diff --git a/src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.YCbCrArm.cs b/src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.YCbCrArm.cs
new file mode 100644
index 000000000..4f7cf1ed6
--- /dev/null
+++ b/src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverter.YCbCrArm.cs
@@ -0,0 +1,122 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.Arm;
+using System.Runtime.Intrinsics.X86;
+using static SixLabors.ImageSharp.SimdUtils;
+
+// ReSharper disable ImpureMethodCallOnReadonlyValueField
+namespace SixLabors.ImageSharp.Formats.Jpeg.Components;
+
+internal abstract partial class JpegColorConverterBase
+{
+ internal sealed class YCbCrArm : JpegColorConverterArm
+ {
+ public YCbCrArm(int precision)
+ : base(JpegColorSpace.YCbCr, precision)
+ {
+ }
+
+ ///
+ public override void ConvertToRgbInplace(in ComponentValues values)
+ {
+ ref Vector128 c0Base =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(values.Component0));
+ ref Vector128 c1Base =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(values.Component1));
+ ref Vector128 c2Base =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(values.Component2));
+
+ // Used for the color conversion
+ var chromaOffset = Vector128.Create(-this.HalfValue);
+ var scale = Vector128.Create(1 / this.MaximumValue);
+ var rCrMult = Vector128.Create(YCbCrScalar.RCrMult);
+ var gCbMult = Vector128.Create(-YCbCrScalar.GCbMult);
+ var gCrMult = Vector128.Create(-YCbCrScalar.GCrMult);
+ var bCbMult = Vector128.Create(YCbCrScalar.BCbMult);
+
+ // Walking 8 elements at one step:
+ nuint n = (uint)values.Component0.Length / (uint)Vector128.Count;
+ for (nuint i = 0; i < n; i++)
+ {
+ // y = yVals[i];
+ // cb = cbVals[i] - 128F;
+ // cr = crVals[i] - 128F;
+ ref Vector128 c0 = ref Unsafe.Add(ref c0Base, i);
+ ref Vector128 c1 = ref Unsafe.Add(ref c1Base, i);
+ ref Vector128 c2 = ref Unsafe.Add(ref c2Base, i);
+
+ Vector128 y = c0;
+ Vector128 cb = AdvSimd.Add(c1, chromaOffset);
+ Vector128 cr = AdvSimd.Add(c2, chromaOffset);
+
+ // r = y + (1.402F * cr);
+ // g = y - (0.344136F * cb) - (0.714136F * cr);
+ // b = y + (1.772F * cb);
+ Vector128 r = HwIntrinsics.MultiplyAdd(y, cr, rCrMult);
+ Vector128 g = HwIntrinsics.MultiplyAdd(HwIntrinsics.MultiplyAdd(y, cb, gCbMult), cr, gCrMult);
+ Vector128 b = HwIntrinsics.MultiplyAdd(y, cb, bCbMult);
+
+ r = AdvSimd.Multiply(AdvSimd.RoundToNearest(r), scale);
+ g = AdvSimd.Multiply(AdvSimd.RoundToNearest(g), scale);
+ b = AdvSimd.Multiply(AdvSimd.RoundToNearest(b), scale);
+
+ c0 = r;
+ c1 = g;
+ c2 = b;
+ }
+ }
+
+ ///
+ public override void ConvertFromRgb(in ComponentValues values, Span rLane, Span gLane, Span bLane)
+ {
+ ref Vector128 destY =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(values.Component0));
+ ref Vector128 destCb =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(values.Component1));
+ ref Vector128 destCr =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(values.Component2));
+
+ ref Vector128 srcR =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(rLane));
