> maximumValue, Vector512<float> halfValue, Vector512<float> scale)
+        {
+            // Sixteen conventional CMYK samples convert independently without channel rearrangement.
+            Vector512<float> k = Vector512<float>.One - (c3 * scale);
+            c0 = (Vector512<float>.One - (c0 * scale)) * k;
+            c1 = (Vector512<float>.One - (c1 * scale)) * k;
+            c2 = (Vector512<float>.One - (c2 * scale)) * k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(float r, float g, float b, float maximumValue, float halfValue, float scale, out float c0, out float c1, out float c2, out float c3)
+        {
+            float c = maximumValue - r;
+            float m = maximumValue - g;
+            float y = maximumValue - b;
+            float k = MathF.Min(c, MathF.Min(m, y));
+
+            // Removing the shared black contribution requires division by the remaining range. Pure black
+            // consumes that range completely, so its chromatic components are defined as zero.
+            if (k >= maximumValue)
+            {
+                c = 0;
+                m = 0;
+                y = 0;
+            }
+            else
+            {
+                // One reciprocal normalizes C, M, and Y against their shared remaining range.
+                float reciprocal = 1F / (maximumValue - k);
+                c = (c - k) * reciprocal;
+                m = (m - k) * reciprocal;
+                y = (y - k) * reciprocal;
+            }
+
+            // TIFF stores conventional CMYK: scale normalized C/M/Y back into the sample domain and retain K.
+            c0 = c * maximumValue;
+            c1 = m * maximumValue;
+            c2 = y * maximumValue;
+            c3 = k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector128<float> r, Vector128<float> g, Vector128<float> b, Vector128<float> maximumValue, Vector128<float> halfValue, Vector128<float> scale, out Vector128<float> c0, out Vector128<float> c1, out Vector128<float> c2, out Vector128<float> c3)
+        {
+            Vector128<float> c = maximumValue - r;
+            Vector128<float> m = maximumValue - g;
+            Vector128<float> y = maximumValue - b;
+            Vector128<float> k = Vector128.Min(c, Vector128.Min(m, y));
+
+            // The all-bits mask clears the undefined zero-divisor result only in pure-black lanes.
+            Vector128<float> nonBlack = ~Vector128.Equals(k, maximumValue);
+            Vector128<float> reciprocal = Vector128<float>.One / (maximumValue - k);
+            c0 = (((c - k) * reciprocal) & nonBlack) * maximumValue;
+            c1 = (((m - k) * reciprocal) & nonBlack) * maximumValue;
+            c2 = (((y - k) * reciprocal) & nonBlack) * maximumValue;
+            c3 = k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector256<float> r, Vector256<float> g, Vector256<float> b, Vector256<float> maximumValue, Vector256<float> halfValue, Vector256<float> scale, out Vector256<float> c0, out Vector256<float> c1, out Vector256<float> c2, out Vector256<float> c3)
+        {
+            Vector256<float> c = maximumValue - r;
+            Vector256<float> m = maximumValue - g;
+            Vector256<float> y = maximumValue - b;
+            Vector256<float> k = Vector256.Min(c, Vector256.Min(m, y));
+
+            // Eight lanes independently clear the pure-black singularity before returning conventional CMYK.
+            Vector256<float> nonBlack = ~Vector256.Equals(k, maximumValue);
+            Vector256<float> reciprocal = Vector256<float>.One / (maximumValue - k);
+            c0 = (((c - k) * reciprocal) & nonBlack) * maximumValue;
+            c1 = (((m - k) * reciprocal) & nonBlack) * maximumValue;
+            c2 = (((y - k) * reciprocal) & nonBlack) * maximumValue;
+            c3 = k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector512<float> r, Vector512<float> g, Vector512<float> b, Vector512<float> maximumValue, Vector512<float> halfValue, Vector512<float> scale, out Vector512<float> c0, out Vector512<float> c1, out Vector512<float> c2, out Vector512<float> c3)
+        {
+            Vector512<float> c = maximumValue - r;
+            Vector512<float> m = maximumValue - g;
+            Vector512<float> y = maximumValue - b;
+            Vector512<float> k = Vector512.Min(c, Vector512.Min(m, y));
+
+            // Sixteen lanes retain the same branchless singularity handling and component layout.
+            Vector512<float> nonBlack = ~Vector512.Equals(k, maximumValue);
+            Vector512<float> reciprocal = Vector512<float>.One / (maximumValue - k);
+            c0 = (((c - k) * reciprocal) & nonBlack) * maximumValue;
+            c1 = (((m - k) * reciprocal) & nonBlack) * maximumValue;
+            c2 = (((y - k) * reciprocal) & nonBlack) * maximumValue;
+            c3 = k;
+        }
+
+        /// <inheritdoc/>
+        public static void ConvertToRgbInPlaceWithIcc(Configuration configuration, IccProfile profile, in ComponentValues values, float maximumValue)
+            => TiffCmykScalar.ConvertToRgbInPlaceWithIcc(configuration, profile, values, maximumValue);
+    }
+}

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.TiffYccKOperator.cs

@@ -0,0 +1,187 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.Common.Helpers;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    /// <summary>
+    /// Implements non-inverted TIFF JPEG YccK conversion for scalar and SIMD lanes.
+    /// </summary>
+    internal readonly struct TiffYccKOperator : IJpegColorConverterOperator
+    {
+        private const float SourceScale = 1F / 255F;
+
+        /// <inheritdoc/>
+        public static JpegColorSpace ColorSpace => JpegColorSpace.TiffYccK;
+
+        /// <inheritdoc/>
+        public static int ComponentCount => 4;
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref float c0, ref float c1, ref float c2, float c3, float maximumValue, float halfValue, float scale)
+        {
+            float y = c0 * scale;
+            float cb = (c1 - halfValue) * scale;
+            float cr = (c2 - halfValue) * scale;
+            float k = 1F - (c3 * scale);
+
+            // TIFF YccK is non-inverted: decode normalized YCbCr without integer rounding, then let the
+            // remaining light after K modulate all three channels.
+            c0 = (y + (YCbCrScalar.RCrMult * cr)) * k;
+            c1 = (y - (YCbCrScalar.GCbMult * cb) - (YCbCrScalar.GCrMult * cr)) * k;
+            c2 = (y + (YCbCrScalar.BCbMult * cb)) * k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector128<float> c0, ref Vector128<float> c1, ref Vector128<float> c2, Vector128<float> c3, Vector128<float> maximumValue, Vector128<float> halfValue, Vector128<float> scale)
+        {
+            Vector128<float> y = c0 * scale;
+            Vector128<float> cb = (c1 - halfValue) * scale;
+            Vector128<float> cr = (c2 - halfValue) * scale;
+            Vector128<float> k = Vector128<float>.One - (c3 * scale);
+
+            // Four lanes apply the non-rounded YCbCr matrix before their lane-aligned K modulation.
+            c0 = Vector128_.MultiplyAddEstimate(cr, Vector128.Create(YCbCrScalar.RCrMult), y) * k;
+            c1 = Vector128_.MultiplyAddEstimate(cr, Vector128.Create(-YCbCrScalar.GCrMult), Vector128_.MultiplyAddEstimate(cb, Vector128.Create(-YCbCrScalar.GCbMult), y)) * k;
+            c2 = Vector128_.MultiplyAddEstimate(cb, Vector128.Create(YCbCrScalar.BCbMult), y) * k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector256<float> c0, ref Vector256<float> c1, ref Vector256<float> c2, Vector256<float> c3, Vector256<float> maximumValue, Vector256<float> halfValue, Vector256<float> scale)
+        {
+            Vector256<float> y = c0 * scale;
+            Vector256<float> cb = (c1 - halfValue) * scale;
+            Vector256<float> cr = (c2 - halfValue) * scale;
+            Vector256<float> k = Vector256<float>.One - (c3 * scale);
+
+            // Eight lanes apply the non-rounded YCbCr matrix before their lane-aligned K modulation.
+            c0 = Vector256_.MultiplyAddEstimate(cr, Vector256.Create(YCbCrScalar.RCrMult), y) * k;
+            c1 = Vector256_.MultiplyAddEstimate(cr, Vector256.Create(-YCbCrScalar.GCrMult), Vector256_.MultiplyAddEstimate(cb, Vector256.Create(-YCbCrScalar.GCbMult), y)) * k;
+            c2 = Vector256_.MultiplyAddEstimate(cb, Vector256.Create(YCbCrScalar.BCbMult), y) * k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector512<float> c0, ref Vector512<float> c1, ref Vector512<float> c2, Vector512<float> c3, Vector512<float> maximumValue, Vector512<float> halfValue, Vector512<float> scale)
+        {
+            Vector512<float> y = c0 * scale;
+            Vector512<float> cb = (c1 - halfValue) * scale;
+            Vector512<float> cr = (c2 - halfValue) * scale;
+            Vector512<float> k = Vector512<float>.One - (c3 * scale);
+
+            // Sixteen lanes apply the non-rounded YCbCr matrix before their lane-aligned K modulation.
+            c0 = Vector512_.MultiplyAddEstimate(cr, Vector512.Create(YCbCrScalar.RCrMult), y) * k;
+            c1 = Vector512_.MultiplyAddEstimate(cr, Vector512.Create(-YCbCrScalar.GCrMult), Vector512_.MultiplyAddEstimate(cb, Vector512.Create(-YCbCrScalar.GCbMult), y)) * k;
+            c2 = Vector512_.MultiplyAddEstimate(cb, Vector512.Create(YCbCrScalar.BCbMult), y) * k;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(float r, float g, float b, float maximumValue, float halfValue, float scale, out float c0, out float c1, out float c2, out float c3)
+        {
+            r *= SourceScale;
+            g *= SourceScale;
+            b *= SourceScale;
+            float k = 1F - MathF.Max(r, MathF.Max(g, b));
+
+            // Dividing by the brightest channel removes K before YCbCr projection. Pure black has no
+            // chromatic direction, so it maps to zero luma and the neutral chroma midpoint.
+            if (k >= 1F)
+            {
+                c0 = 0;
+                c1 = halfValue;
+                c2 = halfValue;
+                c3 = maximumValue;
+                return;
+            }
+
+            float divisor = 1F / (1F - k);
+            r *= divisor;
+            g *= divisor;
+            b *= divisor;
+            c0 = ((0.299F * r) + (0.587F * g) + (0.114F * b)) * maximumValue;
+            c1 = halfValue + (((-0.168736F * r) + (-0.331264F * g) + (0.5F * b)) * maximumValue);
+            c2 = halfValue + (((0.5F * r) + (-0.418688F * g) + (-0.081312F * b)) * maximumValue);
+            c3 = k * maximumValue;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector128<float> r, Vector128<float> g, Vector128<float> b, Vector128<float> maximumValue, Vector128<float> halfValue, Vector128<float> scale, out Vector128<float> c0, out Vector128<float> c1, out Vector128<float> c2, out Vector128<float> c3)
+        {
+            Vector128<float> sourceScale = Vector128.Create(SourceScale);
+            r *= sourceScale;
+            g *= sourceScale;
+            b *= sourceScale;
+            Vector128<float> k = Vector128<float>.One - Vector128.Max(r, Vector128.Max(g, b));
+
+            // The mask assigns no chromatic direction to pure-black lanes while preserving neighboring pixels.
+            Vector128<float> nonBlack = ~Vector128.Equals(k, Vector128<float>.One);
+            Vector128<float> divisor = Vector128<float>.One / (Vector128<float>.One - k);
+            r = (r * divisor) & nonBlack;
+            g = (g * divisor) & nonBlack;
+            b = (b * divisor) & nonBlack;
+            c0 = Vector128_.MultiplyAddEstimate(Vector128.Create(0.299F), r, Vector128_.MultiplyAddEstimate(Vector128.Create(0.587F), g, Vector128.Create(0.114F) * b)) * maximumValue;
+            c1 = halfValue + (Vector128_.MultiplyAddEstimate(Vector128.Create(-0.168736F), r, Vector128_.MultiplyAddEstimate(Vector128.Create(-0.331264F), g, Vector128.Create(0.5F) * b)) * maximumValue);
+            c2 = halfValue + (Vector128_.MultiplyAddEstimate(Vector128.Create(0.5F), r, Vector128_.MultiplyAddEstimate(Vector128.Create(-0.418688F), g, Vector128.Create(-0.081312F) * b)) * maximumValue);
+            c3 = k * maximumValue;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector256<float> r, Vector256<float> g, Vector256<float> b, Vector256<float> maximumValue, Vector256<float> halfValue, Vector256<float> scale, out Vector256<float> c0, out Vector256<float> c1, out Vector256<float> c2, out Vector256<float> c3)
+        {
+            Vector256<float> sourceScale = Vector256.Create(SourceScale);
+            r *= sourceScale;
+            g *= sourceScale;
+            b *= sourceScale;
+            Vector256<float> k = Vector256<float>.One - Vector256.Max(r, Vector256.Max(g, b));
+
+            // Eight lanes normalize chromatic direction independently and retain neutral chroma for black.
+            Vector256<float> nonBlack = ~Vector256.Equals(k, Vector256<float>.One);
+            Vector256<float> divisor = Vector256<float>.One / (Vector256<float>.One - k);
+            r = (r * divisor) & nonBlack;
+            g = (g * divisor) & nonBlack;
+            b = (b * divisor) & nonBlack;
+            c0 = Vector256_.MultiplyAddEstimate(Vector256.Create(0.299F), r, Vector256_.MultiplyAddEstimate(Vector256.Create(0.587F), g, Vector256.Create(0.114F) * b)) * maximumValue;
+            c1 = halfValue + (Vector256_.MultiplyAddEstimate(Vector256.Create(-0.168736F), r, Vector256_.MultiplyAddEstimate(Vector256.Create(-0.331264F), g, Vector256.Create(0.5F) * b)) * maximumValue);
+            c2 = halfValue + (Vector256_.MultiplyAddEstimate(Vector256.Create(0.5F), r, Vector256_.MultiplyAddEstimate(Vector256.Create(-0.418688F), g, Vector256.Create(-0.081312F) * b)) * maximumValue);
+            c3 = k * maximumValue;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector512<float> r, Vector512<float> g, Vector512<float> b, Vector512<float> maximumValue, Vector512<float> halfValue, Vector512<float> scale, out Vector512<float> c0, out Vector512<float> c1, out Vector512<float> c2, out Vector512<float> c3)
+        {
+            Vector512<float> sourceScale = Vector512.Create(SourceScale);
+            r *= sourceScale;
+            g *= sourceScale;
+            b *= sourceScale;
+            Vector512<float> k = Vector512<float>.One - Vector512.Max(r, Vector512.Max(g, b));
+
+            // Sixteen lanes normalize chromatic direction independently and retain neutral chroma for black.
+            Vector512<float> nonBlack = ~Vector512.Equals(k, Vector512<float>.One);
+            Vector512<float> divisor = Vector512<float>.One / (Vector512<float>.One - k);
+            r = (r * divisor) & nonBlack;
+            g = (g * divisor) & nonBlack;
+            b = (b * divisor) & nonBlack;
+            c0 = Vector512_.MultiplyAddEstimate(Vector512.Create(0.299F), r, Vector512_.MultiplyAddEstimate(Vector512.Create(0.587F), g, Vector512.Create(0.114F) * b)) * maximumValue;
+            c1 = halfValue + (Vector512_.MultiplyAddEstimate(Vector512.Create(-0.168736F), r, Vector512_.MultiplyAddEstimate(Vector512.Create(-0.331264F), g, Vector512.Create(0.5F) * b)) * maximumValue);
+            c2 = halfValue + (Vector512_.MultiplyAddEstimate(Vector512.Create(0.5F), r, Vector512_.MultiplyAddEstimate(Vector512.Create(-0.418688F), g, Vector512.Create(-0.081312F) * b)) * maximumValue);
+            c3 = k * maximumValue;
+        }
+
+        /// <inheritdoc/>
+        public static void ConvertToRgbInPlaceWithIcc(Configuration configuration, IccProfile profile, in ComponentValues values, float maximumValue)
+            => TiffYccKScalar.ConvertToRgbInPlaceWithIcc(configuration, profile, values, maximumValue);
+    }
+}

