Fix convert to yuv: missed last uv row when height is uneven

src/ImageSharp/Formats/WebP/Lossy/YuvConversion.cs

@@ -52,23 +52,23 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
                 PixelOperations<TPixel>.Instance.ToRgba32(configuration, rowSpan, rgbaRow0);
                 PixelOperations<TPixel>.Instance.ToRgba32(configuration, nextRowSpan, rgbaRow1);
 
-                rowsHaveAlpha = YuvConversion.CheckNonOpaque(rgbaRow0) && YuvConversion.CheckNonOpaque(rgbaRow1);
+                rowsHaveAlpha = CheckNonOpaque(rgbaRow0) && CheckNonOpaque(rgbaRow1);
 
                 // Downsample U/V planes, two rows at a time.
                 if (!rowsHaveAlpha)
                 {
-                    YuvConversion.AccumulateRgb(rgbaRow0, rgbaRow1, tmpRgbSpan, width);
+                    AccumulateRgb(rgbaRow0, rgbaRow1, tmpRgbSpan, width);
                 }
                 else
                 {
-                    YuvConversion.AccumulateRgba(rgbaRow0, rgbaRow1, tmpRgbSpan, width);
+                    AccumulateRgba(rgbaRow0, rgbaRow1, tmpRgbSpan, width);
                 }
 
-                YuvConversion.ConvertRgbaToUv(tmpRgbSpan, u.Slice(uvRowIndex * uvWidth), v.Slice(uvRowIndex * uvWidth), uvWidth);
+                ConvertRgbaToUv(tmpRgbSpan, u.Slice(uvRowIndex * uvWidth), v.Slice(uvRowIndex * uvWidth), uvWidth);
                 uvRowIndex++;
 
-                YuvConversion.ConvertRgbaToY(rgbaRow0, y.Slice(rowIndex * width), width);
-                YuvConversion.ConvertRgbaToY(rgbaRow1, y.Slice((rowIndex + 1) * width), width);
+                ConvertRgbaToY(rgbaRow0, y.Slice(rowIndex * width), width);
+                ConvertRgbaToY(rgbaRow1, y.Slice((rowIndex + 1) * width), width);
             }
 
             // Extra last row.
@@ -76,14 +76,15 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
             {
                 if (!rowsHaveAlpha)
                 {
-                    YuvConversion.AccumulateRgb(rgbaRow0, rgbaRow0, tmpRgbSpan, width);
+                    AccumulateRgb(rgbaRow0, rgbaRow0, tmpRgbSpan, width);
                 }
                 else
                 {
-                    YuvConversion.AccumulateRgba(rgbaRow0, rgbaRow0, tmpRgbSpan, width);
+                    AccumulateRgba(rgbaRow0, rgbaRow0, tmpRgbSpan, width);
                 }
 
-                YuvConversion.ConvertRgbaToY(rgbaRow0, y.Slice(rowIndex * width), width);
+                ConvertRgbaToY(rgbaRow0, y.Slice(rowIndex * width), width);
+                ConvertRgbaToUv(tmpRgbSpan, u.Slice(uvRowIndex * uvWidth), v.Slice(uvRowIndex * uvWidth), uvWidth);
             }
         }
 

tests/ImageSharp.Tests/Formats/WebP/WebpEncoderTests.cs

@@ -98,15 +98,13 @@ namespace SixLabors.ImageSharp.Tests.Formats.Webp
         }
 
         [Theory]
-        [WithTestPatternImages(187, 221, PixelTypes.Rgba32)]
-        [WithTestPatternImages(100, 118, PixelTypes.Rgba32)]
+        [WithFile(TestPatternOpaque, PixelTypes.Rgba32)]
+        [WithFile(TestPatternOpaqueSmall, PixelTypes.Rgba32)]
         public void Encode_Lossy_WorksWithTestPattern<TPixel>(TestImageProvider<TPixel> provider)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             using Image<TPixel> image = provider.GetImage();
 
-            // Encoding lossy images with transparency is not yet supported, therefor the test image will be made opaque.
-            image.Mutate(img => img.MakeOpaque());
             var encoder = new WebpEncoder() { Lossy = true };
             image.VerifyEncoder(provider, "webp", string.Empty, encoder);
         }

tests/ImageSharp.Tests/TestImages.cs

@@ -504,6 +504,10 @@ namespace SixLabors.ImageSharp.Tests
             // Reference image as png
             public const string Peak = "WebP/peak.png";
 
+            // Test pattern images for testing the encoder.
+            public const string TestPatternOpaque = "WebP/testpattern_opaque.png";
+            public const string TestPatternOpaqueSmall = "WebP/testpattern_opaque_small.png";
+
             public static class Animated
             {
                 public const string Animated1 = "WebP/animated-webp.webp";

tests/Images/Input/WebP/testpattern_opaque.png

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b89449ae398c5b54a120b6b1e6b394e6d5cd58f0a55e5fb86f759fa12dcd325f
+size 1983

tests/Images/Input/WebP/testpattern_opaque_small.png

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:81ef8da0aae89095da92ac82830e0f3de935d62248954e577bf4d573158ffd5f
+size 35660