Add YccK, normalize YCbCr, update tests

Author: JimBobSquarePants

src/ImageSharp/ColorProfiles/Cmyk.cs

@@ -9,6 +9,7 @@ namespace SixLabors.ImageSharp.ColorProfiles;
 
 /// <summary>
 /// Represents an CMYK (cyan, magenta, yellow, keyline) color.
+/// <see href="https://en.wikipedia.org/wiki/CMYK_color_model"/>
 /// </summary>
 [StructLayout(LayoutKind.Sequential)]
 public readonly struct Cmyk : IColorProfile<Cmyk, Rgb>
@@ -130,12 +131,12 @@ public static void FromScaledVector4(ReadOnlySpan<Vector4> source, Span<Cmyk> de
     public static Cmyk FromProfileConnectingSpace(ColorConversionOptions options, in Rgb source)
     {
         // To CMY
-        Vector3 cmy = Vector3.One - source.ToScaledVector3();
+        Vector3 cmy = Vector3.One - source.AsVector3Unsafe();
 
         // To CMYK
         Vector3 k = new(MathF.Min(cmy.X, MathF.Min(cmy.Y, cmy.Z)));
 
-        if (MathF.Abs(k.X - 1F) < Constants.Epsilon)
+        if (k.X >= 1F - Constants.Epsilon)
         {
             return new Cmyk(0, 0, 0, 1F);
         }
@@ -161,7 +162,7 @@ public static void FromProfileConnectionSpace(ColorConversionOptions options, Re
     /// <inheritdoc/>
     public Rgb ToProfileConnectingSpace(ColorConversionOptions options)
     {
-        Vector3 rgb = (Vector3.One - new Vector3(this.C, this.M, this.Y)) * (Vector3.One - new Vector3(this.K));
+        Vector3 rgb = (Vector3.One - new Vector3(this.C, this.M, this.Y)) * (1F - this.K);
         return Rgb.FromScaledVector3(rgb);
     }
 
@@ -171,8 +172,7 @@ public static void ToProfileConnectionSpace(ColorConversionOptions options, Read
         // TODO: We can possibly optimize this by using SIMD
         for (int i = 0; i < source.Length; i++)
         {
-            Cmyk cmyk = source[i];
-            destination[i] = cmyk.ToProfileConnectingSpace(options);
+            destination[i] = source[i].ToProfileConnectingSpace(options);
         }
     }
 

src/ImageSharp/ColorProfiles/ColorConversionOptions.cs

@@ -46,9 +46,9 @@ public class ColorConversionOptions
     public RgbWorkingSpace TargetRgbWorkingSpace { get; init; } = KnownRgbWorkingSpaces.SRgb;
 
     /// <summary>
-    /// Gets the Y (luma) coefficients to use in conversions from RGB.
+    /// Gets the YCbCr matrix to used to perform conversions from/to RGB.
     /// </summary>
-    public Vector3 YCoefficients { get; init; } = KnownYCoefficients.BT709;
+    public YCbCrMatrix YCbCrMatrix { get; init; } = KnownYCbCrMatrices.BT601;
 
     /// <summary>
     /// Gets the source ICC profile.

src/ImageSharp/ColorProfiles/ColorProfileConverterExtensionsIcc.cs

@@ -6,8 +6,8 @@
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.Intrinsics;
+using SixLabors.ImageSharp.ColorProfiles.Conversion.Icc;
 using SixLabors.ImageSharp.ColorProfiles.Icc;
-using SixLabors.ImageSharp.ColorSpaces.Conversion.Icc;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Metadata.Profiles.Icc;
 

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

@@ -322,10 +322,14 @@ private unsafe void Interpolate3d(float* srcPixel, float* destPixel)
         int offset = 0;
         for (int i = 0; i < this.outputCount; i++)
         {
-            float pv = (p[offset + this.n000] * dF0) + (p[offset + this.n001] * dF1) + (p[offset + this.n010] * dF2) + (p[offset + this.n011] * dF3) +
-                       (p[offset + this.n100] * dF4) + (p[offset + this.n101] * dF5) + (p[offset + this.n110] * dF6) + (p[offset + this.n111] * dF7);
-
-            destPixel[i] = pv;
+            destPixel[i] = (float)((p[offset + this.n000] * dF0) +
+                                   (p[offset + this.n001] * dF1) +
+                                   (p[offset + this.n010] * dF2) +
+                                   (p[offset + this.n011] * dF3) +
+                                   (p[offset + this.n100] * dF4) +
+                                   (p[offset + this.n101] * dF5) +
+                                   (p[offset + this.n110] * dF6) +
+                                   (p[offset + this.n111] * dF7));
             offset++;
         }
     }

src/ImageSharp/ColorProfiles/Icc/Calculators/CurveCalculator.CalculationType.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
-namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Icc;
+namespace SixLabors.ImageSharp.ColorProfiles.Conversion.Icc;
 
 internal partial class CurveCalculator
 {

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

@@ -5,7 +5,7 @@
 using SixLabors.ImageSharp.ColorProfiles.Icc.Calculators;
 using SixLabors.ImageSharp.Metadata.Profiles.Icc;
 
-namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Icc;
+namespace SixLabors.ImageSharp.ColorProfiles.Conversion.Icc;
 
 internal partial class CurveCalculator : ISingleCalculator
 {

src/ImageSharp/ColorProfiles/Icc/Calculators/LutABCalculator.CalculationType.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
-namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Icc;
+namespace SixLabors.ImageSharp.ColorProfiles.Conversion.Icc;
 
 internal partial class LutABCalculator
 {

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

@@ -6,7 +6,7 @@
 using SixLabors.ImageSharp.ColorProfiles.Icc.Calculators;
 using SixLabors.ImageSharp.Metadata.Profiles.Icc;
 
-namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Icc;
+namespace SixLabors.ImageSharp.ColorProfiles.Conversion.Icc;
 
 internal partial class LutABCalculator : IVector4Calculator
 {

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

@@ -3,7 +3,7 @@
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
-using SixLabors.ImageSharp.ColorSpaces.Conversion.Icc;
+using SixLabors.ImageSharp.ColorProfiles.Conversion.Icc;
 using SixLabors.ImageSharp.Metadata.Profiles.Icc;
 
 namespace SixLabors.ImageSharp.ColorProfiles.Icc.Calculators;

src/ImageSharp/ColorProfiles/Icc/IccConverterBase.Checks.cs

@@ -4,7 +4,7 @@
 
 using SixLabors.ImageSharp.Metadata.Profiles.Icc;
 
-namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Icc;
+namespace SixLabors.ImageSharp.ColorProfiles.Conversion.Icc;
 
 /// <summary>
 /// Color converter for ICC profiles