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.YCbCrOperator.cs

@@ -0,0 +1,263 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.Common.Helpers;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    /// <summary>
+    /// Implements the JPEG YCbCr conversion formula for scalar and SIMD lanes.
+    /// </summary>
+    internal readonly struct YCbCrOperator : IJpegColorConverterOperator
+    {
+        /// <inheritdoc/>
+        public static JpegColorSpace ColorSpace => JpegColorSpace.YCbCr;
+
+        /// <inheritdoc/>
+        public static int ComponentCount => 3;
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref float c0,
+            ref float c1,
+            ref float c2,
+            float c3,
+            float maximumValue,
+            float halfValue,
+            float scale)
+        {
+            float y = c0;
+            float cb = c1 - halfValue;
+            float cr = c2 - halfValue;
+
+            // c0/c1/c2 initially mean Y/Cb/Cr. Chroma is centered around zero before applying
+            // the BT.601 matrix, then integer-domain RGB is rounded away from zero and normalized
+            // to [nominally] 0..1. Values intentionally remain unclamped because quantizing RGB into the
+            // destination pixel format owns saturation; retaining overshoot avoids discarding color information.
+            c0 = MathF.Round(y + (YCbCrScalar.RCrMult * cr), MidpointRounding.AwayFromZero) * scale;
+            c1 = MathF.Round(y - (YCbCrScalar.GCbMult * cb) - (YCbCrScalar.GCrMult * cr), MidpointRounding.AwayFromZero) * scale;
+            c2 = MathF.Round(y + (YCbCrScalar.BCbMult * cb), MidpointRounding.AwayFromZero) * scale;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector128<float> c0,
+            ref Vector128<float> c1,
+            ref Vector128<float> c2,
+            Vector128<float> c3,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale)
+        {
+            Vector128<float> y = c0;
+            Vector128<float> cb = c1 - halfValue;
+            Vector128<float> cr = c2 - halfValue;
+
+            // Lanes are four independent Y/Cb/Cr samples. MultiplyAddEstimate maps to FMA where available:
+            // R uses Cr, B uses Cb, and G subtracts both chroma contributions. Rounding occurs in the sample
+            // domain before the common normalization scale so all precisions use integer JPEG sample semantics.
+            Vector128<float> r = Vector128_.MultiplyAddEstimate(cr, Vector128.Create(YCbCrScalar.RCrMult), y);
+            Vector128<float> g = Vector128_.MultiplyAddEstimate(
+                cr,
+                Vector128.Create(-YCbCrScalar.GCrMult),
+                Vector128_.MultiplyAddEstimate(cb, Vector128.Create(-YCbCrScalar.GCbMult), y));
+            Vector128<float> b = Vector128_.MultiplyAddEstimate(cb, Vector128.Create(YCbCrScalar.BCbMult), y);
+
+            c0 = Vector128_.RoundToNearestInteger(r) * scale;
+            c1 = Vector128_.RoundToNearestInteger(g) * scale;
+            c2 = Vector128_.RoundToNearestInteger(b) * scale;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector256<float> c0,
+            ref Vector256<float> c1,
+            ref Vector256<float> c2,
+            Vector256<float> c3,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale)
+        {
+            Vector256<float> y = c0;
+            Vector256<float> cb = c1 - halfValue;
+            Vector256<float> cr = c2 - halfValue;
+
+            // These eight lanes have the same layout and BT.601 arithmetic as the Vector128 overload.
+            // Keeping an explicit overload allows the JIT to emit native YMM operations without a width
+            // switch or decomposing the vector into smaller values.
+            Vector256<float> r = Vector256_.MultiplyAddEstimate(cr, Vector256.Create(YCbCrScalar.RCrMult), y);
+            Vector256<float> g = Vector256_.MultiplyAddEstimate(
+                cr,
+                Vector256.Create(-YCbCrScalar.GCrMult),
+                Vector256_.MultiplyAddEstimate(cb, Vector256.Create(-YCbCrScalar.GCbMult), y));
+            Vector256<float> b = Vector256_.MultiplyAddEstimate(cb, Vector256.Create(YCbCrScalar.BCbMult), y);
+
+            c0 = Vector256_.RoundToNearestInteger(r) * scale;
+            c1 = Vector256_.RoundToNearestInteger(g) * scale;
+            c2 = Vector256_.RoundToNearestInteger(b) * scale;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(
+            ref Vector512<float> c0,
+            ref Vector512<float> c1,
+            ref Vector512<float> c2,
+            Vector512<float> c3,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale)
+        {
+            Vector512<float> y = c0;
+            Vector512<float> cb = c1 - halfValue;
+            Vector512<float> cr = c2 - halfValue;
+
+            // Sixteen independent samples occupy the ZMM lanes. The explicit constants are broadcasts;
+            // assembly inspection verifies the JIT hoists them from the loop and retains fused operations.
+            // The formula and rounding order remain identical to the narrower overloads.
+            Vector512<float> r = Vector512_.MultiplyAddEstimate(cr, Vector512.Create(YCbCrScalar.RCrMult), y);
+            Vector512<float> g = Vector512_.MultiplyAddEstimate(
+                cr,
+                Vector512.Create(-YCbCrScalar.GCrMult),
+                Vector512_.MultiplyAddEstimate(cb, Vector512.Create(-YCbCrScalar.GCbMult), y));
+            Vector512<float> b = Vector512_.MultiplyAddEstimate(cb, Vector512.Create(YCbCrScalar.BCbMult), y);
+
+            c0 = Vector512_.RoundToNearestInteger(r) * scale;
+            c1 = Vector512_.RoundToNearestInteger(g) * scale;
+            c2 = Vector512_.RoundToNearestInteger(b) * scale;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            float r,
+            float g,
+            float b,
+            float maximumValue,
+            float halfValue,
+            float scale,
+            out float c0,
+            out float c1,
+            out float c2,
+            out float c3)
+        {
+            // The RGB inputs are unnormalized 0..255 encoder lanes. The BT.601 luma weights form Y,
+            // while the signed chroma projections are biased by halfValue into the JPEG sample domain.
+            // YCbCr has no fourth component, so c3 is a compile-time-unused placeholder for the shared loop.
+            c0 = (0.299F * r) + (0.587F * g) + (0.114F * b);
+            c1 = halfValue - (0.168736F * r) - (0.331264F * g) + (0.5F * b);
+            c2 = halfValue + (0.5F * r) - (0.418688F * g) - (0.081312F * b);
+            c3 = 0;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector128<float> r,
+            Vector128<float> g,
+            Vector128<float> b,
+            Vector128<float> maximumValue,
+            Vector128<float> halfValue,
+            Vector128<float> scale,
+            out Vector128<float> c0,
+            out Vector128<float> c1,
+            out Vector128<float> c2,
+            out Vector128<float> c3)
+        {
+            // Each vector holds four consecutive values from one RGB plane. The nested multiply-add sequence
+            // produces four Y lanes, four Cb lanes, and four Cr lanes without transposition. The association
+            // exposes two FMA opportunities per output while preserving the scalar formula's term grouping.
+            c0 = Vector128_.MultiplyAddEstimate(
+                Vector128.Create(0.299F),
+                r,
+                Vector128_.MultiplyAddEstimate(Vector128.Create(0.587F), g, Vector128.Create(0.114F) * b));
+            c1 = halfValue + Vector128_.MultiplyAddEstimate(
+                Vector128.Create(-0.168736F),
+                r,
+                Vector128_.MultiplyAddEstimate(Vector128.Create(-0.331264F), g, Vector128.Create(0.5F) * b));
+            c2 = halfValue + Vector128_.MultiplyAddEstimate(
+                Vector128.Create(0.5F),
+                r,
+                Vector128_.MultiplyAddEstimate(Vector128.Create(-0.418688F), g, Vector128.Create(-0.081312F) * b));
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector256<float> r,
+            Vector256<float> g,
+            Vector256<float> b,
+            Vector256<float> maximumValue,
+            Vector256<float> halfValue,
+            Vector256<float> scale,
+            out Vector256<float> c0,
+            out Vector256<float> c1,
+            out Vector256<float> c2,
+            out Vector256<float> c3)
+        {
+            // Eight planar RGB samples use the identical association as Vector128, allowing direct YMM FMA
+            // generation while preserving the component-per-vector output layout.
+            c0 = Vector256_.MultiplyAddEstimate(
+                Vector256.Create(0.299F),
+                r,
+                Vector256_.MultiplyAddEstimate(Vector256.Create(0.587F), g, Vector256.Create(0.114F) * b));
+            c1 = halfValue + Vector256_.MultiplyAddEstimate(
+                Vector256.Create(-0.168736F),
+                r,
+                Vector256_.MultiplyAddEstimate(Vector256.Create(-0.331264F), g, Vector256.Create(0.5F) * b));
+            c2 = halfValue + Vector256_.MultiplyAddEstimate(
+                Vector256.Create(0.5F),
+                r,
+                Vector256_.MultiplyAddEstimate(Vector256.Create(-0.418688F), g, Vector256.Create(-0.081312F) * b));
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(
+            Vector512<float> r,
+            Vector512<float> g,
+            Vector512<float> b,
+            Vector512<float> maximumValue,
+            Vector512<float> halfValue,
+            Vector512<float> scale,
+            out Vector512<float> c0,
+            out Vector512<float> c1,
+            out Vector512<float> c2,
+            out Vector512<float> c3)
+        {
+            // Sixteen planar RGB samples use the same nested form. Constants are lane broadcasts and c3 is
+            // deliberately zero because the shared traversal removes the unused fourth store for this operator.
+            c0 = Vector512_.MultiplyAddEstimate(
+                Vector512.Create(0.299F),
+                r,
+                Vector512_.MultiplyAddEstimate(Vector512.Create(0.587F), g, Vector512.Create(0.114F) * b));
+            c1 = halfValue + Vector512_.MultiplyAddEstimate(
+                Vector512.Create(-0.168736F),
+                r,
+                Vector512_.MultiplyAddEstimate(Vector512.Create(-0.331264F), g, Vector512.Create(0.5F) * b));
+            c2 = halfValue + Vector512_.MultiplyAddEstimate(
+                Vector512.Create(0.5F),
+                r,
+                Vector512_.MultiplyAddEstimate(Vector512.Create(-0.418688F), g, Vector512.Create(-0.081312F) * b));
+            c3 = default;
+        }
+
+        /// <inheritdoc/>
+        public static void ConvertToRgbInPlaceWithIcc(
+            Configuration configuration,
+            IccProfile profile,
+            in ComponentValues values,
+            float maximumValue)
+            => YCbCrScalar.ConvertToRgbInPlaceWithIcc(configuration, profile, values, maximumValue);
+    }
+}

