diff --git a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykAvx.cs b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykAvx.cs index 4c89fc6fad..d627f7eafd 100644 --- a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykAvx.cs +++ b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykAvx.cs @@ -30,7 +30,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters ref Unsafe.As>(ref MemoryMarshal.GetReference(values.Component3)); // Used for the color conversion - var scale = Vector256.Create(1 / this.MaximumValue); + var scale = Vector256.Create(1 / (this.MaximumValue * this.MaximumValue)); nint n = values.Component0.Length / Vector256.Count; for (nint i = 0; i < n; i++) @@ -41,9 +41,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters Vector256 k = Unsafe.Add(ref c3Base, i); k = Avx.Multiply(k, scale); - c = Avx.Multiply(Avx.Multiply(c, k), scale); - m = Avx.Multiply(Avx.Multiply(m, k), scale); - y = Avx.Multiply(Avx.Multiply(y, k), scale); + c = Avx.Multiply(c, k); + m = Avx.Multiply(m, k); + y = Avx.Multiply(y, k); } } } diff --git a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykScalar.cs b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykScalar.cs index 057d7846a1..e70aa7cb47 100644 --- a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykScalar.cs +++ b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykScalar.cs @@ -24,17 +24,18 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters Span c2 = values.Component2; Span c3 = values.Component3; - float scale = 1 / maxValue; + float scale = 1 / (maxValue * maxValue); for (int i = 0; i < c0.Length; i++) { float c = c0[i]; float m = c1[i]; float y = c2[i]; - float k = c3[i] / maxValue; + float k = c3[i]; - c0[i] = c * k * scale; - c1[i] = m * k * scale; - c2[i] = y * k * scale; + k *= scale; + c0[i] = c * k; + c1[i] = m * k; + c2[i] = y * k; } } } diff --git a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykVector.cs b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykVector.cs index 9b123547b9..8fd9181409 100644 --- a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykVector.cs +++ b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromCmykVector.cs @@ -27,7 +27,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters ref Vector kBase = ref Unsafe.As>(ref MemoryMarshal.GetReference(values.Component3)); - var scale = new Vector(1 / this.MaximumValue); + var scale = new Vector(1 / (this.MaximumValue * this.MaximumValue)); nint n = values.Component0.Length / Vector.Count; for (nint i = 0; i < n; i++) @@ -35,11 +35,12 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters ref Vector c = ref Unsafe.Add(ref cBase, i); ref Vector m = ref Unsafe.Add(ref mBase, i); ref Vector y = ref Unsafe.Add(ref yBase, i); - Vector k = Unsafe.Add(ref kBase, i) * scale; + Vector k = Unsafe.Add(ref kBase, i); - c = c * k * scale; - m = m * k * scale; - y = y * k * scale; + k *= scale; + c *= k; + m *= k; + y *= k; } }