Merge branch 'main' into js/gif-fixes

Author: JimBobSquarePants

src/ImageSharp/Processing/Processors/Quantization/EuclideanPixelMap{TPixel}.cs

@@ -149,13 +149,13 @@ private static int DistanceSquared(Rgba32 a, Rgba32 b)
     /// The granularity of the cache has been determined based upon the current
     /// suite of test images and provides the lowest possible memory usage while
     /// providing enough match accuracy.
-    /// Entry count is currently limited to 1185921 entries (2371842 bytes ~2.26MB).
+    /// Entry count is currently limited to 2335905 entries (4671810 bytes ~4.45MB).
     /// </para>
     /// </remarks>
     private unsafe struct ColorDistanceCache : IDisposable
     {
         private const int IndexBits = 5;
-        private const int IndexAlphaBits = 5;
+        private const int IndexAlphaBits = 6;
         private const int IndexCount = (1 << IndexBits) + 1;
         private const int IndexAlphaCount = (1 << IndexAlphaBits) + 1;
         private const int RgbShift = 8 - IndexBits;

tests/ImageSharp.Tests/Formats/Png/PngDecoderTests.cs

@@ -7,6 +7,7 @@
 using SixLabors.ImageSharp.Formats.Png;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Processing.Processors.Quantization;
 using SixLabors.ImageSharp.Tests.TestUtilities;
 using SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison;
 using SixLabors.ImageSharp.Tests.TestUtilities.ReferenceCodecs;
@@ -537,7 +538,6 @@ public void Issue2209_Decode_HasTransparencyIsTrue<TPixel>(TestImageProvider<TPi
         where TPixel : unmanaged, IPixel<TPixel>
     {
         using Image<TPixel> image = provider.GetImage(PngDecoder.Instance);
-        image.DebugSave(provider);
         PngMetadata metadata = image.Metadata.GetPngMetadata();
         Assert.True(metadata.HasTransparency);
     }

tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.cs

@@ -548,6 +548,20 @@ public void EncodeFixesInvalidOptions()
         image.Save(ms, new PngEncoder { ColorType = PngColorType.RgbWithAlpha });
     }
 
+    // https://github.com/SixLabors/ImageSharp/issues/2469
+    [Theory]
+    [WithFile(TestImages.Png.Issue2469, PixelTypes.Rgba32)]
+    public void Issue2469_Quantized_Encode_Artifacts<TPixel>(TestImageProvider<TPixel> provider)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        using Image<TPixel> image = provider.GetImage(PngDecoder.Instance);
+        PngEncoder encoder = new() { BitDepth = PngBitDepth.Bit8, ColorType = PngColorType.Palette };
+
+        string actualOutputFile = provider.Utility.SaveTestOutputFile(image, "png", encoder);
+        using Image<Rgba32> encoded = Image.Load<Rgba32>(actualOutputFile);
+        encoded.CompareToReferenceOutput(ImageComparer.Exact, provider);
+    }
+
     private static void TestPngEncoderCore<TPixel>(
         TestImageProvider<TPixel> provider,
         PngColorType pngColorType,

tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedMemoryPoolTests.Trim.cs

@@ -113,9 +113,15 @@ static void LeakPoolInstance()
         public static readonly bool Is32BitProcess = !Environment.Is64BitProcess;
         private static readonly List<byte[]> PressureArrays = new();
 
-        [ConditionalFact(nameof(Is32BitProcess))]
+        [Fact]
         public static void GC_Collect_OnHighLoad_TrimsEntirePool()
         {
+            if (!Is32BitProcess)
+            {
+                // This test is only relevant for 32-bit processes.
+                return;
+            }
+
             RemoteExecutor.Invoke(RunTest).Dispose();
 
             static void RunTest()

tests/ImageSharp.Tests/TestImages.cs

@@ -129,9 +129,12 @@ public static class Png
         // Issue 2209: https://github.com/SixLabors/ImageSharp/issues/2209
         public const string Issue2209IndexedWithTransparency = "Png/issues/Issue_2209.png";
 
-        // Issue 2259: https://github.com/SixLabors/ImageSharp/issues/2259
+        // Issue 2259: https://github.com/SixLabors/ImageSharp/issues/2469
         public const string Issue2259 = "Png/issues/Issue_2259.png";
 
+        // Issue 2259: https://github.com/SixLabors/ImageSharp/issues/2469
+        public const string Issue2469 = "Png/issues/issue_2469.png";
+
         // Issue 2447: https://github.com/SixLabors/ImageSharp/issues/2447
         public const string Issue2447 = "Png/issues/issue_2447.png";