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.YccKOperator.cs

@@ -0,0 +1,135 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.Common.Helpers;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
+
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+    /// <summary>
+    /// Implements inverted JPEG YccK conversion for scalar and SIMD lanes.
+    /// </summary>
+    internal readonly struct YccKOperator : IJpegColorConverterOperator
+    {
+        /// <inheritdoc/>
+        public static JpegColorSpace ColorSpace => JpegColorSpace.Ycck;
+
+        /// <inheritdoc/>
+        public static int ComponentCount => 4;
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref float c0, ref float c1, ref float c2, float c3, float maximumValue, float halfValue, float scale)
+        {
+            float y = c0;
+            float cb = c1 - halfValue;
+            float cr = c2 - halfValue;
+            float scaledK = c3 * scale * scale;
+
+            // YccK first reconstructs inverted RGB in the integer sample domain. Rounding must occur before
+            // subtracting from max and applying K because changing that order changes encoded JPEG semantics.
+            c0 = (maximumValue - MathF.Round(y + (YCbCrScalar.RCrMult * cr), MidpointRounding.AwayFromZero)) * scaledK;
+            c1 = (maximumValue - MathF.Round(y - (YCbCrScalar.GCbMult * cb) - (YCbCrScalar.GCrMult * cr), MidpointRounding.AwayFromZero)) * scaledK;
+            c2 = (maximumValue - MathF.Round(y + (YCbCrScalar.BCbMult * cb), MidpointRounding.AwayFromZero)) * scaledK;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector128<float> c0, ref Vector128<float> c1, ref Vector128<float> c2, Vector128<float> c3, Vector128<float> maximumValue, Vector128<float> halfValue, Vector128<float> scale)
+        {
+            Vector128<float> y = c0;
+            Vector128<float> cb = c1 - halfValue;
+            Vector128<float> cr = c2 - halfValue;
+            Vector128<float> scaledK = c3 * scale * scale;
+
+            // Four lanes reconstruct YCbCr concurrently; each rounded result is inverted and modulated by its K lane.
+            Vector128<float> r = Vector128_.MultiplyAddEstimate(cr, Vector128.Create(YCbCrScalar.RCrMult), y);
+            Vector128<float> g = Vector128_.MultiplyAddEstimate(cr, Vector128.Create(-YCbCrScalar.GCrMult), Vector128_.MultiplyAddEstimate(cb, Vector128.Create(-YCbCrScalar.GCbMult), y));
+            Vector128<float> b = Vector128_.MultiplyAddEstimate(cb, Vector128.Create(YCbCrScalar.BCbMult), y);
+            c0 = (maximumValue - Vector128_.RoundToNearestInteger(r)) * scaledK;
+            c1 = (maximumValue - Vector128_.RoundToNearestInteger(g)) * scaledK;
+            c2 = (maximumValue - Vector128_.RoundToNearestInteger(b)) * scaledK;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector256<float> c0, ref Vector256<float> c1, ref Vector256<float> c2, Vector256<float> c3, Vector256<float> maximumValue, Vector256<float> halfValue, Vector256<float> scale)
+        {
+            Vector256<float> y = c0;
+            Vector256<float> cb = c1 - halfValue;
+            Vector256<float> cr = c2 - halfValue;
+            Vector256<float> scaledK = c3 * scale * scale;
+
+            // Eight lanes retain planar alignment from Y/Cb/Cr/K through normalized RGB.
+            Vector256<float> r = Vector256_.MultiplyAddEstimate(cr, Vector256.Create(YCbCrScalar.RCrMult), y);
+            Vector256<float> g = Vector256_.MultiplyAddEstimate(cr, Vector256.Create(-YCbCrScalar.GCrMult), Vector256_.MultiplyAddEstimate(cb, Vector256.Create(-YCbCrScalar.GCbMult), y));
+            Vector256<float> b = Vector256_.MultiplyAddEstimate(cb, Vector256.Create(YCbCrScalar.BCbMult), y);
+            c0 = (maximumValue - Vector256_.RoundToNearestInteger(r)) * scaledK;
+            c1 = (maximumValue - Vector256_.RoundToNearestInteger(g)) * scaledK;
+            c2 = (maximumValue - Vector256_.RoundToNearestInteger(b)) * scaledK;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertToRgb(ref Vector512<float> c0, ref Vector512<float> c1, ref Vector512<float> c2, Vector512<float> c3, Vector512<float> maximumValue, Vector512<float> halfValue, Vector512<float> scale)
+        {
+            Vector512<float> y = c0;
+            Vector512<float> cb = c1 - halfValue;
+            Vector512<float> cr = c2 - halfValue;
+            Vector512<float> scaledK = c3 * scale * scale;
+
+            // Sixteen lanes use the same matrix, rounding, inversion, and K modulation order as scalar code.
+            Vector512<float> r = Vector512_.MultiplyAddEstimate(cr, Vector512.Create(YCbCrScalar.RCrMult), y);
+            Vector512<float> g = Vector512_.MultiplyAddEstimate(cr, Vector512.Create(-YCbCrScalar.GCrMult), Vector512_.MultiplyAddEstimate(cb, Vector512.Create(-YCbCrScalar.GCbMult), y));
+            Vector512<float> b = Vector512_.MultiplyAddEstimate(cb, Vector512.Create(YCbCrScalar.BCbMult), y);
+            c0 = (maximumValue - Vector512_.RoundToNearestInteger(r)) * scaledK;
+            c1 = (maximumValue - Vector512_.RoundToNearestInteger(g)) * scaledK;
+            c2 = (maximumValue - Vector512_.RoundToNearestInteger(b)) * scaledK;
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(float r, float g, float b, float maximumValue, float halfValue, float scale, out float c0, out float c1, out float c2, out float c3)
+        {
+            // CMYK extraction supplies inverted chromatic samples and K. Reflecting the first three results
+            // reconstructs the chromatic RGB that YCbCr encodes, while K passes through untouched.
+            CmykOperator.ConvertFromRgb(r, g, b, maximumValue, halfValue, scale, out float c, out float m, out float y, out c3);
+            YCbCrOperator.ConvertFromRgb(maximumValue - c, maximumValue - m, maximumValue - y, maximumValue, halfValue, scale, out c0, out c1, out c2, out _);
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector128<float> r, Vector128<float> g, Vector128<float> b, Vector128<float> maximumValue, Vector128<float> halfValue, Vector128<float> scale, out Vector128<float> c0, out Vector128<float> c1, out Vector128<float> c2, out Vector128<float> c3)
+        {
+            // Static constrained calls inline both stages, keeping four pixels in registers without materializing CMYK planes.
+            CmykOperator.ConvertFromRgb(r, g, b, maximumValue, halfValue, scale, out Vector128<float> c, out Vector128<float> m, out Vector128<float> y, out c3);
+            YCbCrOperator.ConvertFromRgb(maximumValue - c, maximumValue - m, maximumValue - y, maximumValue, halfValue, scale, out c0, out c1, out c2, out _);
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector256<float> r, Vector256<float> g, Vector256<float> b, Vector256<float> maximumValue, Vector256<float> halfValue, Vector256<float> scale, out Vector256<float> c0, out Vector256<float> c1, out Vector256<float> c2, out Vector256<float> c3)
+        {
+            // Eight pixels flow through CMYK extraction and YCbCr projection entirely in YMM registers.
+            CmykOperator.ConvertFromRgb(r, g, b, maximumValue, halfValue, scale, out Vector256<float> c, out Vector256<float> m, out Vector256<float> y, out c3);
+            YCbCrOperator.ConvertFromRgb(maximumValue - c, maximumValue - m, maximumValue - y, maximumValue, halfValue, scale, out c0, out c1, out c2, out _);
+        }
+
+        /// <inheritdoc/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertFromRgb(Vector512<float> r, Vector512<float> g, Vector512<float> b, Vector512<float> maximumValue, Vector512<float> halfValue, Vector512<float> scale, out Vector512<float> c0, out Vector512<float> c1, out Vector512<float> c2, out Vector512<float> c3)
+        {
+            // Sixteen pixels flow through both mathematical stages in registers without materializing intermediate planes.
+            CmykOperator.ConvertFromRgb(r, g, b, maximumValue, halfValue, scale, out Vector512<float> c, out Vector512<float> m, out Vector512<float> y, out c3);
+            YCbCrOperator.ConvertFromRgb(maximumValue - c, maximumValue - m, maximumValue - y, maximumValue, halfValue, scale, out c0, out c1, out c2, out _);
+        }
+
+        /// <inheritdoc/>
+        public static void ConvertToRgbInPlaceWithIcc(Configuration configuration, IccProfile profile, in ComponentValues values, float maximumValue)
+            => YccKScalar.ConvertToRgbInPlaceWithIcc(configuration, profile, values, maximumValue);
+    }
+}

src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverterBase.cs

@@ -248,161 +248,50 @@ internal abstract partial class JpegColorConverterBase
     /// Returns the <see cref="JpegColorConverterBase"/>s for the YCbCr colorspace.
     /// </summary>
     /// <param name="precision">The precision in bits.</param>
-    private static JpegColorConverterBase GetYCbCrConverter(int precision)
+    private static JpegColorConverter<YCbCrOperator> GetYCbCrConverter(int precision)
-    {
+        => new JpegColorConverter<YCbCrOperator>(precision);
-        if (JpegColorConverterVector512.IsSupported)
-        {
-            return new YCbCrVector512(precision);
-        }
-
-        if (JpegColorConverterVector256.IsSupported)
-        {
-            return new YCbCrVector256(precision);
-        }
-
-        if (JpegColorConverterVector128.IsSupported)
-        {
-            return new YCbCrVector128(precision);
-        }
-
-        return new YCbCrScalar(precision);
-    }
 
