Optimize several transforms

src/ImageSharp/ColorProfiles/CieXyz.cs

@@ -80,12 +80,8 @@ public readonly struct CieXyz : IProfileConnectingSpace<CieXyz, CieXyz>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool operator !=(CieXyz left, CieXyz right) => !left.Equals(right);
 
-    /// <summary>
-    /// Returns a new <see cref="Vector3"/> representing this instance.
-    /// </summary>
-    /// <returns>The <see cref="Vector3"/>.</returns>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public Vector3 ToVector3() => new(this.X, this.Y, this.Z);
+    internal Vector3 ToVector3() => new(this.X, this.Y, this.Z);
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     internal Vector4 ToVector4()
@@ -203,5 +199,5 @@ public readonly struct CieXyz : IProfileConnectingSpace<CieXyz, CieXyz>
     public bool Equals(CieXyz other)
         => this.AsVector3Unsafe() == other.AsVector3Unsafe();
 
-    private Vector3 AsVector3Unsafe() => Unsafe.As<CieXyz, Vector3>(ref Unsafe.AsRef(in this));
+    internal Vector3 AsVector3Unsafe() => Unsafe.As<CieXyz, Vector3>(ref Unsafe.AsRef(in this));
 }

src/ImageSharp/ColorProfiles/ColorConversionOptions.cs

@@ -14,11 +14,16 @@ namespace SixLabors.ImageSharp.ColorProfiles;
 public class ColorConversionOptions
 {
     private Matrix4x4 adaptationMatrix;
+    private YCbCrMatrix yCbCrMatrix;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="ColorConversionOptions"/> class.
     /// </summary>
-    public ColorConversionOptions() => this.AdaptationMatrix = KnownChromaticAdaptationMatrices.Bradford;
+    public ColorConversionOptions()
+    {
+        this.AdaptationMatrix = KnownChromaticAdaptationMatrices.Bradford;
+        this.YCbCrMatrix = KnownYCbCrMatrices.BT601;
+    }
 
     /// <summary>
     /// Gets the memory allocator.
@@ -48,7 +53,15 @@ public class ColorConversionOptions
     /// <summary>
     /// Gets the YCbCr matrix to used to perform conversions from/to RGB.
     /// </summary>
-    public YCbCrMatrix YCbCrMatrix { get; init; } = KnownYCbCrMatrices.BT601;
+    public YCbCrMatrix YCbCrMatrix
+    {
+        get => this.yCbCrMatrix;
+        init
+        {
+            this.yCbCrMatrix = value;
+            this.TransposedYCbCrMatrix = value.Transpose();
+        }
+    }
 
     /// <summary>
     /// Gets the source ICC profile.
@@ -70,10 +83,12 @@ public class ColorConversionOptions
         init
         {
             this.adaptationMatrix = value;
-            Matrix4x4.Invert(value, out Matrix4x4 inverted);
+            _ = Matrix4x4.Invert(value, out Matrix4x4 inverted);
             this.InverseAdaptationMatrix = inverted;
         }
     }
 
+    internal YCbCrMatrix TransposedYCbCrMatrix { get; private set; }
+
     internal Matrix4x4 InverseAdaptationMatrix { get; private set; }
 }

src/ImageSharp/ColorProfiles/ColorProfileConverterExtensionsIcc.cs

@@ -363,7 +363,7 @@ internal static class ColorProfileConverterExtensionsIcc
         if (targetParams.HasNoPerceptualHandling ||
             (oneProfileHasV2PerceptualAdjustment && targetParams.HasV2PerceptualHandling))
         {
-            Vector3 vector = AdjustPcsToV2BlackPoint(xyz.ToVector3());
+            Vector3 vector = AdjustPcsToV2BlackPoint(xyz.AsVector3Unsafe());
 
