Made colors equatable; added more tests; small improvements; changed test-data to cover more edge-cases

HPPH.Generators/Features/Colors.cs

@@ -74,6 +74,9 @@ internal class Colors : IGeneratorFeature
                 
                     #region Methods
                 
+                    /// <inheritdoc />
+                    public bool Equals(IColor? other) => (other != null) && (R == other.R) && (G == other.G) && (B == other.B) && (A == other.A);
+                
                     /// <inheritdoc />
                     public override string ToString() => $"[A: {A}, R: {R}, G: {G}, B: {B}]";
                 
@@ -137,6 +140,9 @@ internal class Colors : IGeneratorFeature
                 
                     #region Methods
                 
+                    /// <inheritdoc />
+                    public bool Equals(IColor? other) => (other != null) && (R == other.R) && (G == other.G) && (B == other.B) && (A == other.A);
+                
                     /// <inheritdoc />
                     public override string ToString() => $"[A: {A}, R: {R}, G: {G}, B: {B}]";
                 

HPPH.Reference/PixelHelper.Quantize.cs

@@ -6,8 +6,9 @@ public static partial class ReferencePixelHelper
 {
     #region Methods
 
-    public static IColor[] CreateColorPalette(IImage image, int paletteSize)
-        => CreateColorPalette(image.ToArray(), paletteSize);
+    public static T[] CreateColorPalette<T>(Image<T> image, int paletteSize)
+        where T : unmanaged, IColor
+        => CreateColorPalette<T>(image.ToArray(), paletteSize);
 
     public static T[] CreateColorPalette<T>(RefImage<T> image, int paletteSize)
         where T : unmanaged, IColor
@@ -15,17 +16,20 @@ public static partial class ReferencePixelHelper
 
     public static T[] CreateColorPalette<T>(Span<T> colors, int paletteSize)
         where T : unmanaged, IColor =>
-        CreateColorPalette(colors.ToArray().Cast<IColor>().ToArray(), paletteSize).Select(x => T.Create(x.R, x.G, x.B, x.A)).Cast<T>().ToArray();
+        CreateColorPalette<T>(colors.ToArray().Cast<IColor>().ToArray(), paletteSize).Select(x => T.Create(x.R, x.G, x.B, x.A)).Cast<T>().ToArray();
 
-    private static IColor[] CreateColorPalette(IColor[] colors, int paletteSize)
+    private static IColor[] CreateColorPalette<T>(IColor[] colors, int paletteSize)
+        where T : struct, IColor
     {
+        if (paletteSize == 0) return [];
+
         int splits = BitOperations.Log2((uint)paletteSize);
 
-        List<ColorCube> cubes = [new ColorCube(colors)];
+        HashSet<ColorCube> cubes = [new ColorCube(colors)];
 
         for (int i = 0; i < splits; i++)
         {
-            List<ColorCube> currentCubes = [.. cubes];
+            HashSet<ColorCube> currentCubes = [.. cubes];
             foreach (ColorCube currentCube in currentCubes)
             {
                 currentCube.Split(out ColorCube a, out ColorCube b);
@@ -35,7 +39,7 @@ public static partial class ReferencePixelHelper
             }
         }
 
-        return cubes.Select(c => c.GetAverageColor()).ToArray();
+        return cubes.Select(c => c.GetAverageColor<T>()).ToArray();
     }
 
     #endregion
@@ -53,6 +57,12 @@ internal class ColorCube
 
     internal ColorCube(IList<IColor> colors)
     {
+        if (colors.Count == 0)
+        {
+            _colors = [];
+            return;
+        }
+
         int redRange = colors.Max(c => c.R) - colors.Min(c => c.R);
         int greenRange = colors.Max(c => c.G) - colors.Min(c => c.G);
         int blueRange = colors.Max(c => c.B) - colors.Min(c => c.B);
@@ -77,14 +87,17 @@ internal class ColorCube
         b = new ColorCube(_colors.GetRange(median, _colors.Count - median));
     }
 