     /// <summary>
     /// Returns the <see cref="JpegColorConverterBase"/>s for the YccK colorspace.
     /// </summary>
     /// <param name="precision">The precision in bits.</param>
-    private static JpegColorConverterBase GetYccKConverter(int precision)
+    private static JpegColorConverter<YccKOperator> GetYccKConverter(int precision)
-    {
+        => new JpegColorConverter<YccKOperator>(precision);
-        if (JpegColorConverterVector512.IsSupported)
-        {
-            return new YccKVector512(precision);
-        }
-
-        if (JpegColorConverterVector256.IsSupported)
-        {
-            return new YccKVector256(precision);
-        }
-
-        if (JpegColorConverterVector128.IsSupported)
-        {
-            return new YccKVector128(precision);
-        }
-
-        return new YccKScalar(precision);
-    }
 
     /// <summary>
     /// Returns the <see cref="JpegColorConverterBase"/>s for the CMYK colorspace.
     /// </summary>
     /// <param name="precision">The precision in bits.</param>
-    private static JpegColorConverterBase GetCmykConverter(int precision)
+    private static JpegColorConverter<CmykOperator> GetCmykConverter(int precision)
-    {
+        => new JpegColorConverter<CmykOperator>(precision);
-        if (JpegColorConverterVector512.IsSupported)
-        {
-            return new CmykVector512(precision);
-        }
-
-        if (JpegColorConverterVector256.IsSupported)
-        {
-            return new CmykVector256(precision);
-        }
-
-        if (JpegColorConverterVector128.IsSupported)
-        {
-            return new CmykVector128(precision);
-        }
-
-        return new CmykScalar(precision);
-    }
 
     /// <summary>
     /// Returns the <see cref="JpegColorConverterBase"/>s for the gray scale colorspace.
     /// </summary>
     /// <param name="precision">The precision in bits.</param>
-    private static JpegColorConverterBase GetGrayScaleConverter(int precision)
+    private static JpegColorConverter<GrayScaleOperator> GetGrayScaleConverter(int precision)
-    {
+        => new JpegColorConverter<GrayScaleOperator>(precision);
-        if (JpegColorConverterVector512.IsSupported)
-        {
-            return new GrayScaleVector512(precision);
-        }
-
-        if (JpegColorConverterVector256.IsSupported)
-        {
-            return new GrayScaleVector256(precision);
-        }
-
-        if (JpegColorConverterVector128.IsSupported)
-        {
-            return new GrayScaleVector128(precision);
-        }
-
-        return new GrayScaleScalar(precision);
-    }
 
     /// <summary>
     /// Returns the <see cref="JpegColorConverterBase"/>s for the RGB colorspace.
     /// </summary>
     /// <param name="precision">The precision in bits.</param>
-    private static JpegColorConverterBase GetRgbConverter(int precision)
+    private static JpegColorConverter<RgbOperator> GetRgbConverter(int precision)
-    {
+        => new JpegColorConverter<RgbOperator>(precision);
-        if (JpegColorConverterVector512.IsSupported)
-        {
-            return new RgbVector512(precision);
-        }
-
-        if (JpegColorConverterVector256.IsSupported)
-        {
-            return new RgbVector256(precision);
-        }
-
-        if (JpegColorConverterVector128.IsSupported)
-        {
-            return new RgbVector128(precision);
-        }
 
-        return new RgbScalar(precision);
+    /// <summary>
-    }
+    /// Returns the <see cref="JpegColorConverterBase"/> for non-inverted TIFF CMYK.
-
+    /// </summary>
-    private static JpegColorConverterBase GetTiffCmykConverter(int precision)
+    /// <param name="precision">The precision in bits.</param>
-    {
+    private static JpegColorConverter<TiffCmykOperator> GetTiffCmykConverter(int precision)
-        if (JpegColorConverterVector512.IsSupported)
+        => new JpegColorConverter<TiffCmykOperator>(precision);
-        {
-            return new TiffCmykVector512(precision);
-        }
-
-        if (JpegColorConverterVector256.IsSupported)
-        {
-            return new TiffCmykVector256(precision);
-        }
-
-        if (JpegColorConverterVector128.IsSupported)
-        {
-            return new TiffCmykVector128(precision);
-        }
-
-        return new TiffCmykScalar(precision);
-    }
-
-    private static JpegColorConverterBase GetTiffYccKConverter(int precision)
-    {
-        if (JpegColorConverterVector512.IsSupported)
-        {
-            return new TiffYccKVector512(precision);
-        }
-
-        if (JpegColorConverterVector256.IsSupported)
-        {
-            return new TiffYccKVector256(precision);
-        }
-
-        if (JpegColorConverterVector128.IsSupported)
-        {
-            return new TiffYccKVector128(precision);
-        }
 
-        return new TiffYccKScalar(precision);
+    /// <summary>
-    }
+    /// Returns the <see cref="JpegColorConverterBase"/> for non-inverted TIFF YccK.
+    /// </summary>
+    /// <param name="precision">The precision in bits.</param>
+    private static JpegColorConverter<TiffYccKOperator> GetTiffYccKConverter(int precision)
+        => new JpegColorConverter<TiffYccKOperator>(precision);
 
     /// <summary>
     /// A stack-only struct to reference the input buffers using <see cref="ReadOnlySpan{T}"/>-s.

tests/ImageSharp.Benchmarks/Codecs/Jpeg/ColorConversion/ColorConversionBenchmark.cs

@@ -51,6 +51,7 @@ public abstract class ColorConversionBenchmark
 
             // no need to dispose when buffer is not array owner
             buffers[i] = Configuration.Default.MemoryAllocator.Allocate2D<float>(values.Length, 1);
+            values.CopyTo(buffers[i].DangerousGetRowSpan(0));
         }
 
         return buffers;

tests/ImageSharp.Benchmarks/Codecs/Jpeg/ColorConversion/JpegColorConverterOperatorComparison.cs

@@ -0,0 +1,239 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Columns;
+using BenchmarkDotNet.Configs;
+using SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+namespace SixLabors.ImageSharp.Benchmarks.Codecs.Jpeg;
+
+/// <summary>
+/// Compares each shared operator converter with the Vector512 converter it replaces.
+/// </summary>
+[Config(typeof(Config.Standard))]
+[GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory)]
+[CategoriesColumn]
+public class JpegColorConverterOperatorComparison
+{
+    private JpegColorConverterBase legacy;
+    private JpegColorConverterBase operatorConverter;
+    private float[] legacyC0;
+    private float[] legacyC1;
+    private float[] legacyC2;
+    private float[] legacyC3;
+    private float[] operatorC0;
+    private float[] operatorC1;
+    private float[] operatorC2;
+    private float[] operatorC3;
+    private float[] r;
+    private float[] g;
+    private float[] b;
+    private int componentCount;
+
+    /// <summary>
+    /// Gets or sets the color model measured by the current benchmark case.
+    /// </summary>
+    [Params(
+        JpegColorModel.Grayscale,
+        JpegColorModel.Rgb,
+        JpegColorModel.Cmyk,
+        JpegColorModel.YCbCr,
+        JpegColorModel.YccK,
+        JpegColorModel.TiffCmyk,
+        JpegColorModel.TiffYccK)]
+    public JpegColorModel ColorModel { get; set; }
+
+    /// <summary>
+    /// Gets or sets the number of pixels converted by each invocation.
+    /// </summary>
+    [Params(128, 1024)]
+    public int Count { get; set; }
+
+    /// <summary>
+    /// Creates equivalent legacy and operator converters and their independent component buffers.
+    /// </summary>
+    [GlobalSetup]
+    public void Setup()
+    {
+        (JpegColorConverterBase Legacy, JpegColorConverterBase Operator, int ComponentCount) converters =
+            this.ColorModel switch
+        {
+            JpegColorModel.Grayscale => (
+                new JpegColorConverterBase.GrayScaleVector512(8),
+                new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.GrayScaleOperator>(8),
+                1),
+            JpegColorModel.Rgb => (
+                new JpegColorConverterBase.RgbVector512(8),
+                new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.RgbOperator>(8),
+                3),
+            JpegColorModel.Cmyk => (
+                new JpegColorConverterBase.CmykVector512(8),
+                new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.CmykOperator>(8),
+                4),
+            JpegColorModel.YCbCr => (
+                new JpegColorConverterBase.YCbCrVector512(8),
+                new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YCbCrOperator>(8),
+                3),
+            JpegColorModel.YccK => (
+                new JpegColorConverterBase.YccKVector512(8),
+                new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YccKOperator>(8),
+                4),
+            JpegColorModel.TiffCmyk => (
+                new JpegColorConverterBase.TiffCmykVector512(8),
+                new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.TiffCmykOperator>(8),
+                4),
+            JpegColorModel.TiffYccK => (
+                new JpegColorConverterBase.TiffYccKVector512(8),
+                new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.TiffYccKOperator>(8),
+                4),
+            _ => throw new InvalidOperationException(),
+        };
+
+        (this.legacy, this.operatorConverter, this.componentCount) = converters;
+
+        Random random = new(42);
+        this.legacyC0 = CreateRandomValues(this.Count, random);
+        this.legacyC1 = CreateRandomValues(this.Count, random);
+        this.legacyC2 = CreateRandomValues(this.Count, random);
+        this.legacyC3 = CreateRandomValues(this.Count, random);
+        this.operatorC0 = this.legacyC0.ToArray();
+        this.operatorC1 = this.legacyC1.ToArray();
+        this.operatorC2 = this.legacyC2.ToArray();
+        this.operatorC3 = this.legacyC3.ToArray();
+        this.r = CreateRandomValues(this.Count, random);
+        this.g = CreateRandomValues(this.Count, random);
+        this.b = CreateRandomValues(this.Count, random);
+    }
+
+    /// <summary>
+    /// Converts JPEG components to RGB using the replaced Vector512 implementation.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("ToRgb")]
+    public void LegacyToRgb()
+    {
+        JpegColorConverterBase.ComponentValues values = this.CreateLegacyValues();
+
+        this.legacy.ConvertToRgbInPlace(values);
+    }
+
+    /// <summary>
+    /// Converts JPEG components to RGB using the shared operator traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("ToRgb")]
+    public void OperatorToRgb()
+    {
+        JpegColorConverterBase.ComponentValues values = this.CreateOperatorValues();
+
+        this.operatorConverter.ConvertToRgbInPlace(values);
+    }
+
+    /// <summary>
+    /// Converts RGB to JPEG components using the replaced Vector512 implementation.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("FromRgb")]
+    public void LegacyFromRgb()
+    {
+        JpegColorConverterBase.ComponentValues values = this.CreateLegacyValues();
+
+        this.legacy.ConvertFromRgb(values, this.r, this.g, this.b);
+    }
+
+    /// <summary>
+    /// Converts RGB to JPEG components using the shared operator traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("FromRgb")]
+    public void OperatorFromRgb()
+    {
+        JpegColorConverterBase.ComponentValues values = this.CreateOperatorValues();
+
+        this.operatorConverter.ConvertFromRgb(values, this.r, this.g, this.b);
+    }
+
+    /// <summary>
+    /// Creates a component view over the buffers owned by the legacy converter.
+    /// </summary>
+    /// <returns>The component view for the configured color model.</returns>
+    private JpegColorConverterBase.ComponentValues CreateLegacyValues()
+        => new(
+            this.componentCount,
+            this.legacyC0,
+            this.componentCount > 1 ? this.legacyC1 : this.legacyC0,
+            this.componentCount > 2 ? this.legacyC2 : this.legacyC0,
+            this.componentCount > 3 ? this.legacyC3 : []);
+
+    /// <summary>
+    /// Creates a component view over the buffers owned by the operator converter.
+    /// </summary>
+    /// <returns>The component view for the configured color model.</returns>
+    private JpegColorConverterBase.ComponentValues CreateOperatorValues()
+        => new(
+            this.componentCount,
+            this.operatorC0,
+            this.componentCount > 1 ? this.operatorC1 : this.operatorC0,
+            this.componentCount > 2 ? this.operatorC2 : this.operatorC0,
+            this.componentCount > 3 ? this.operatorC3 : []);
+
+    /// <summary>
+    /// Creates deterministic sample-domain values for one component plane.
+    /// </summary>
+    /// <param name="length">The number of samples to create.</param>
+    /// <param name="random">The deterministic random source shared by setup.</param>
+    /// <returns>The populated component plane.</returns>
+    private static float[] CreateRandomValues(int length, Random random)
+    {
+        float[] values = new float[length];
+
+        for (int i = 0; i < values.Length; i++)
+        {
+            values[i] = (float)random.NextDouble() * 255F;
+        }
+
+        return values;
+    }
+
+    /// <summary>
+    /// Identifies the JPEG color model used by a benchmark case.
+    /// </summary>
+    public enum JpegColorModel
+    {
+        /// <summary>
+        /// One luminance component.
+        /// </summary>
+        Grayscale,
+
+        /// <summary>
+        /// Three direct RGB components.
+        /// </summary>
+        Rgb,
+
+        /// <summary>
+        /// Four inverted Adobe CMYK components.
+        /// </summary>
+        Cmyk,
+
+        /// <summary>
+        /// Three JPEG YCbCr components.
+        /// </summary>
+        YCbCr,
+
+        /// <summary>
+        /// Four inverted Adobe YCCK components.
+        /// </summary>
+        YccK,
+
+        /// <summary>
+        /// Four non-inverted TIFF CMYK components.
+        /// </summary>
+        TiffCmyk,
+
+        /// <summary>
+        /// Four non-inverted TIFF YCCK components.
+        /// </summary>
+        TiffYccK,
+    }
+}

