Merge branch 'master' into webp

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

@@ -6,7 +6,6 @@ using System.Buffers;
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
-using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -96,7 +95,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Quantization
             this.octree.Palletize(paletteSpan, this.maxColors, ref paletteIndex);
 
             // Length of reduced palette + transparency.
-            ReadOnlyMemory<TPixel> result = this.paletteOwner.Memory.Slice(0, Math.Min(paletteIndex + 2, QuantizerConstants.MaxColors));
+            ReadOnlyMemory<TPixel> result = this.paletteOwner.Memory.Slice(0, Math.Min(paletteIndex + 2, this.maxColors));
             this.pixelMap = new EuclideanPixelMap<TPixel>(this.Configuration, result);
 
             this.palette = result;

src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeProcessor.cs

@@ -26,6 +26,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
             this.DestinationHeight = size.Height;
             this.DestinationRectangle = rectangle;
             this.Compand = options.Compand;
+            this.PremultiplyAlpha = options.PremultiplyAlpha;
         }
 
         /// <summary>
@@ -53,6 +54,11 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
         /// </summary>
         public bool Compand { get; }
 
+        /// <summary>
+        /// Gets a value indicating whether to premultiply the alpha (if it exists) during the resize operation.
+        /// </summary>
+        public bool PremultiplyAlpha { get; }
+
         /// <inheritdoc />
         public override ICloningImageProcessor<TPixel> CreatePixelSpecificCloningProcessor<TPixel>(Configuration configuration, Image<TPixel> source, Rectangle sourceRectangle)
             => new ResizeProcessor<TPixel>(configuration, this, source, sourceRectangle);

src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeProcessor{TPixel}.cs

@@ -21,6 +21,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
         private readonly IResampler resampler;
         private readonly Rectangle destinationRectangle;
         private readonly bool compand;
+        private readonly bool premultiplyAlpha;
         private Image<TPixel> destination;
 
         public ResizeProcessor(Configuration configuration, ResizeProcessor definition, Image<TPixel> source, Rectangle sourceRectangle)
@@ -30,6 +31,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
             this.destinationHeight = definition.DestinationHeight;
             this.destinationRectangle = definition.DestinationRectangle;
             this.resampler = definition.Sampler;
+            this.premultiplyAlpha = definition.PremultiplyAlpha;
             this.compand = definition.Compand;
         }
 
@@ -60,6 +62,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
             Rectangle sourceRectangle = this.SourceRectangle;
             Rectangle destinationRectangle = this.destinationRectangle;
             bool compand = this.compand;
+            bool premultiplyAlpha = this.premultiplyAlpha;
 
             // Handle resize dimensions identical to the original
             if (source.Width == destination.Width
@@ -128,7 +131,8 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
                     sourceRectangle,
                     destinationRectangle,
                     interest,
-                    compand);
+                    compand,
+                    premultiplyAlpha);
             }
         }
 
@@ -159,6 +163,18 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
                 in operation);
         }
 
+        private static PixelConversionModifiers GetModifiers(bool compand, bool premultiplyAlpha)
+        {
+            if (premultiplyAlpha)
+            {
+                return PixelConversionModifiers.Premultiply.ApplyCompanding(compand);
+            }
+            else
+            {
+                return PixelConversionModifiers.None.ApplyCompanding(compand);
+            }
+        }
+
         private static void ApplyResizeFrameTransform(
             Configuration configuration,
             ImageFrame<TPixel> source,
@@ -168,10 +184,10 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
             Rectangle sourceRectangle,
             Rectangle destinationRectangle,
             Rectangle interest,
-            bool compand)
+            bool compand,
+            bool premultiplyAlpha)
         {
-            PixelConversionModifiers conversionModifiers =
-                PixelConversionModifiers.Premultiply.ApplyCompanding(compand);
+            PixelConversionModifiers conversionModifiers = GetModifiers(compand, premultiplyAlpha);
 