-    internal IColor GetAverageColor()
+    internal IColor GetAverageColor<T>()
+        where T : struct, IColor
     {
+        if (_colors.Count == 0) return T.Create(0, 0, 0, 0);
+
         int r = _colors.Sum(x => x.R);
         int g = _colors.Sum(x => x.G);
         int b = _colors.Sum(x => x.B);
         int a = _colors.Sum(x => x.A);
 
-        return new ColorRGBA((byte)(r / _colors.Count),
+        return T.Create((byte)(r / _colors.Count),
                         (byte)(g / _colors.Count),
                         (byte)(b / _colors.Count),
                         (byte)(a / _colors.Count));

HPPH.Test/Colors/MinMaxStructTests.cs

@@ -1,6 +1,4 @@
-using System.Runtime.InteropServices;
-
-namespace HPPH.Test.Colors;
+namespace HPPH.Test.Colors;
 
 [TestClass]
 public class MinMaxStructTests

HPPH.Test/Image/ImageTest.cs

@@ -15,7 +15,7 @@ public class ImageTest
     #region Methods
 
     [TestMethod]
-    public void TestImageCreation()
+    public void ImageCreation()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
 
@@ -28,7 +28,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestImageInnerFull()
+    public void ImageInnerFull()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
         image = image[0, 0, image.Width, image.Height];
@@ -39,7 +39,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestImageEnumerator()
+    public void ImageEnumerator()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
 
@@ -56,7 +56,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestImageInnerPartial()
+    public void ImageInnerPartial()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
         image = image[163, 280, 720, 13];
@@ -70,7 +70,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestImageInnerInnerPartial()
+    public void ImageInnerInnerPartial()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
         image = image[163, 280, 720, 13];
@@ -85,7 +85,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestImageRowIndexer()
+    public void ImageRowIndexer()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
 
@@ -101,7 +101,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestImageRowEnumerator()
+    public void ImageRowEnumerator()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
 
@@ -116,7 +116,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestImageColumnIndexer()
+    public void ImageColumnIndexer()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
 
@@ -132,7 +132,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestImageColumnEnumerator()
+    public void ImageColumnEnumerator()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
 
@@ -147,7 +147,7 @@ public class ImageTest
     }
 
     [TestMethod]
-    public void TestAsRefImage()
+    public void AsRefImage()
     {
         IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
         image = image[163, 280, 720, 13];
@@ -417,6 +417,16 @@ public class ImageTest
 
             y++;
         }
+
+        y = 0;
+        foreach (IImageRow row in (IEnumerable)image.Rows)
+        {
+            int x = 0;
+            foreach (IColor color in (IEnumerable)row)
+                Assert.AreEqual(TestDataHelper.GetColorFromLocation<ColorARGB>(x++, y), color);
+
+            y++;
+        }
     }
 
     [TestMethod]
@@ -509,5 +519,53 @@ public class ImageTest
         }
     }
 
+    [TestMethod]
+    public void InterfaceRowsCopyTo()
+    {
+        IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
+
+        int y = 0;
+        foreach (IImageRow row in image.Rows)
+        {
+            IColor[] colors = new IColor[TEST_WIDTH];
+            byte[] bytes = new byte[TEST_WIDTH * 4];
+            row.CopyTo(colors);
+            row.CopyTo(bytes);
+
+            int x = 0;
+            foreach (IColor color in colors)
+                Assert.AreEqual(TestDataHelper.GetColorFromLocation<ColorARGB>(x++, y), color);
+
+            for (x = 0; x < TEST_WIDTH; x++)
+            {
+                IColor reference = TestDataHelper.GetColorFromLocation<ColorARGB>(x, y);
+
+                Assert.AreEqual(reference.A, bytes[(x * 4) + 0]);
+                Assert.AreEqual(reference.R, bytes[(x * 4) + 1]);
+                Assert.AreEqual(reference.G, bytes[(x * 4) + 2]);
+                Assert.AreEqual(reference.B, bytes[(x * 4) + 3]);
+            }
+
+            y++;
+        }
+    }
+
+    [TestMethod]
+    public void InterfaceRowsToArray()
+    {
+        IImage image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
+
+        int y = 0;
+        foreach (IImageRow row in image.Rows)
+        {
+            IColor[] data = row.ToArray();
+
+            for (int x = 0; x < TEST_WIDTH; x++)
+                Assert.AreEqual(TestDataHelper.GetColorFromLocation<ColorARGB>(x, y), data[x]);
+
+            y++;
+        }
+    }
+
     #endregion
 }