tests/ImageSharp.Benchmarks/Codecs/Jpeg/ColorConversion/JpegColorConverterTraversalAssembly.cs

@@ -0,0 +1,325 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Columns;
+using BenchmarkDotNet.Configs;
+using SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+namespace SixLabors.ImageSharp.Benchmarks.Codecs.Jpeg;
+
+/// <summary>
+/// Exposes every closed JPEG operator traversal beside the Vector512 implementation it replaces.
+/// </summary>
+/// <remarks>
+/// A 63-pixel buffer leaves 256-bit, 128-bit, and scalar remainders after the 512-bit loop, making
+/// every operator overload visible in the generated traversal assembly on AVX-512 hardware.
+/// </remarks>
+[Config(typeof(Config.Analysis))]
+[GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory)]
+[CategoriesColumn]
+public class JpegColorConverterTraversalAssembly
+{
+    private const int Count = 63;
+
+    private readonly JpegColorConverterBase.GrayScaleVector512 grayscaleLegacy = new(8);
+    private readonly JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.GrayScaleOperator> grayscaleOperator = new(8);
+    private readonly JpegColorConverterBase.RgbVector512 rgbLegacy = new(8);
+    private readonly JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.RgbOperator> rgbOperator = new(8);
+    private readonly JpegColorConverterBase.CmykVector512 cmykLegacy = new(8);
+    private readonly JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.CmykOperator> cmykOperator = new(8);
+    private readonly JpegColorConverterBase.YCbCrVector512 yCbCrLegacy = new(8);
+    private readonly JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YCbCrOperator> yCbCrOperator = new(8);
+    private readonly JpegColorConverterBase.YccKVector512 yccKLegacy = new(8);
+    private readonly JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YccKOperator> yccKOperator = new(8);
+    private readonly JpegColorConverterBase.TiffCmykVector512 tiffCmykLegacy = new(8);
+    private readonly JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.TiffCmykOperator> tiffCmykOperator = new(8);
+    private readonly JpegColorConverterBase.TiffYccKVector512 tiffYccKLegacy = new(8);
+    private readonly JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.TiffYccKOperator> tiffYccKOperator = new(8);
+
+    private readonly float[] legacyC0 = new float[Count];
+    private readonly float[] legacyC1 = new float[Count];
+    private readonly float[] legacyC2 = new float[Count];
+    private readonly float[] legacyC3 = new float[Count];
+    private readonly float[] operatorC0 = new float[Count];
+    private readonly float[] operatorC1 = new float[Count];
+    private readonly float[] operatorC2 = new float[Count];
+    private readonly float[] operatorC3 = new float[Count];
+    private readonly float[] r = new float[Count];
+    private readonly float[] g = new float[Count];
+    private readonly float[] b = new float[Count];
+
+    /// <summary>
+    /// Populates the component and RGB planes with deterministic sample-domain values.
+    /// </summary>
+    [GlobalSetup]
+    public void Setup()
+    {
+        Random random = new(42);
+
+        for (int i = 0; i < Count; i++)
+        {
+            // Independent non-constant lanes prevent the JIT from folding arithmetic or mask decisions.
+            this.legacyC0[i] = this.operatorC0[i] = (float)random.NextDouble() * 255F;
+            this.legacyC1[i] = this.operatorC1[i] = (float)random.NextDouble() * 255F;
+            this.legacyC2[i] = this.operatorC2[i] = (float)random.NextDouble() * 255F;
+            this.legacyC3[i] = this.operatorC3[i] = (float)random.NextDouble() * 255F;
+            this.r[i] = (float)random.NextDouble() * 255F;
+            this.g[i] = (float)random.NextDouble() * 255F;
+            this.b[i] = (float)random.NextDouble() * 255F;
+        }
+    }
+
+    /// <summary>
+    /// Runs the replaced grayscale component-to-RGB traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("Grayscale.ToRgb")]
+    public void GrayscaleLegacyToRgb()
+        => this.grayscaleLegacy.ConvertToRgbInPlace(this.CreateLegacyValues(1));
+
+    /// <summary>
+    /// Runs the shared grayscale component-to-RGB traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("Grayscale.ToRgb")]
+    public void GrayscaleOperatorToRgb()
+        => this.grayscaleOperator.ConvertToRgbInPlace(this.CreateOperatorValues(1));
+
+    /// <summary>
+    /// Runs the replaced grayscale RGB-to-component traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("Grayscale.FromRgb")]
+    public void GrayscaleLegacyFromRgb()
+        => this.grayscaleLegacy.ConvertFromRgb(this.CreateLegacyValues(1), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the shared grayscale RGB-to-component traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("Grayscale.FromRgb")]
+    public void GrayscaleOperatorFromRgb()
+        => this.grayscaleOperator.ConvertFromRgb(this.CreateOperatorValues(1), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the replaced RGB component-to-RGB traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("Rgb.ToRgb")]
+    public void RgbLegacyToRgb()
+        => this.rgbLegacy.ConvertToRgbInPlace(this.CreateLegacyValues(3));
+
+    /// <summary>
+    /// Runs the shared RGB component-to-RGB traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("Rgb.ToRgb")]
+    public void RgbOperatorToRgb()
+        => this.rgbOperator.ConvertToRgbInPlace(this.CreateOperatorValues(3));
+
+    /// <summary>
+    /// Runs the replaced RGB RGB-to-component traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("Rgb.FromRgb")]
+    public void RgbLegacyFromRgb()
+        => this.rgbLegacy.ConvertFromRgb(this.CreateLegacyValues(3), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the shared RGB RGB-to-component traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("Rgb.FromRgb")]
+    public void RgbOperatorFromRgb()
+        => this.rgbOperator.ConvertFromRgb(this.CreateOperatorValues(3), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the replaced CMYK component-to-RGB traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("Cmyk.ToRgb")]
+    public void CmykLegacyToRgb()
+        => this.cmykLegacy.ConvertToRgbInPlace(this.CreateLegacyValues(4));
+
+    /// <summary>
+    /// Runs the shared CMYK component-to-RGB traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("Cmyk.ToRgb")]
+    public void CmykOperatorToRgb()
+        => this.cmykOperator.ConvertToRgbInPlace(this.CreateOperatorValues(4));
+
+    /// <summary>
+    /// Runs the replaced CMYK RGB-to-component traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("Cmyk.FromRgb")]
+    public void CmykLegacyFromRgb()
+        => this.cmykLegacy.ConvertFromRgb(this.CreateLegacyValues(4), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the shared CMYK RGB-to-component traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("Cmyk.FromRgb")]
+    public void CmykOperatorFromRgb()
+        => this.cmykOperator.ConvertFromRgb(this.CreateOperatorValues(4), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the replaced YCbCr component-to-RGB traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("YCbCr.ToRgb")]
+    public void YCbCrLegacyToRgb()
+        => this.yCbCrLegacy.ConvertToRgbInPlace(this.CreateLegacyValues(3));
+
+    /// <summary>
+    /// Runs the shared YCbCr component-to-RGB traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("YCbCr.ToRgb")]
+    public void YCbCrOperatorToRgb()
+        => this.yCbCrOperator.ConvertToRgbInPlace(this.CreateOperatorValues(3));
+
+    /// <summary>
+    /// Runs the replaced YCbCr RGB-to-component traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("YCbCr.FromRgb")]
+    public void YCbCrLegacyFromRgb()
+        => this.yCbCrLegacy.ConvertFromRgb(this.CreateLegacyValues(3), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the shared YCbCr RGB-to-component traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("YCbCr.FromRgb")]
+    public void YCbCrOperatorFromRgb()
+        => this.yCbCrOperator.ConvertFromRgb(this.CreateOperatorValues(3), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the replaced YCCK component-to-RGB traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("YccK.ToRgb")]
+    public void YccKLegacyToRgb()
+        => this.yccKLegacy.ConvertToRgbInPlace(this.CreateLegacyValues(4));
+
+    /// <summary>
+    /// Runs the shared YCCK component-to-RGB traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("YccK.ToRgb")]
+    public void YccKOperatorToRgb()
+        => this.yccKOperator.ConvertToRgbInPlace(this.CreateOperatorValues(4));
+
+    /// <summary>
+    /// Runs the replaced YCCK RGB-to-component traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("YccK.FromRgb")]
+    public void YccKLegacyFromRgb()
+        => this.yccKLegacy.ConvertFromRgb(this.CreateLegacyValues(4), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the shared YCCK RGB-to-component traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("YccK.FromRgb")]
+    public void YccKOperatorFromRgb()
+        => this.yccKOperator.ConvertFromRgb(this.CreateOperatorValues(4), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the replaced TIFF CMYK component-to-RGB traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("TiffCmyk.ToRgb")]
+    public void TiffCmykLegacyToRgb()
+        => this.tiffCmykLegacy.ConvertToRgbInPlace(this.CreateLegacyValues(4));
+
+    /// <summary>
+    /// Runs the shared TIFF CMYK component-to-RGB traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("TiffCmyk.ToRgb")]
+    public void TiffCmykOperatorToRgb()
+        => this.tiffCmykOperator.ConvertToRgbInPlace(this.CreateOperatorValues(4));
+
+    /// <summary>
+    /// Runs the replaced TIFF CMYK RGB-to-component traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("TiffCmyk.FromRgb")]
+    public void TiffCmykLegacyFromRgb()
+        => this.tiffCmykLegacy.ConvertFromRgb(this.CreateLegacyValues(4), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the shared TIFF CMYK RGB-to-component traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("TiffCmyk.FromRgb")]
+    public void TiffCmykOperatorFromRgb()
+        => this.tiffCmykOperator.ConvertFromRgb(this.CreateOperatorValues(4), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the replaced TIFF YCCK component-to-RGB traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("TiffYccK.ToRgb")]
+    public void TiffYccKLegacyToRgb()
+        => this.tiffYccKLegacy.ConvertToRgbInPlace(this.CreateLegacyValues(4));
+
+    /// <summary>
+    /// Runs the shared TIFF YCCK component-to-RGB traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("TiffYccK.ToRgb")]
+    public void TiffYccKOperatorToRgb()
+        => this.tiffYccKOperator.ConvertToRgbInPlace(this.CreateOperatorValues(4));
+
+    /// <summary>
+    /// Runs the replaced TIFF YCCK RGB-to-component traversal.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("TiffYccK.FromRgb")]
+    public void TiffYccKLegacyFromRgb()
+        => this.tiffYccKLegacy.ConvertFromRgb(this.CreateLegacyValues(4), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Runs the shared TIFF YCCK RGB-to-component traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("TiffYccK.FromRgb")]
+    public void TiffYccKOperatorFromRgb()
+        => this.tiffYccKOperator.ConvertFromRgb(this.CreateOperatorValues(4), this.r, this.g, this.b);
+
+    /// <summary>
+    /// Creates a correctly aliased component view over the legacy planes.
+    /// </summary>
+    /// <param name="componentCount">The number of component planes owned by the color model.</param>
+    /// <returns>The legacy component view.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private JpegColorConverterBase.ComponentValues CreateLegacyValues(int componentCount)
+        => new(
+            componentCount,
+            this.legacyC0,
+            componentCount > 1 ? this.legacyC1 : this.legacyC0,
+            componentCount > 2 ? this.legacyC2 : this.legacyC0,
+            componentCount > 3 ? this.legacyC3 : []);
+
+    /// <summary>
+    /// Creates a correctly aliased component view over the operator planes.
+    /// </summary>
+    /// <param name="componentCount">The number of component planes owned by the color model.</param>
+    /// <returns>The operator component view.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private JpegColorConverterBase.ComponentValues CreateOperatorValues(int componentCount)
+        => new(
+            componentCount,
+            this.operatorC0,
+            componentCount > 1 ? this.operatorC1 : this.operatorC0,
+            componentCount > 2 ? this.operatorC2 : this.operatorC0,
+            componentCount > 3 ? this.operatorC3 : []);
+}