             // when using XYZ PCS, negative values are clipped after PCS adjustment (in DemoIccMAX)
             if (targetParams.PcsType == IccColorSpaceType.CieXyz)

src/ImageSharp/ColorProfiles/Icc/Calculators/ColorTrcCalculator.cs

@@ -58,7 +58,7 @@ internal class ColorTrcCalculator : IVector4Calculator
             // when data to PCS, upstream process provides scaled XYZ
             // but input to calculator is descaled XYZ
             // (see DemoMaxICC IccCmm.cpp : CIccXformMatrixTRC::Apply)
-            xyz = new(CieXyz.FromScaledVector4(xyz).ToVector3(), 1);
+            xyz = new(CieXyz.FromScaledVector4(xyz).AsVector3Unsafe(), 1);
             return this.curveCalculator.Calculate(xyz);
         }
     }

src/ImageSharp/ColorProfiles/Lms.cs

@@ -82,13 +82,6 @@ public readonly struct Lms : IColorProfile<Lms, CieXyz>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool operator !=(Lms left, Lms right) => !left.Equals(right);
 
-    /// <summary>
-    /// Returns a new <see cref="Vector3"/> representing this instance.
-    /// </summary>
-    /// <returns>The <see cref="Vector3"/>.</returns>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public Vector3 ToVector3() => new(this.L, this.M, this.S);
-
     /// <inheritdoc/>
     public Vector4 ToScaledVector4()
     {
@@ -134,10 +127,7 @@ public readonly struct Lms : IColorProfile<Lms, CieXyz>
 
     /// <inheritdoc/>
     public static Lms FromProfileConnectingSpace(ColorConversionOptions options, in CieXyz source)
-    {
+        => new(Vector3.Transform(source.AsVector3Unsafe(), options.AdaptationMatrix));
-        Vector3 vector = Vector3.Transform(source.ToVector3(), options.AdaptationMatrix);
-        return new Lms(vector);
-    }
 
     /// <inheritdoc/>
     public static void FromProfileConnectionSpace(ColorConversionOptions options, ReadOnlySpan<CieXyz> source, Span<Lms> destination)
@@ -153,10 +143,7 @@ public readonly struct Lms : IColorProfile<Lms, CieXyz>
 
     /// <inheritdoc/>
     public CieXyz ToProfileConnectingSpace(ColorConversionOptions options)
-    {
+        => new(Vector3.Transform(this.AsVector3Unsafe(), options.InverseAdaptationMatrix));
-        Vector3 vector = Vector3.Transform(this.ToVector3(), options.InverseAdaptationMatrix);
-        return new CieXyz(vector);
-    }
 
     /// <inheritdoc/>
     public static void ToProfileConnectionSpace(ColorConversionOptions options, ReadOnlySpan<Lms> source, Span<CieXyz> destination)

src/ImageSharp/ColorProfiles/Rgb.cs

@@ -128,7 +128,7 @@ public readonly struct Rgb : IProfileConnectingSpace<Rgb, CieXyz>
     public static Rgb FromProfileConnectingSpace(ColorConversionOptions options, in CieXyz source)
     {
         // Convert to linear rgb then compress.
-        Rgb linear = new(Vector3.Transform(source.ToVector3(), GetCieXyzToRgbMatrix(options.TargetRgbWorkingSpace)));
+        Rgb linear = new(Vector3.Transform(source.AsVector3Unsafe(), GetCieXyzToRgbMatrix(options.TargetRgbWorkingSpace)));
         return FromScaledVector4(options.TargetRgbWorkingSpace.Compress(linear.ToScaledVector4()));
     }
 
@@ -141,7 +141,7 @@ public readonly struct Rgb : IProfileConnectingSpace<Rgb, CieXyz>
         for (int i = 0; i < source.Length; i++)
         {
             // Convert to linear rgb then compress.
-            Rgb linear = new(Vector3.Transform(source[i].ToVector3(), matrix));
+            Rgb linear = new(Vector3.Transform(source[i].AsVector3Unsafe(), matrix));
             Vector4 nonlinear = options.TargetRgbWorkingSpace.Compress(linear.ToScaledVector4());
             destination[i] = FromScaledVector4(nonlinear);
         }
@@ -271,7 +271,7 @@ public readonly struct Rgb : IProfileConnectingSpace<Rgb, CieXyz>
 
         Matrix4x4.Invert(xyzMatrix, out Matrix4x4 inverseXyzMatrix);
 