+ ref Vector128 srcG =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(gLane));
+ ref Vector128 srcB =
+ ref Unsafe.As>(ref MemoryMarshal.GetReference(bLane));
+
+ // Used for the color conversion
+ var chromaOffset = Vector128.Create(this.HalfValue);
+
+ var f0299 = Vector128.Create(0.299f);
+ var f0587 = Vector128.Create(0.587f);
+ var f0114 = Vector128.Create(0.114f);
+ var fn0168736 = Vector128.Create(-0.168736f);
+ var fn0331264 = Vector128.Create(-0.331264f);
+ var fn0418688 = Vector128.Create(-0.418688f);
+ var fn0081312F = Vector128.Create(-0.081312F);
+ var f05 = Vector128.Create(0.5f);
+
+ nuint n = (uint)values.Component0.Length / (uint)Vector128.Count;
+ for (nuint i = 0; i < n; i++)
+ {
+ Vector128 r = Unsafe.Add(ref srcR, i);
+ Vector128 g = Unsafe.Add(ref srcG, i);
+ Vector128 b = Unsafe.Add(ref srcB, i);
+
+ // y = 0 + (0.299 * r) + (0.587 * g) + (0.114 * b)
+ // cb = 128 - (0.168736 * r) - (0.331264 * g) + (0.5 * b)
+ // cr = 128 + (0.5 * r) - (0.418688 * g) - (0.081312 * b)
+ Vector128 y = HwIntrinsics.MultiplyAdd(HwIntrinsics.MultiplyAdd(AdvSimd.Multiply(f0114, b), f0587, g), f0299, r);
+ Vector128 cb = AdvSimd.Add(chromaOffset, HwIntrinsics.MultiplyAdd(HwIntrinsics.MultiplyAdd(AdvSimd.Multiply(f05, b), fn0331264, g), fn0168736, r));
+ Vector128 cr = AdvSimd.Add(chromaOffset, HwIntrinsics.MultiplyAdd(HwIntrinsics.MultiplyAdd(AdvSimd.Multiply(fn0081312F, b), fn0418688, g), f05, r));
+
+ Unsafe.Add(ref destY, i) = y;
+ Unsafe.Add(ref destCb, i) = cb;
+ Unsafe.Add(ref destCr, i) = cr;
+ }
+ }
+ }
+}
diff --git a/src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverterBase.cs b/src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverterBase.cs
index 44b4ed4ec..10d80ddb2 100644
--- a/src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverterBase.cs
+++ b/src/ImageSharp/Formats/Jpeg/Components/ColorConverters/JpegColorConverterBase.cs
@@ -138,6 +138,11 @@ internal abstract partial class JpegColorConverterBase
return new YCbCrAvx(precision);
}
+ if (JpegColorConverterArm.IsSupported)
+ {
+ return new YCbCrArm(precision);
+ }
+
if (JpegColorConverterVector.IsSupported)
{
return new YCbCrVector(precision);
diff --git a/tests/ImageSharp.Tests/Formats/Jpg/JpegColorConverterTests.cs b/tests/ImageSharp.Tests/Formats/Jpg/JpegColorConverterTests.cs
index c71c70c33..fac08ee3d 100644
--- a/tests/ImageSharp.Tests/Formats/Jpg/JpegColorConverterTests.cs
+++ b/tests/ImageSharp.Tests/Formats/Jpg/JpegColorConverterTests.cs
@@ -256,6 +256,23 @@ public class JpegColorConverterTests
new JpegColorConverterBase.YCbCrScalar(8),
precĂsion: 2);
+ [Theory]
+ [MemberData(nameof(Seeds))]
+ public void FromYCbCrArm(int seed) =>
+ this.TestConversionToRgb(new JpegColorConverterBase.YCbCrArm(8),
+ 3,
+ seed,
+ new JpegColorConverterBase.YCbCrScalar(8));
+
+ [Theory]
+ [MemberData(nameof(Seeds))]
+ public void FromRgbToYCbCrArm(int seed) =>
+ this.TestConversionFromRgb(new JpegColorConverterBase.YCbCrArm(8),
+ 3,
+ seed,
+ new JpegColorConverterBase.YCbCrScalar(8),
+ precĂsion: 2);
+
[Theory]
[MemberData(nameof(Seeds))]
public void FromCmykAvx2(int seed) =>