HPPH.Test/Image/RefImageTest.cs

@@ -15,7 +15,7 @@ public class RefImageTest
     #region Methods
 
     [TestMethod]
-    public void TestImageCreation()
+    public void ImageCreation()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
 
@@ -28,7 +28,7 @@ public class RefImageTest
     }
 
     [TestMethod]
-    public void TestImageInnerFull()
+    public void ImageInnerFull()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
         image = image[0, 0, image.Width, image.Height];
@@ -39,7 +39,7 @@ public class RefImageTest
     }
 
     [TestMethod]
-    public void TestImageEnumerator()
+    public void ImageEnumerator()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
 
@@ -58,7 +58,7 @@ public class RefImageTest
     }
 
     [TestMethod]
-    public void TestImageInnerPartial()
+    public void ImageInnerPartial()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
         image = image[163, 280, 720, 13];
@@ -72,7 +72,7 @@ public class RefImageTest
     }
 
     [TestMethod]
-    public void TestImageInnerInnerPartial()
+    public void ImageInnerInnerPartial()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
         image = image[163, 280, 720, 13];
@@ -87,7 +87,7 @@ public class RefImageTest
     }
 
     [TestMethod]
-    public void TestImageRowIndexer()
+    public void ImageRowIndexer()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
 
@@ -103,7 +103,7 @@ public class RefImageTest
     }
 
     [TestMethod]
-    public void TestImageRowEnumerator()
+    public void ImageRowEnumerator()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
 
@@ -118,7 +118,7 @@ public class RefImageTest
     }
 
     [TestMethod]
-    public void TestImageColumnIndexer()
+    public void ImageColumnIndexer()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
 
@@ -134,7 +134,7 @@ public class RefImageTest
     }
 
     [TestMethod]
-    public void TestImageColumnEnumerator()
+    public void ImageColumnEnumerator()
     {
         RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
 
@@ -148,5 +148,57 @@ public class RefImageTest
         }
     }
 
+    [TestMethod]
+    public void ToArray()
+    {
+        RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
+        ColorARGB[] testData = image.ToArray();
+
+        for (int y = 0; y < TEST_HEIGHT; y++)
+            for (int x = 0; x < TEST_WIDTH; x++)
+                Assert.AreEqual(TestDataHelper.GetColorFromLocation<ColorARGB>(x, y), testData[(y * TEST_WIDTH) + x]);
+    }
+
+    [TestMethod]
+    public void CopyTo()
+    {
+        RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
+        ColorARGB[] testData = new ColorARGB[TEST_WIDTH * TEST_HEIGHT];
+        image.CopyTo(testData);
+
+        for (int y = 0; y < TEST_HEIGHT; y++)
+            for (int x = 0; x < TEST_WIDTH; x++)
+                Assert.AreEqual(TestDataHelper.GetColorFromLocation<ColorARGB>(x, y), testData[(y * TEST_WIDTH) + x]);
+    }
+
+    [TestMethod]
+    public void SubImage()
+    {
+        RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
+        RefImage<ColorARGB> subImage = image[10, 20, 100, 200];
+
+        for (int y = 0; y < 200; y++)
+            for (int x = 0; x < 100; x++)
+                Assert.AreEqual(TestDataHelper.GetColorFromLocation<ColorARGB>(10 + x, 20 + y), subImage[x, y]);
+    }
+
+    [TestMethod]
+    public unsafe void Pin()
+    {
+        RefImage<ColorARGB> image = TestDataHelper.CreateTestImage<ColorARGB>(TEST_WIDTH, TEST_HEIGHT).AsRefImage();
+        ColorARGB[] reference = TestDataHelper.GetPixelData<ColorARGB>(TEST_WIDTH, TEST_HEIGHT);
+
+        fixed (byte* ptr = image)
+        {
+            for (int i = 0; i < reference.Length; i++)
+            {
+                Assert.AreEqual(reference[i].A, ptr[(i * 4) + 0]);
+                Assert.AreEqual(reference[i].R, ptr[(i * 4) + 1]);
+                Assert.AreEqual(reference[i].G, ptr[(i * 4) + 2]);
+                Assert.AreEqual(reference[i].B, ptr[(i * 4) + 3]);
+            }
+        }
+    }
+
     #endregion
 }