             Buffer2DRegion<TPixel> sourceRegion = source.PixelBuffer.GetRegion(sourceRectangle);
 

src/ImageSharp/Processing/ResizeOptions.cs

@@ -45,5 +45,11 @@ namespace SixLabors.ImageSharp.Processing
         /// Gets or sets the target rectangle to resize into.
         /// </summary>
         public Rectangle? TargetRectangle { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value indicating whether to premultiply
+        /// the alpha (if it exists) during the resize operation.
+        /// </summary>
+        public bool PremultiplyAlpha { get; set; } = true;
     }
 }

tests/ImageSharp.Tests/Processing/Processors/Transforms/ResizeTests.cs

@@ -216,6 +216,32 @@ namespace SixLabors.ImageSharp.Tests.Processing.Processors.Transforms
                 appendSourceFileOrDescription: false);
         }
 
+        [Theory]
+        [WithFile(TestImages.Png.Kaboom, DefaultPixelType, false)]
+        [WithFile(TestImages.Png.Kaboom, DefaultPixelType, true)]
+        public void Resize_PremultiplyAlpha<TPixel>(TestImageProvider<TPixel> provider, bool premultiplyAlpha)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            string details = premultiplyAlpha ? "On" : "Off";
+
+            provider.RunValidatingProcessorTest(
+                x =>
+                {
+                    var resizeOptions = new ResizeOptions()
+                    {
+                        Size = x.GetCurrentSize() / 2,
+                        Mode = ResizeMode.Crop,
+                        Sampler = KnownResamplers.Bicubic,
+                        Compand = false,
+                        PremultiplyAlpha = premultiplyAlpha
+                    };
+                    x.Resize(resizeOptions);
+                },
+                details,
+                appendPixelTypeToFileName: false,
+                appendSourceFileOrDescription: false);
+        }
+
         [Theory]
         [WithFile(TestImages.Gif.Giphy, DefaultPixelType)]
         public void Resize_IsAppliedToAllFrames<TPixel>(TestImageProvider<TPixel> provider)

tests/ImageSharp.Tests/Quantization/QuantizedImageTests.cs

@@ -110,6 +110,21 @@ namespace SixLabors.ImageSharp.Tests
             }
         }
 
+        // Test case for issue: https://github.com/SixLabors/ImageSharp/issues/1505
+        [Theory]
+        [WithFile(TestImages.Gif.Issues.Issue1505, PixelTypes.Rgba32)]
+        public void Issue1505<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            using (Image<TPixel> image = provider.GetImage())
+            {
+                var octreeQuantizer = new OctreeQuantizer();
+                IQuantizer<TPixel> quantizer = octreeQuantizer.CreatePixelSpecificQuantizer<TPixel>(Configuration.Default, new QuantizerOptions() { MaxColors = 128 });
+                ImageFrame<TPixel> frame = image.Frames[0];
+                quantizer.BuildPaletteAndQuantizeFrame(frame, frame.Bounds());
+            }
+        }
+
         private int GetTransparentIndex<TPixel>(IndexedImageFrame<TPixel> quantized)
             where TPixel : unmanaged, IPixel<TPixel>
         {

tests/ImageSharp.Tests/TestImages.cs

@@ -415,6 +415,7 @@ namespace SixLabors.ImageSharp.Tests
                 public const string BadAppExtLength = "Gif/issues/issue405_badappextlength252.gif";
                 public const string BadAppExtLength_2 = "Gif/issues/issue405_badappextlength252-2.gif";
                 public const string BadDescriptorWidth = "Gif/issues/issue403_baddescriptorwidth.gif";
+                public const string Issue1505 = "Gif/issues/issue1505_argumentoutofrange.png";
             }
 
             public static readonly string[] All = { Rings, Giphy, Cheers, Trans, Kumin, Leo, Ratio4x1, Ratio1x4 };

tests/Images/External

@@ -1 +1 @@
-Subproject commit 8b43d14d21ce9b436af3d12a70d38402cdba176b
+Subproject commit 346070e5ba538f1a3bbafc0ea7367404c5f8c9ab

tests/Images/Input/Gif/issues/issue1505_argumentoutofrange.png

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:bea0faf09782d0d972e72ad94e53b8ca9c823fd3056fc6a97aba8c43105fcd66
+size 102581