tests/ImageSharp.Benchmarks/Codecs/Jpeg/ColorConversion/YCbCrOperatorAssembly.cs

@@ -0,0 +1,244 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.Intrinsics;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Columns;
+using BenchmarkDotNet.Configs;
+using SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+namespace SixLabors.ImageSharp.Benchmarks.Codecs.Jpeg;
+
+/// <summary>
+/// Exposes every YCbCr operator overload directly to the disassembly diagnoser.
+/// </summary>
+[Config(typeof(Config.Analysis))]
+[GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory)]
+[CategoriesColumn]
+public class YCbCrOperatorAssembly
+{
+    private const float MaximumValue = 255F;
+    private const float HalfValue = 128F;
+    private const float Scale = 1F / MaximumValue;
+
+    private float scalarC0 = 64F;
+    private float scalarC1 = 96F;
+    private float scalarC2 = 160F;
+
+    private readonly Vector128<float> vector128C0 = Vector128.Create(64F);
+    private readonly Vector128<float> vector128C1 = Vector128.Create(96F);
+    private readonly Vector128<float> vector128C2 = Vector128.Create(160F);
+    private readonly Vector128<float> vector128Maximum = Vector128.Create(MaximumValue);
+    private readonly Vector128<float> vector128Half = Vector128.Create(HalfValue);
+    private readonly Vector128<float> vector128Scale = Vector128.Create(Scale);
+
+    private readonly Vector256<float> vector256C0 = Vector256.Create(64F);
+    private readonly Vector256<float> vector256C1 = Vector256.Create(96F);
+    private readonly Vector256<float> vector256C2 = Vector256.Create(160F);
+    private readonly Vector256<float> vector256Maximum = Vector256.Create(MaximumValue);
+    private readonly Vector256<float> vector256Half = Vector256.Create(HalfValue);
+    private readonly Vector256<float> vector256Scale = Vector256.Create(Scale);
+
+    private readonly Vector512<float> vector512C0 = Vector512.Create(64F);
+    private readonly Vector512<float> vector512C1 = Vector512.Create(96F);
+    private readonly Vector512<float> vector512C2 = Vector512.Create(160F);
+    private readonly Vector512<float> vector512Maximum = Vector512.Create(MaximumValue);
+    private readonly Vector512<float> vector512Half = Vector512.Create(HalfValue);
+    private readonly Vector512<float> vector512Scale = Vector512.Create(Scale);
+
+    /// <summary>
+    /// Invokes the scalar JPEG-to-RGB operator.
+    /// </summary>
+    /// <returns>A checksum containing all three converted channels.</returns>
+    [Benchmark]
+    [BenchmarkCategory("ToRgb")]
+    public float ToRgbScalar()
+    {
+        float c0 = this.scalarC0;
+        float c1 = this.scalarC1;
+        float c2 = this.scalarC2;
+
+        JpegColorConverterBase.YCbCrOperator.ConvertToRgb(
+            ref c0,
+            ref c1,
+            ref c2,
+            0,
+            MaximumValue,
+            HalfValue,
+            Scale);
+
+        // Returning the channel sum keeps every output live in the generated assembly.
+        return c0 + c1 + c2;
+    }
+
+    /// <summary>
+    /// Invokes the Vector128 JPEG-to-RGB operator.
+    /// </summary>
+    /// <returns>A checksum containing all three converted channel vectors.</returns>
+    [Benchmark]
+    [BenchmarkCategory("ToRgb")]
+    public Vector128<float> ToRgbVector128()
+    {
+        Vector128<float> c0 = this.vector128C0;
+        Vector128<float> c1 = this.vector128C1;
+        Vector128<float> c2 = this.vector128C2;
+
+        JpegColorConverterBase.YCbCrOperator.ConvertToRgb(
+            ref c0,
+            ref c1,
+            ref c2,
+            default,
+            this.vector128Maximum,
+            this.vector128Half,
+            this.vector128Scale);
+
+        // The vector sum makes all RGB results observable without adding stores to the measured body.
+        return c0 + c1 + c2;
+    }
+
+    /// <summary>
+    /// Invokes the Vector256 JPEG-to-RGB operator.
+    /// </summary>
+    /// <returns>A checksum containing all three converted channel vectors.</returns>
+    [Benchmark]
+    [BenchmarkCategory("ToRgb")]
+    public Vector256<float> ToRgbVector256()
+    {
+        Vector256<float> c0 = this.vector256C0;
+        Vector256<float> c1 = this.vector256C1;
+        Vector256<float> c2 = this.vector256C2;
+
+        JpegColorConverterBase.YCbCrOperator.ConvertToRgb(
+            ref c0,
+            ref c1,
+            ref c2,
+            default,
+            this.vector256Maximum,
+            this.vector256Half,
+            this.vector256Scale);
+
+        // The vector sum makes all RGB results observable without adding stores to the measured body.
+        return c0 + c1 + c2;
+    }
+
+    /// <summary>
+    /// Invokes the Vector512 JPEG-to-RGB operator.
+    /// </summary>
+    /// <returns>A checksum containing all three converted channel vectors.</returns>
+    [Benchmark]
+    [BenchmarkCategory("ToRgb")]
+    public Vector512<float> ToRgbVector512()
+    {
+        Vector512<float> c0 = this.vector512C0;
+        Vector512<float> c1 = this.vector512C1;
+        Vector512<float> c2 = this.vector512C2;
+
+        JpegColorConverterBase.YCbCrOperator.ConvertToRgb(
+            ref c0,
+            ref c1,
+            ref c2,
+            default,
+            this.vector512Maximum,
+            this.vector512Half,
+            this.vector512Scale);
+
+        // The vector sum makes all RGB results observable without adding stores to the measured body.
+        return c0 + c1 + c2;
+    }
+
+    /// <summary>
+    /// Invokes the scalar RGB-to-JPEG operator.
+    /// </summary>
+    /// <returns>A checksum containing all converted components.</returns>
+    [Benchmark]
+    [BenchmarkCategory("FromRgb")]
+    public float FromRgbScalar()
+    {
+        JpegColorConverterBase.YCbCrOperator.ConvertFromRgb(
+            this.scalarC0,
+            this.scalarC1,
+            this.scalarC2,
+            MaximumValue,
+            HalfValue,
+            Scale,
+            out float c0,
+            out float c1,
+            out float c2,
+            out float c3);
+
+        // c3 is deliberately included so a future four-component implementation remains observable.
+        return c0 + c1 + c2 + c3;
+    }
+
+    /// <summary>
+    /// Invokes the Vector128 RGB-to-JPEG operator.
+    /// </summary>
+    /// <returns>A checksum containing all converted component vectors.</returns>
+    [Benchmark]
+    [BenchmarkCategory("FromRgb")]
+    public Vector128<float> FromRgbVector128()
+    {
+        JpegColorConverterBase.YCbCrOperator.ConvertFromRgb(
+            this.vector128C0,
+            this.vector128C1,
+            this.vector128C2,
+            this.vector128Maximum,
+            this.vector128Half,
+            this.vector128Scale,
+            out Vector128<float> c0,
+            out Vector128<float> c1,
+            out Vector128<float> c2,
+            out Vector128<float> c3);
+
+        // Include all planar results in the returned vector so the JIT retains every calculation.
+        return c0 + c1 + c2 + c3;
+    }
+
+    /// <summary>
+    /// Invokes the Vector256 RGB-to-JPEG operator.
+    /// </summary>
+    /// <returns>A checksum containing all converted component vectors.</returns>
+    [Benchmark]
+    [BenchmarkCategory("FromRgb")]
+    public Vector256<float> FromRgbVector256()
+    {
+        JpegColorConverterBase.YCbCrOperator.ConvertFromRgb(
+            this.vector256C0,
+            this.vector256C1,
+            this.vector256C2,
+            this.vector256Maximum,
+            this.vector256Half,
+            this.vector256Scale,
+            out Vector256<float> c0,
+            out Vector256<float> c1,
+            out Vector256<float> c2,
+            out Vector256<float> c3);
+
+        // Include all planar results in the returned vector so the JIT retains every calculation.
+        return c0 + c1 + c2 + c3;
+    }
+
+    /// <summary>
+    /// Invokes the Vector512 RGB-to-JPEG operator.
+    /// </summary>
+    /// <returns>A checksum containing all converted component vectors.</returns>
+    [Benchmark]
+    [BenchmarkCategory("FromRgb")]
+    public Vector512<float> FromRgbVector512()
+    {
+        JpegColorConverterBase.YCbCrOperator.ConvertFromRgb(
+            this.vector512C0,
+            this.vector512C1,
+            this.vector512C2,
+            this.vector512Maximum,
+            this.vector512Half,
+            this.vector512Scale,
+            out Vector512<float> c0,
+            out Vector512<float> c1,
+            out Vector512<float> c2,
+            out Vector512<float> c3);
+
+        // Include all planar results in the returned vector so the JIT retains every calculation.
+        return c0 + c1 + c2 + c3;
+    }
+}

tests/ImageSharp.Benchmarks/Codecs/Jpeg/ColorConversion/YCbCrOperatorComparison.cs