HPPH.Test/PixelHelper/ConvertTests.cs

@@ -26,10 +26,10 @@ public class ConvertTests
                     ColorRGB reference = referenceData[i];
                     ColorBGR test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }
@@ -56,10 +56,10 @@ public class ConvertTests
                     ColorRGBA reference = referenceData[i];
                     ColorARGB test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }
@@ -86,10 +86,10 @@ public class ConvertTests
                     ColorRGBA reference = referenceData[i];
                     ColorBGRA test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }
@@ -116,10 +116,10 @@ public class ConvertTests
                     ColorRGBA reference = referenceData[i];
                     ColorRGB test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(255, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }
@@ -146,10 +146,10 @@ public class ConvertTests
                     ColorRGBA reference = referenceData[i];
                     ColorBGR test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(255, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }
@@ -176,10 +176,10 @@ public class ConvertTests
                     ColorRGB reference = referenceData[i];
                     ColorRGBA test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }
@@ -206,10 +206,10 @@ public class ConvertTests
                     ColorRGB reference = referenceData[i];
                     ColorARGB test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }
@@ -236,10 +236,10 @@ public class ConvertTests
                     ColorRGB reference = referenceData[i];
                     ColorBGRA test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }
@@ -266,10 +266,10 @@ public class ConvertTests
                     ColorRGB reference = referenceData[i];
                     ColorABGR test = result[i];
 
-                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}");
-                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}");
-                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}");
-                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}");
+                    Assert.AreEqual(reference.R, test.R, $"R differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.G, test.G, $"G differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.B, test.B, $"B differs at index {i}. Image: {image}, skip: {skip}");
+                    Assert.AreEqual(reference.A, test.A, $"A differs at index {i}. Image: {image}, skip: {skip}");
                 }
             }
         }

HPPH.Test/PixelHelper/QuantizeTests.cs

@@ -7,111 +7,196 @@ public class CreateColorPaletteTests
 {
     private static IEnumerable<string> GetTestImages() => Directory.EnumerateFiles(@"..\..\..\..\sample_data", "*.png", SearchOption.AllDirectories);
 
-    [TestMethod]
-    public void CreateColorPaletteReadOnlySpan3ByteSize1()
+    private static int[] Sizes => [0, 1, 2, 16, 64];
+
+    private static readonly Dictionary<string, Dictionary<Type, Dictionary<int, IColor[]>>> _reference = [];
+
+    [ClassInitialize]
+    public static void Initialize(TestContext context)
     {
+        ReadOnlySpan<int> sizes = Sizes;
         foreach (string image in GetTestImages())
         {
-            ColorRGB[] data = ImageHelper.GetColorsFromImage<ColorRGB>(image);
-            Span<ColorRGB> span = data;
+            _reference[image] = [];
 
-            ColorRGB[] reference = [.. ReferencePixelHelper.CreateColorPalette(span, 1).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
-            ColorRGB[] test = [.. span.CreateColorPalette(1).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
-
-            Assert.AreEqual(reference.Length, test.Length, "Palette Size differs");
-
-            for (int i = 0; i < reference.Length; i++)
-                Assert.AreEqual(reference[i], test[i], $"Index {i} differs");
+            Initialize<ColorRGB>(image, sizes);
+            Initialize<ColorBGR>(image, sizes);
+            Initialize<ColorRGBA>(image, sizes);
+            Initialize<ColorBGRA>(image, sizes);
+            Initialize<ColorARGB>(image, sizes);
+            Initialize<ColorABGR>(image, sizes);
         }
     }
 