-        Vector3 vector = Vector3.Transform(workingSpace.WhitePoint.ToVector3(), inverseXyzMatrix);
+        Vector3 vector = Vector3.Transform(workingSpace.WhitePoint.AsVector3Unsafe(), inverseXyzMatrix);
 
         // Use transposed Rows/Columns
         return new Matrix4x4

src/ImageSharp/ColorProfiles/VonKriesChromaticAdaptation.cs

@@ -34,9 +34,9 @@ public static class VonKriesChromaticAdaptation
             return new(source.X, source.Y, source.Z);
         }
 
-        Vector3 sourceColorLms = Vector3.Transform(source.ToVector3(), matrix);
+        Vector3 sourceColorLms = Vector3.Transform(source.AsVector3Unsafe(), matrix);
-        Vector3 sourceWhitePointLms = Vector3.Transform(from.ToVector3(), matrix);
+        Vector3 sourceWhitePointLms = Vector3.Transform(from.AsVector3Unsafe(), matrix);
-        Vector3 targetWhitePointLms = Vector3.Transform(to.ToVector3(), matrix);
+        Vector3 targetWhitePointLms = Vector3.Transform(to.AsVector3Unsafe(), matrix);
 
         Vector3 vector = targetWhitePointLms / sourceWhitePointLms;
         Vector3 targetColorLms = Vector3.Multiply(vector, sourceColorLms);
@@ -76,8 +76,8 @@ public static class VonKriesChromaticAdaptation
         ref CieXyz sourceBase = ref MemoryMarshal.GetReference(source);
         ref CieXyz destinationBase = ref MemoryMarshal.GetReference(destination);
 
-        Vector3 sourceWhitePointLms = Vector3.Transform(from.ToVector3(), matrix);
+        Vector3 sourceWhitePointLms = Vector3.Transform(from.AsVector3Unsafe(), matrix);
-        Vector3 targetWhitePointLms = Vector3.Transform(to.ToVector3(), matrix);
+        Vector3 targetWhitePointLms = Vector3.Transform(to.AsVector3Unsafe(), matrix);
 
         Vector3 vector = targetWhitePointLms / sourceWhitePointLms;
 
@@ -86,7 +86,7 @@ public static class VonKriesChromaticAdaptation
             ref CieXyz sp = ref Unsafe.Add(ref sourceBase, i);
             ref CieXyz dp = ref Unsafe.Add(ref destinationBase, i);
 
-            Vector3 sourceColorLms = Vector3.Transform(sp.ToVector3(), matrix);
+            Vector3 sourceColorLms = Vector3.Transform(sp.AsVector3Unsafe(), matrix);
 
             Vector3 targetColorLms = Vector3.Multiply(vector, sourceColorLms);
             dp = new CieXyz(Vector3.Transform(targetColorLms, inverseMatrix));

src/ImageSharp/ColorProfiles/YCbCr.cs

@@ -130,14 +130,10 @@ public readonly struct YCbCr : IColorProfile<YCbCr, Rgb>
     public static YCbCr FromProfileConnectingSpace(ColorConversionOptions options, in Rgb source)
     {
         Vector3 rgb = source.AsVector3Unsafe();
-        Matrix4x4 m = options.YCbCrMatrix.Forward;
+        Matrix4x4 m = options.TransposedYCbCrMatrix.Forward;
-        Vector3 offset = options.YCbCrMatrix.Offset;
+        Vector3 offset = options.TransposedYCbCrMatrix.Offset;
 
-        float y = Vector3.Dot(rgb, new Vector3(m.M11, m.M12, m.M13));
+        return new YCbCr(Vector3.Transform(rgb, m) + offset, true);
-        float cb = Vector3.Dot(rgb, new Vector3(m.M21, m.M22, m.M23));
-        float cr = Vector3.Dot(rgb, new Vector3(m.M31, m.M32, m.M33));
-
-        return new YCbCr(new Vector3(y, cb, cr) + offset, true);
     }
 