@@ -0,0 +1,127 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Columns;
+using BenchmarkDotNet.Configs;
+using SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+namespace SixLabors.ImageSharp.Benchmarks.Codecs.Jpeg;
+
+/// <summary>
+/// Compares the shared YCbCr operator traversal with the Vector512 implementation it replaces.
+/// </summary>
+[GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory)]
+[CategoriesColumn]
+public class YCbCrOperatorComparison
+{
+    private JpegColorConverterBase.YCbCrVector512 legacy;
+    private JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YCbCrOperator> operatorConverter;
+    private float[] legacyC0;
+    private float[] legacyC1;
+    private float[] legacyC2;
+    private float[] operatorC0;
+    private float[] operatorC1;
+    private float[] operatorC2;
+    private float[] r;
+    private float[] g;
+    private float[] b;
+
+    /// <summary>
+    /// Gets or sets the number of pixels converted by each invocation.
+    /// </summary>
+    [Params(8, 128, 1024)]
+    public int Count { get; set; }
+
+    /// <summary>
+    /// Creates equivalent converter inputs in independent component buffers.
+    /// </summary>
+    [GlobalSetup]
+    public void Setup()
+    {
+        this.legacy = new JpegColorConverterBase.YCbCrVector512(8);
+        this.operatorConverter =
+            new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YCbCrOperator>(8);
+
+        Random random = new(42);
+        this.legacyC0 = CreateRandomValues(this.Count, random);
+        this.legacyC1 = CreateRandomValues(this.Count, random);
+        this.legacyC2 = CreateRandomValues(this.Count, random);
+        this.operatorC0 = this.legacyC0.ToArray();
+        this.operatorC1 = this.legacyC1.ToArray();
+        this.operatorC2 = this.legacyC2.ToArray();
+        this.r = CreateRandomValues(this.Count, random);
+        this.g = CreateRandomValues(this.Count, random);
+        this.b = CreateRandomValues(this.Count, random);
+    }
+
+    /// <summary>
+    /// Converts YCbCr components to RGB using the Vector512 implementation.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("ToRgb")]
+    public void LegacyToRgb()
+    {
+        JpegColorConverterBase.ComponentValues values =
+            new(3, this.legacyC0, this.legacyC1, this.legacyC2, []);
+
+        this.legacy.ConvertToRgbInPlace(values);
+    }
+
+    /// <summary>
+    /// Converts YCbCr components to RGB using the shared operator traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("ToRgb")]
+    public void OperatorToRgb()
+    {
+        JpegColorConverterBase.ComponentValues values =
+            new(3, this.operatorC0, this.operatorC1, this.operatorC2, []);
+
+        this.operatorConverter.ConvertToRgbInPlace(values);
+    }
+
+    /// <summary>
+    /// Converts RGB to YCbCr components using the Vector512 implementation.
+    /// </summary>
+    [Benchmark(Baseline = true)]
+    [BenchmarkCategory("FromRgb")]
+    public void LegacyFromRgb()
+    {
+        JpegColorConverterBase.ComponentValues values =
+            new(3, this.legacyC0, this.legacyC1, this.legacyC2, []);
+
+        this.legacy.ConvertFromRgb(values, this.r, this.g, this.b);
+    }
+
+    /// <summary>
+    /// Converts RGB to YCbCr components using the shared operator traversal.
+    /// </summary>
+    [Benchmark]
+    [BenchmarkCategory("FromRgb")]
+    public void OperatorFromRgb()
+    {
+        JpegColorConverterBase.ComponentValues values =
+            new(3, this.operatorC0, this.operatorC1, this.operatorC2, []);
+
+        this.operatorConverter.ConvertFromRgb(values, this.r, this.g, this.b);
+    }
+
+    /// <summary>
+    /// Creates deterministic sample-domain values for one component plane.
+    /// </summary>
+    /// <param name="length">The number of samples to create.</param>
+    /// <param name="random">The deterministic random source shared by setup.</param>
+    /// <returns>The populated component plane.</returns>
+    private static float[] CreateRandomValues(int length, Random random)
+    {
+        float[] values = new float[length];
+
+        for (int i = 0; i < values.Length; i++)
+        {
+            values[i] = (float)random.NextDouble() * 255F;
+        }
+
+        return values;
+    }
+}

tests/ImageSharp.Tests/Formats/Jpg/JpegColorConverterTests.cs

@@ -2,6 +2,7 @@
 // Licensed under the Six Labors Split License.
 
 using SixLabors.ImageSharp.ColorProfiles;
+using SixLabors.ImageSharp.ColorProfiles.Icc;
 using SixLabors.ImageSharp.Formats.Jpeg.Components;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Tests.ColorProfiles;
@@ -43,6 +44,11 @@ public class JpegColorConverterTests
         Assert.Throws<InvalidImageContentException>(() => JpegColorConverterBase.GetConverter(JpegColorSpace.YCbCr, invalidPrecision));
     }
 
+    /// <summary>
+    /// Verifies that each supported color space and precision resolves to an available converter.
+    /// </summary>
+    /// <param name="colorSpace">The JPEG color space.</param>
+    /// <param name="precision">The JPEG sample precision.</param>
     [Theory]
     [InlineData(JpegColorSpace.Grayscale, 8)]
     [InlineData(JpegColorSpace.Grayscale, 12)]
@@ -54,6 +60,10 @@ public class JpegColorConverterTests
     [InlineData(JpegColorSpace.RGB, 12)]
     [InlineData(JpegColorSpace.YCbCr, 8)]
     [InlineData(JpegColorSpace.YCbCr, 12)]
+    [InlineData(JpegColorSpace.TiffCmyk, 8)]
+    [InlineData(JpegColorSpace.TiffCmyk, 12)]
+    [InlineData(JpegColorSpace.TiffYccK, 8)]
+    [InlineData(JpegColorSpace.TiffYccK, 12)]
     internal void GetConverterReturnsValidConverter(JpegColorSpace colorSpace, int precision)
     {
         JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(colorSpace, precision);
@@ -74,19 +84,8 @@ public class JpegColorConverterTests
         static void RunTest(string arg)
         {
             // arrange
-            Type expectedType = typeof(JpegColorConverterBase.RgbScalar);
+            Type expectedType =
-            if (JpegColorConverterBase.JpegColorConverterVector512.IsSupported)
+                typeof(JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.RgbOperator>);
-            {
-                expectedType = typeof(JpegColorConverterBase.RgbVector512);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector256.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.RgbVector256);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector128.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.RgbVector128);
-            }
 
             // act
             JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(JpegColorSpace.RGB, 8);
@@ -107,19 +106,8 @@ public class JpegColorConverterTests
         static void RunTest(string arg)
         {
             // arrange
-            Type expectedType = typeof(JpegColorConverterBase.GrayScaleScalar);
+            Type expectedType =
-            if (JpegColorConverterBase.JpegColorConverterVector512.IsSupported)
+                typeof(JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.GrayScaleOperator>);
-            {
-                expectedType = typeof(JpegColorConverterBase.GrayScaleVector512);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector256.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.GrayScaleVector256);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector128.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.GrayScaleVector128);
-            }
 
             // act
             JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(JpegColorSpace.Grayscale, 8);
@@ -140,19 +128,8 @@ public class JpegColorConverterTests
         static void RunTest(string arg)
         {
             // arrange
-            Type expectedType = typeof(JpegColorConverterBase.CmykScalar);
+            Type expectedType =
-            if (JpegColorConverterBase.JpegColorConverterVector512.IsSupported)
+                typeof(JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.CmykOperator>);
-            {
-                expectedType = typeof(JpegColorConverterBase.CmykVector512);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector256.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.CmykVector256);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector128.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.CmykVector128);
-            }
 
             // act
             JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(JpegColorSpace.Cmyk, 8);
@@ -173,19 +150,8 @@ public class JpegColorConverterTests
         static void RunTest(string arg)
         {
             // arrange
-            Type expectedType = typeof(JpegColorConverterBase.YCbCrScalar);
+            Type expectedType =
-            if (JpegColorConverterBase.JpegColorConverterVector512.IsSupported)
+                typeof(JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YCbCrOperator>);
-            {
-                expectedType = typeof(JpegColorConverterBase.YCbCrVector512);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector256.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.YCbCrVector256);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector128.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.YCbCrVector128);
-            }
 
             // act
             JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(JpegColorSpace.YCbCr, 8);
@@ -206,19 +172,8 @@ public class JpegColorConverterTests
         static void RunTest(string arg)
         {
             // arrange
-            Type expectedType = typeof(JpegColorConverterBase.YccKScalar);
+            Type expectedType =
-            if (JpegColorConverterBase.JpegColorConverterVector512.IsSupported)
+                typeof(JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YccKOperator>);
-            {
-                expectedType = typeof(JpegColorConverterBase.YccKVector512);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector256.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.YccKVector256);
-            }
-            else if (JpegColorConverterBase.JpegColorConverterVector128.IsSupported)
-            {
-                expectedType = typeof(JpegColorConverterBase.YccKVector128);
-            }
 
             // act
             JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(JpegColorSpace.Ycck, 8);
@@ -229,6 +184,25 @@ public class JpegColorConverterTests
         }
     }
 
+    /// <summary>
+    /// Verifies that TIFF color spaces resolve to their closed shared converter types.
+    /// </summary>
+    /// <param name="colorSpace">The TIFF JPEG color space.</param>
+    /// <param name="expectedType">The expected closed converter type.</param>
+    [Theory]
+    [InlineData(
+        JpegColorSpace.TiffCmyk,
+        typeof(JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.TiffCmykOperator>))]
+    [InlineData(
+        JpegColorSpace.TiffYccK,
+        typeof(JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.TiffYccKOperator>))]
+    internal void GetConverterReturnsCorrectConverterWithTiffColorSpace(JpegColorSpace colorSpace, Type expectedType)
+    {
+        JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(colorSpace, 8);
+
+        Assert.Equal(expectedType, converter.GetType());
+    }
+
     [Theory]
     [InlineData(JpegColorSpace.Grayscale, 1)]
     [InlineData(JpegColorSpace.Ycck, 4)]
@@ -306,6 +280,171 @@ public class JpegColorConverterTests
         new JpegColorConverterBase.YCbCrScalar(8),
         precision: 2);
 