+    private static void Initialize<T>(string image, ReadOnlySpan<int> sizes)
+        where T : unmanaged, IColor
+    {
+        _reference[image][typeof(T)] = [];
+
+        Image<T> img = ImageHelper.GetImage<T>(image);
+        foreach (int size in sizes)
+            _reference[image][typeof(T)][size] = [.. ReferencePixelHelper.CreateColorPalette(img, size).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+    }
+
     [TestMethod]
-    public void CreateColorPaletteReadOnlySpan3ByteSize4()
+    public void CreateColorPaletteReadOnlySpan()
     {
+        ReadOnlySpan<int> sizes = Sizes;
         foreach (string image in GetTestImages())
         {
-            ColorRGB[] data = ImageHelper.GetColorsFromImage<ColorRGB>(image);
-            Span<ColorRGB> span = data;
+            foreach (int size in sizes)
+            {
+                CreateColorPaletteReadOnlySpan<ColorRGB>(image, size);
+                CreateColorPaletteReadOnlySpan<ColorBGR>(image, size);
+                CreateColorPaletteReadOnlySpan<ColorRGBA>(image, size);
+                CreateColorPaletteReadOnlySpan<ColorBGRA>(image, size);
+                CreateColorPaletteReadOnlySpan<ColorARGB>(image, size);
+                CreateColorPaletteReadOnlySpan<ColorABGR>(image, size);
+            }
+        }
+    }
 
-            ColorRGB[] reference = [.. ReferencePixelHelper.CreateColorPalette(span, 2).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
-            ColorRGB[] test = [.. span.CreateColorPalette(2).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+    private void CreateColorPaletteReadOnlySpan<T>(string image, int size)
+        where T : unmanaged, IColor
+    {
+        T[] data = ImageHelper.GetColorsFromImage<T>(image);
+        ReadOnlySpan<T> span = data;
 
-            Assert.AreEqual(reference.Length, test.Length, "Palette Size differs");
+        T[] test = [.. span.CreateColorPalette(size).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+
+        IColor[] reference = _reference[image][typeof(T)][size];
+        Assert.AreEqual(reference.Length, test.Length, $"Palette Size differs for image {image}, size {size}");
 
         for (int i = 0; i < reference.Length; i++)
-                Assert.AreEqual(reference[i], test[i], $"Index {i} differs");
-        }
+            Assert.AreEqual(reference[i], test[i], $"Index {i} differs for image {image}, size {size}");
     }
 
     [TestMethod]
-    public void CreateColorPaletteReadOnlySpan3ByteSize16()
+    public void CreateColorPaletteSpan()
     {
+        ReadOnlySpan<int> sizes = Sizes;
         foreach (string image in GetTestImages())
         {
-            ColorRGB[] data = ImageHelper.GetColorsFromImage<ColorRGB>(image);
-            Span<ColorRGB> span = data;
+            foreach (int size in sizes)
+            {
+                CreateColorPaletteSpan<ColorRGB>(image, size);
+                CreateColorPaletteSpan<ColorBGR>(image, size);
+                CreateColorPaletteSpan<ColorRGBA>(image, size);
+                CreateColorPaletteSpan<ColorBGRA>(image, size);
+                CreateColorPaletteSpan<ColorARGB>(image, size);
+                CreateColorPaletteSpan<ColorABGR>(image, size);
+            }
+        }
+    }
 
-            ColorRGB[] reference = [.. ReferencePixelHelper.CreateColorPalette(span, 16).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
-            ColorRGB[] test = [.. span.CreateColorPalette(16).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+    private void CreateColorPaletteSpan<T>(string image, int size)
+        where T : unmanaged, IColor
+    {
+        T[] data = ImageHelper.GetColorsFromImage<T>(image);
+        Span<T> span = data;
 