     /// <inheritdoc/>
@@ -156,15 +152,11 @@ public readonly struct YCbCr : IColorProfile<YCbCr, Rgb>
     /// <inheritdoc/>
     public Rgb ToProfileConnectingSpace(ColorConversionOptions options)
     {
-        Matrix4x4 m = options.YCbCrMatrix.Inverse;
+        Matrix4x4 m = options.TransposedYCbCrMatrix.Inverse;
-        Vector3 offset = options.YCbCrMatrix.Offset;
+        Vector3 offset = options.TransposedYCbCrMatrix.Offset;
         Vector3 normalized = this.AsVector3Unsafe() - offset;
 
-        float r = Vector3.Dot(normalized, new Vector3(m.M11, m.M12, m.M13));
+        return Rgb.FromScaledVector3(Vector3.Transform(normalized, m));
-        float g = Vector3.Dot(normalized, new Vector3(m.M21, m.M22, m.M23));
-        float b = Vector3.Dot(normalized, new Vector3(m.M31, m.M32, m.M33));
-
-        return Rgb.FromScaledVector3(new Vector3(r, g, b));
     }
 
     /// <inheritdoc/>

src/ImageSharp/ColorProfiles/YcbCrMatrix.cs

@@ -55,4 +55,7 @@ public readonly struct YCbCrMatrix
     /// Gets the chrominance offset vector to apply during encoding (add) or decoding (subtract).
     /// </summary>
     public Vector3 Offset { get; }
+
+    internal YCbCrMatrix Transpose()
+        => new(Matrix4x4.Transpose(this.Forward), Matrix4x4.Transpose(this.Inverse), this.Offset);
 }

src/ImageSharp/ColorProfiles/YccK.cs

@@ -131,23 +131,18 @@ public readonly struct YccK : IColorProfile<YccK, Rgb>
     /// <inheritdoc/>
     public Rgb ToProfileConnectingSpace(ColorConversionOptions options)
     {
-        Matrix4x4 m = options.YCbCrMatrix.Inverse;
+        Matrix4x4 m = options.TransposedYCbCrMatrix.Inverse;
-        Vector3 offset = options.YCbCrMatrix.Offset;
+        Vector3 offset = options.TransposedYCbCrMatrix.Offset;
         Vector3 normalized = this.AsVector3Unsafe() - offset;
 
-        float r = Vector3.Dot(normalized, new Vector3(m.M11, m.M12, m.M13));
+        return Rgb.FromScaledVector3(Vector3.Transform(normalized, m) * (1F - this.K));
-        float g = Vector3.Dot(normalized, new Vector3(m.M21, m.M22, m.M23));
-        float b = Vector3.Dot(normalized, new Vector3(m.M31, m.M32, m.M33));
-
-        Vector3 rgb = new Vector3(r, g, b) * (1F - this.K);
-        return Rgb.FromScaledVector3(rgb);
     }
 
     /// <inheritdoc/>
     public static YccK FromProfileConnectingSpace(ColorConversionOptions options, in Rgb source)
     {
-        Matrix4x4 m = options.YCbCrMatrix.Forward;
+        Matrix4x4 m = options.TransposedYCbCrMatrix.Forward;
-        Vector3 offset = options.YCbCrMatrix.Offset;
+        Vector3 offset = options.TransposedYCbCrMatrix.Offset;
 
         Vector3 rgb = source.AsVector3Unsafe();
         float k = 1F - MathF.Max(rgb.X, MathF.Max(rgb.Y, rgb.Z));
@@ -158,12 +153,7 @@ public readonly struct YccK : IColorProfile<YccK, Rgb>
         }
 
         rgb /= 1F - k;
-
+        return new YccK(new Vector4(Vector3.Transform(rgb, m), k) + new Vector4(offset, 0F));
-        float y = Vector3.Dot(rgb, new Vector3(m.M11, m.M12, m.M13));
-        float cb = Vector3.Dot(rgb, new Vector3(m.M21, m.M22, m.M23));
-        float cr = Vector3.Dot(rgb, new Vector3(m.M31, m.M32, m.M33));
-
-        return new YccK(new Vector4(y, cb, cr, k) + new Vector4(offset, 0F));
     }
 
     /// <inheritdoc/>