+    /// <summary>
+    /// Verifies YCbCr equivalence around every scalar and SIMD width boundary.
+    /// </summary>
+    /// <param name="length">The number of samples to convert.</param>
+    /// <param name="precision">The JPEG sample precision.</param>
+    [Theory]
+    [InlineData(1, 8)]
+    [InlineData(3, 12)]
+    [InlineData(4, 8)]
+    [InlineData(7, 12)]
+    [InlineData(8, 8)]
+    [InlineData(15, 12)]
+    [InlineData(16, 8)]
+    [InlineData(31, 12)]
+    [InlineData(32, 8)]
+    [InlineData(40, 12)]
+    [InlineData(64, 8)]
+    [InlineData(128, 12)]
+    public void YCbCrOperatorMatchesScalarForAllVectorBoundaries(int length, int precision)
+    {
+        JpegColorConverterBase converter =
+            new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YCbCrOperator>(precision);
+        JpegColorConverterBase baseline = new JpegColorConverterBase.YCbCrScalar(precision);
+
+        ValidateConversionToRgb(converter, baseline, length, 3, precision);
+        ValidateConversionFromRgb(converter, baseline, length, 3, precision);
+    }
+
+    /// <summary>
+    /// Verifies that the YCbCr operator retains scalar behavior when hardware intrinsics are disabled.
+    /// </summary>
+    [Fact]
+    public void YCbCrOperatorMatchesScalarWithoutHardwareIntrinsics()
+        => FeatureTestRunner.RunWithHwIntrinsicsFeature(
+            RunTest,
+            HwIntrinsics.DisableHWIntrinsic);
+
+    /// <summary>
+    /// Verifies converter equivalence around every scalar and SIMD width boundary.
+    /// </summary>
+    /// <param name="colorSpace">The color space under test.</param>
+    /// <param name="componentCount">The number of component planes written by the converter.</param>
+    [Theory]
+    [InlineData(JpegColorSpace.Grayscale, 1)]
+    [InlineData(JpegColorSpace.RGB, 3)]
+    [InlineData(JpegColorSpace.Cmyk, 4)]
+    [InlineData(JpegColorSpace.Ycck, 4)]
+    [InlineData(JpegColorSpace.TiffCmyk, 4)]
+    internal void OperatorsMatchScalarAcrossEveryWidthBoundary(JpegColorSpace colorSpace, int componentCount)
+    {
+        JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(colorSpace, 8);
+        JpegColorConverterBase baseline = colorSpace switch
+        {
+            JpegColorSpace.Grayscale => new JpegColorConverterBase.GrayScaleScalar(8),
+            JpegColorSpace.RGB => new JpegColorConverterBase.RgbScalar(8),
+            JpegColorSpace.Cmyk => new JpegColorConverterBase.CmykScalar(8),
+            JpegColorSpace.Ycck => new JpegColorConverterBase.YccKScalar(8),
+            JpegColorSpace.TiffCmyk => new JpegColorConverterBase.TiffCmykScalar(8),
+            _ => throw new InvalidOperationException(),
+        };
+
+        // These lengths exercise every point immediately below, at, and above the supported SIMD widths.
+        int[] lengths = [1, 3, 4, 7, 8, 15, 16, 31, 32, 40, 64, 128];
+
+        foreach (int length in lengths)
+        {
+            ValidateConversionToRgb(converter, baseline, length, componentCount, 8);
+            ValidateConversionFromRgb(converter, baseline, length, componentCount, 8);
+        }
+    }
+
+    /// <summary>
+    /// Verifies TIFF YCCK decoding around every scalar and SIMD width boundary.
+    /// </summary>
+    /// <param name="precision">The JPEG sample precision.</param>
+    [Theory]
+    [InlineData(8)]
+    [InlineData(12)]
+    public void TiffYccKOperatorToRgbMatchesScalarAcrossEveryWidthBoundary(int precision)
+    {
+        JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(JpegColorSpace.TiffYccK, precision);
+        JpegColorConverterBase baseline = new JpegColorConverterBase.TiffYccKScalar(precision);
+
+        // The combined lengths force scalar, 128-bit, 256-bit, and 512-bit work on capable hardware.
+        int[] lengths = [1, 3, 4, 7, 8, 15, 16, 31, 32, 40, 64, 128];
+
+        foreach (int length in lengths)
+        {
+            ValidateConversionToRgb(converter, baseline, length, 4, precision);
+        }
+    }
+
+    /// <summary>
+    /// Verifies TIFF YCCK encoding against the canonical normalized color-profile conversion.
+    /// </summary>
+    [Fact]
+    public void TiffYccKOperatorFromRgbMatchesColorProfileDefinition()
+    {
+        const int maximumLength = 40;
+        const float maximumValue = 255F;
+        const float halfValue = 128F;
+        const float tolerance = 0.0001F;
+        float[] rSeed = [0, 255, 255, 0, 0, 127, 32, 240, 0, 255, 255, 0, 0, 127, 32, 240, 0, 255, 64, 192];
+        float[] gSeed = [0, 255, 0, 255, 0, 127, 160, 16, 0, 255, 0, 255, 0, 127, 160, 16, 255, 0, 128, 96];
+        float[] bSeed = [0, 255, 0, 0, 255, 127, 224, 80, 255, 0, 255, 0, 0, 127, 224, 80, 0, 255, 192, 32];
+        float[] r = new float[maximumLength];
+        float[] g = new float[maximumLength];
+        float[] b = new float[maximumLength];
+        JpegColorConverterBase converter = JpegColorConverterBase.GetConverter(JpegColorSpace.TiffYccK, 8);
+
+        // Repeating the color set provides enough lanes to exercise every SIMD width and each mixed-width tail.
+        rSeed.CopyTo(r, 0);
+        rSeed.CopyTo(r, rSeed.Length);
+        gSeed.CopyTo(g, 0);
+        gSeed.CopyTo(g, gSeed.Length);
+        bSeed.CopyTo(b, 0);
+        bSeed.CopyTo(b, bSeed.Length);
+
+        // The normalized color-profile implementation is the canonical definition; JPEG stores each result
+        // in the configured integer sample domain.
+        ColorProfileConverter reference = new();
+        int[] lengths = [1, 3, 4, 7, 8, 15, 16, 31, 32, 40];
+
+        foreach (int length in lengths)
+        {
+            float[] y = new float[length];
+            float[] cb = new float[length];
+            float[] cr = new float[length];
+            float[] k = new float[length];
+            JpegColorConverterBase.ComponentValues values = new(4, y, cb, cr, k);
+
+            converter.ConvertFromRgb(values, r.AsSpan(0, length), g.AsSpan(0, length), b.AsSpan(0, length));
+
+            for (int i = 0; i < length; i++)
+            {
+                Rgb rgb = new(r[i] / maximumValue, g[i] / maximumValue, b[i] / maximumValue);
+                YccK expected = reference.Convert<Rgb, YccK>(rgb);
+
+                Assert.Equal(expected.Y * maximumValue, y[i], tolerance);
+
+                // JPEG centers chroma on the integer sample midpoint (128 at 8-bit precision), whereas
+                // the color-profile definition centers normalized chroma exactly on 0.5.
+                Assert.Equal(halfValue + ((expected.Cb - 0.5F) * maximumValue), cb[i], tolerance);
+                Assert.Equal(halfValue + ((expected.Cr - 0.5F) * maximumValue), cr[i], tolerance);
+                Assert.Equal(expected.K * maximumValue, k[i], tolerance);
+            }
+        }
+    }
+
+    /// <summary>
+    /// Runs the YCbCr equivalence check in the feature-test process.
+    /// </summary>
+    /// <param name="arg">The unused feature-test argument.</param>
+    private static void RunTest(string arg)
+    {
+        const int length = 40;
+        const int precision = 8;
+        JpegColorConverterBase converter =
+            new JpegColorConverterBase.JpegColorConverter<JpegColorConverterBase.YCbCrOperator>(precision);
+        JpegColorConverterBase baseline = new JpegColorConverterBase.YCbCrScalar(precision);
+
+        ValidateConversionToRgb(converter, baseline, length, 3, precision);
+        ValidateConversionFromRgb(converter, baseline, length, 3, precision);
+    }
+
     [Theory]
     [MemberData(nameof(Seeds))]
     public void FromCmykBasic(int seed) =>
@@ -736,6 +875,91 @@ public class JpegColorConverterTests
         }
     }
 
+    /// <summary>
+    /// Compares two component planes using an absolute floating-point tolerance.
+    /// </summary>
+    /// <param name="expected">The expected component values.</param>
+    /// <param name="actual">The actual component values.</param>
+    /// <param name="tolerance">The maximum permitted absolute difference.</param>
+    private static void CompareSequenceWithTolerance(Span<float> expected, Span<float> actual, float tolerance)
+    {
+        for (int i = 0; i < expected.Length; i++)
+        {
+            Assert.Equal(expected[i], actual[i], tolerance);
+        }
+    }
+
+    /// <summary>
+    /// Compares component-to-RGB conversion with a scalar reference implementation.
+    /// </summary>
+    /// <param name="converter">The shared converter under test.</param>
+    /// <param name="baseline">The scalar reference converter.</param>
+    /// <param name="length">The number of samples to convert.</param>
+    /// <param name="componentCount">The number of source component planes.</param>
+    /// <param name="precision">The JPEG sample precision.</param>
+    private static void ValidateConversionToRgb(
+        JpegColorConverterBase converter,
+        JpegColorConverterBase baseline,
+        int length,
+        int componentCount,
+        int precision)
+    {
+        JpegColorConverterBase.ComponentValues expected = CreateRandomValues(length, componentCount, precision);
+        JpegColorConverterBase.ComponentValues actual = CreateRandomValues(length, componentCount, precision);
+
+        baseline.ConvertToRgbInPlace(expected);
+        converter.ConvertToRgbInPlace(actual);
+
+        // SIMD multiply-add instructions can differ from the scalar expression by the final rounding bit.
+        CompareSequenceWithTolerance(expected.Component0, actual.Component0, 0.0001F);
+        CompareSequenceWithTolerance(expected.Component1, actual.Component1, 0.0001F);
+        CompareSequenceWithTolerance(expected.Component2, actual.Component2, 0.0001F);
+    }
+
+    /// <summary>
+    /// Compares RGB-to-component conversion with a scalar reference implementation.
+    /// </summary>
+    /// <param name="converter">The shared converter under test.</param>
+    /// <param name="baseline">The scalar reference converter.</param>
+    /// <param name="length">The number of samples to convert.</param>
+    /// <param name="componentCount">The number of destination component planes.</param>
+    /// <param name="precision">The JPEG sample precision.</param>
+    private static void ValidateConversionFromRgb(
+        JpegColorConverterBase converter,
+        JpegColorConverterBase baseline,
+        int length,
+        int componentCount,
+        int precision)
+    {
+        JpegColorConverterBase.ComponentValues expected = CreateRandomValues(length, componentCount, precision);
+        JpegColorConverterBase.ComponentValues actual = CreateRandomValues(length, componentCount, precision);
+        Random random = new(precision);
+        float[] rLane = CreateRandomValues(length, random);
+        float[] gLane = CreateRandomValues(length, random);
+        float[] bLane = CreateRandomValues(length, random);
+
+        baseline.ConvertFromRgb(expected, rLane, gLane, bLane);
+        converter.ConvertFromRgb(actual, rLane, gLane, bLane);
+
+        // The generic traversal must preserve every plane owned by the closed color model.
+        CompareSequenceWithTolerance(expected.Component0, actual.Component0, 2);
+
+        if (componentCount >= 2)
+        {
+            CompareSequenceWithTolerance(expected.Component1, actual.Component1, 2);
+        }
+
+        if (componentCount >= 3)
+        {
+            CompareSequenceWithTolerance(expected.Component2, actual.Component2, 2);
+        }
+
+        if (componentCount >= 4)
+        {
+            CompareSequenceWithTolerance(expected.Component3, actual.Component3, 2);
+        }
+    }
+
     private static void Validate(
         JpegColorSpace colorSpace,
         in JpegColorConverterBase.ComponentValues original,