-            Assert.AreEqual(reference.Length, test.Length, "Palette Size differs");
+        T[] test = [.. span.CreateColorPalette(size).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+
+        IColor[] reference = _reference[image][typeof(T)][size];
+        Assert.AreEqual(reference.Length, test.Length, $"Palette Size differs for image {image}, size {size}");
 
         for (int i = 0; i < reference.Length; i++)
-                Assert.AreEqual(reference[i], test[i], $"Index {i} differs");
-        }
+            Assert.AreEqual(reference[i], test[i], $"Index {i} differs for image {image}, size {size}");
     }
 
     [TestMethod]
-    public void CreateColorPaletteReadOnlySpan4ByteSize1()
+    public void CreateColorPaletteImage()
     {
+        ReadOnlySpan<int> sizes = Sizes;
         foreach (string image in GetTestImages())
         {
-            ColorRGBA[] data = ImageHelper.GetColorsFromImage<ColorRGBA>(image);
-            Span<ColorRGBA> span = data;
+            foreach (int size in sizes)
+            {
+                CreateColorPaletteImage<ColorRGB>(image, size);
+                CreateColorPaletteImage<ColorBGR>(image, size);
+                CreateColorPaletteImage<ColorRGBA>(image, size);
+                CreateColorPaletteImage<ColorBGRA>(image, size);
+                CreateColorPaletteImage<ColorARGB>(image, size);
+                CreateColorPaletteImage<ColorABGR>(image, size);
+            }
+        }
+    }
 
-            ColorRGBA[] reference = [.. ReferencePixelHelper.CreateColorPalette(span, 1).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
-            ColorRGBA[] test = [.. span.CreateColorPalette(1).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+    private void CreateColorPaletteImage<T>(string image, int size)
+        where T : struct, IColor
+    {
+        IImage data = ImageHelper.GetImage<T>(image);
 
-            Assert.AreEqual(reference.Length, test.Length, "Palette Size differs");
+        IColor[] test = [.. data.CreateColorPalette(size).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+
+        IColor[] reference = _reference[image][typeof(T)][size];
+        Assert.AreEqual(reference.Length, test.Length, $"Palette Size differs for image {image}, size {size}");
 
         for (int i = 0; i < reference.Length; i++)
-                Assert.AreEqual(reference[i], test[i], $"Index {i} differs");
-        }
+            Assert.AreEqual(reference[i], test[i], $"Index {i} differs for image {image}, size {size}");
     }
 
     [TestMethod]
-    public void CreateColorPaletteReadOnlySpan4ByteSize4()
+    public void CreateColorPaletteGenericImage()
     {
+        ReadOnlySpan<int> sizes = Sizes;
         foreach (string image in GetTestImages())
         {
-            ColorRGBA[] data = ImageHelper.GetColorsFromImage<ColorRGBA>(image);
-            Span<ColorRGBA> span = data;
+            foreach (int size in sizes)
+            {
+                CreateColorPaletteGenericImage<ColorRGB>(image, size);
+                CreateColorPaletteGenericImage<ColorBGR>(image, size);
+                CreateColorPaletteGenericImage<ColorRGBA>(image, size);
+                CreateColorPaletteGenericImage<ColorBGRA>(image, size);
+                CreateColorPaletteGenericImage<ColorARGB>(image, size);
+                CreateColorPaletteGenericImage<ColorABGR>(image, size);
+            }
+        }
+    }
 
-            ColorRGBA[] reference = [.. ReferencePixelHelper.CreateColorPalette(span, 2).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
-            ColorRGBA[] test = [.. span.CreateColorPalette(2).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+    private void CreateColorPaletteGenericImage<T>(string image, int size)
+        where T : unmanaged, IColor
+    {
+        Image<T> data = ImageHelper.GetImage<T>(image);
 
-            Assert.AreEqual(reference.Length, test.Length, "Palette Size differs");
+        T[] test = [.. data.CreateColorPalette(size).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+
+        IColor[] reference = _reference[image][typeof(T)][size];
+        Assert.AreEqual(reference.Length, test.Length, $"Palette Size differs for image {image}, size {size}");
 
         for (int i = 0; i < reference.Length; i++)
-                Assert.AreEqual(reference[i], test[i], $"Index {i} differs");
-        }
+            Assert.AreEqual(reference[i], test[i], $"Index {i} differs for image {image}, size {size}");
     }
 
