diff --git a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromGrayScale.cs b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromGrayScale.cs index 5d7a31a12b..7424145c3b 100644 --- a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromGrayScale.cs +++ b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromGrayScale.cs @@ -3,6 +3,8 @@ using System; using System.Numerics; +using System.Runtime.CompilerServices; +using System.Runtime.InteropServices; namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters { @@ -17,24 +19,17 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters public override void ConvertToRgba(in ComponentValues values, Span result) { - // TODO: We can optimize a lot here with Vector and SRCS.Unsafe()! - ReadOnlySpan yVals = values.Component0; - - var v = new Vector4(0, 0, 0, 1); - var scale = new Vector4(1 / 255F, 1 / 255F, 1 / 255F, 1F); + ref float sBase = ref MemoryMarshal.GetReference(values.Component0); + ref Vector4 dBase = ref MemoryMarshal.GetReference(result); + for (int i = 0; i < result.Length; i++) { - float y = yVals[i]; - - v.X = y; - v.Y = y; - v.Z = y; - + var v = new Vector4(Unsafe.Add(ref sBase, i)); + v.W = 1f; v *= scale; - - result[i] = v; + Unsafe.Add(ref dBase, i) = v; } } }