     [TestMethod]
-    public void CreateColorPaletteReadOnlySpan4ByteSize16()
+    public void CreateColorPaletteRefImage()
     {
+        ReadOnlySpan<int> sizes = Sizes;
         foreach (string image in GetTestImages())
         {
-            ColorRGBA[] data = ImageHelper.GetColorsFromImage<ColorRGBA>(image);
-            Span<ColorRGBA> span = data;
+            foreach (int size in sizes)
+            {
+                CreateColorPaletteRefImage<ColorRGB>(image, size);
+                CreateColorPaletteRefImage<ColorBGR>(image, size);
+                CreateColorPaletteRefImage<ColorRGBA>(image, size);
+                CreateColorPaletteRefImage<ColorBGRA>(image, size);
+                CreateColorPaletteRefImage<ColorARGB>(image, size);
+                CreateColorPaletteRefImage<ColorABGR>(image, size);
+            }
+        }
+    }
 
-            ColorRGBA[] reference = [.. ReferencePixelHelper.CreateColorPalette(span, 16).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
-            ColorRGBA[] test = [.. span.CreateColorPalette(16).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+    private void CreateColorPaletteRefImage<T>(string image, int size)
+        where T : unmanaged, IColor
+    {
+        RefImage<T> data = ImageHelper.GetImage<T>(image).AsRefImage();
 
-            Assert.AreEqual(reference.Length, test.Length, "Palette Size differs");
+        T[] test = [.. data.CreateColorPalette(size).OrderBy(x => x.R).ThenBy(x => x.G).ThenBy(x => x.B).ThenBy(x => x.A)];
+
+        IColor[] reference = _reference[image][typeof(T)][size];
+        Assert.AreEqual(reference.Length, test.Length, $"Palette Size differs for image {image}, size {size}");
 
         for (int i = 0; i < reference.Length; i++)
-                Assert.AreEqual(reference[i], test[i], $"Index {i} differs");
-        }
+            Assert.AreEqual(reference[i], test[i], $"Index {i} differs for image {image}, size {size}");
     }
 }

HPPH/Colors/IColor.cs

@@ -3,7 +3,7 @@
 /// <summary>
 /// Represents a generic color made of 4 bytes (alpha, red, green and blue)
 /// </summary>
-public interface IColor
+public interface IColor : IEquatable<IColor>
 {
     /// <summary>
     /// Gets the red-component of this color.

HPPH/Data/Generic3ByteMinMax.cs

@@ -13,8 +13,4 @@ internal readonly struct Generic3ByteMinMax(byte b1Min, byte b1Max, byte b2Min,
 
     public readonly byte B3Min = b3Min;
     public readonly byte B3Max = b3Max;
-
-    public byte B1Range => (byte)(B1Max - B1Min);
-    public byte B2Range => (byte)(B2Max - B2Min);
-    public byte B3Range => (byte)(B3Max - B3Min);
 }

HPPH/Data/Generic4ByteMinMax.cs

@@ -16,9 +16,4 @@ internal readonly struct Generic4ByteMinMax(byte b1Min, byte b1Max, byte b2Min,
 
     public readonly byte B4Min = b4Min;
     public readonly byte B4Max = b4Max;
-
-    public byte B1Range => (byte)(B1Max - B1Min);
-    public byte B2Range => (byte)(B2Max - B2Min);
-    public byte B3Range => (byte)(B3Max - B3Min);
-    public byte B4Range => (byte)(B4Max - B4Min);
 }

HPPH/Generated/HPPH.Generators/HPPH.Generators.ColorSourceGenerator/ColorABGR.g.cs

@@ -49,6 +49,9 @@ public readonly partial struct ColorABGR(byte a, byte b, byte g, byte r) : IColo
 
     #region Methods
 
+    /// <inheritdoc />
+    public bool Equals(IColor? other) => (other != null) && (R == other.R) && (G == other.G) && (B == other.B) && (A == other.A);
+
     /// <inheritdoc />
     public override string ToString() => $"[A: {A}, R: {R}, G: {G}, B: {B}]";
 

HPPH/Generated/HPPH.Generators/HPPH.Generators.ColorSourceGenerator/ColorARGB.g.cs

@@ -49,6 +49,9 @@ public readonly partial struct ColorARGB(byte a, byte r, byte g, byte b) : IColo
 
     #region Methods
 
+    /// <inheritdoc />
+    public bool Equals(IColor? other) => (other != null) && (R == other.R) && (G == other.G) && (B == other.B) && (A == other.A);
+
     /// <inheritdoc />
     public override string ToString() => $"[A: {A}, R: {R}, G: {G}, B: {B}]";
 

HPPH/Generated/HPPH.Generators/HPPH.Generators.ColorSourceGenerator/ColorBGR.g.cs

@@ -47,6 +47,9 @@ public readonly partial struct ColorBGR(byte b, byte g, byte r): IColor
 
     #region Methods
 
+    /// <inheritdoc />
+    public bool Equals(IColor? other) => (other != null) && (R == other.R) && (G == other.G) && (B == other.B) && (A == other.A);
+
     /// <inheritdoc />
     public override string ToString() => $"[A: {A}, R: {R}, G: {G}, B: {B}]";
 

HPPH/Generated/HPPH.Generators/HPPH.Generators.ColorSourceGenerator/ColorBGRA.g.cs

@@ -49,6 +49,9 @@ public readonly partial struct ColorBGRA(byte b, byte g, byte r, byte a) : IColo
 
     #region Methods
 
+    /// <inheritdoc />
+    public bool Equals(IColor? other) => (other != null) && (R == other.R) && (G == other.G) && (B == other.B) && (A == other.A);
+
     /// <inheritdoc />
     public override string ToString() => $"[A: {A}, R: {R}, G: {G}, B: {B}]";
 

HPPH/Generated/HPPH.Generators/HPPH.Generators.ColorSourceGenerator/ColorRGB.g.cs

@@ -47,6 +47,9 @@ public readonly partial struct ColorRGB(byte r, byte g, byte b): IColor
 
     #region Methods
 
+    /// <inheritdoc />
+    public bool Equals(IColor? other) => (other != null) && (R == other.R) && (G == other.G) && (B == other.B) && (A == other.A);
+
     /// <inheritdoc />
     public override string ToString() => $"[A: {A}, R: {R}, G: {G}, B: {B}]";
 

HPPH/Generated/HPPH.Generators/HPPH.Generators.ColorSourceGenerator/ColorRGBA.g.cs

@@ -49,6 +49,9 @@ public readonly partial struct ColorRGBA(byte r, byte g, byte b, byte a) : IColo
 
     #region Methods
 
+    /// <inheritdoc />
+    public bool Equals(IColor? other) => (other != null) && (R == other.R) && (G == other.G) && (B == other.B) && (A == other.A);
+
     /// <inheritdoc />
     public override string ToString() => $"[A: {A}, R: {R}, G: {G}, B: {B}]";
 

HPPH/Images/Interfaces/IImageRow.cs

@@ -22,6 +22,8 @@ public interface IImageRow : IEnumerable<IColor>
     /// <returns>The <see cref="IColor"/> at the specified location.</returns>
     IColor this[int x] { get; }
 
+    void CopyTo(Span<IColor> destination);
+
     /// <summary>
     /// Copies the contents of this <see cref="IImageRow"/> into a destination <see cref="Span{T}"/> instance.
     /// </summary>

HPPH/PixelHelper.Quantize.cs

@@ -66,6 +66,9 @@ public static partial class PixelHelper
     public static T[] CreateColorPalette<T>(this Span<T> colors, int paletteSize)
         where T : unmanaged, IColor
     {
+        if (paletteSize < 0) throw new ArgumentException("PaletteSize Can't be < 0", nameof(paletteSize));
+        if (paletteSize == 0) return [];
+
         int splits = BitOperations.Log2((uint)paletteSize);
 
         Span<ColorCube<T>> cubes = new ColorCube<T>[1 << splits];