From 1d0834ddde712a76b01292222dbfd1755519c74b Mon Sep 17 00:00:00 2001 From: James Jackson-South Date: Sat, 26 Oct 2019 00:34:31 +1100 Subject: [PATCH] Optimize effor diffusion. Fix #757 --- src/ImageSharp/Advanced/AotCompilerTools.cs | 2 +- .../Extensions/DiffuseExtensions.cs | 4 +- .../BinaryErrorDiffusionProcessor{TPixel}.cs | 4 +- .../Processors/Dithering/AtkinsonDiffuser.cs | 12 ++- .../Processors/Dithering/BurksDiffuser.cs | 12 ++- .../Processors/Dithering/ErrorDiffuser.cs | 96 ++++++------------- .../ErrorDiffusionPaletteProcessor{TPixel}.cs | 4 +- .../Dithering/FloydSteinbergDiffuser.cs | 12 ++- .../Processors/Dithering/IErrorDiffuser.cs | 7 +- .../Dithering/JarvisJudiceNinkeDiffuser.cs | 14 +-- .../Processors/Dithering/Sierra2Diffuser.cs | 12 ++- .../Processors/Dithering/Sierra3Diffuser.cs | 14 +-- .../Dithering/SierraLiteDiffuser.cs | 12 ++- .../Dithering/StevensonArceDiffuser.cs | 16 ++-- .../Processors/Dithering/StuckiDiffuser.cs | 14 +-- .../Processors/Dithering/error_diffusion.txt | 3 + .../OctreeFrameQuantizer{TPixel}.cs | 6 +- .../PaletteFrameQuantizer{TPixel}.cs | 6 +- .../Quantization/WuFrameQuantizer{TPixel}.cs | 2 +- .../ImageSharp.Benchmarks/Samplers/Diffuse.cs | 49 ++++++++++ 20 files changed, 168 insertions(+), 133 deletions(-) create mode 100644 tests/ImageSharp.Benchmarks/Samplers/Diffuse.cs diff --git a/src/ImageSharp/Advanced/AotCompilerTools.cs b/src/ImageSharp/Advanced/AotCompilerTools.cs index 1ceba5f90e..5d172d93f7 100644 --- a/src/ImageSharp/Advanced/AotCompilerTools.cs +++ b/src/ImageSharp/Advanced/AotCompilerTools.cs @@ -136,7 +136,7 @@ namespace SixLabors.ImageSharp.Advanced TPixel pixel = default; using (var image = new ImageFrame(Configuration.Default, 1, 1)) { - test.Dither(image, pixel, pixel, 0, 0, 0, 0, 0, 0); + test.Dither(image, pixel, pixel, 0, 0, 0, 0, 0); } } diff --git a/src/ImageSharp/Processing/Extensions/DiffuseExtensions.cs b/src/ImageSharp/Processing/Extensions/DiffuseExtensions.cs index f9a1bdde0e..b721110998 100644 --- a/src/ImageSharp/Processing/Extensions/DiffuseExtensions.cs +++ b/src/ImageSharp/Processing/Extensions/DiffuseExtensions.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using System; @@ -95,4 +95,4 @@ namespace SixLabors.ImageSharp.Processing.Dithering Rectangle rectangle) => source.ApplyProcessor(new ErrorDiffusionPaletteProcessor(diffuser, threshold, palette), rectangle); } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Binarization/BinaryErrorDiffusionProcessor{TPixel}.cs b/src/ImageSharp/Processing/Processors/Binarization/BinaryErrorDiffusionProcessor{TPixel}.cs index 7e3458ae3e..0124575488 100644 --- a/src/ImageSharp/Processing/Processors/Binarization/BinaryErrorDiffusionProcessor{TPixel}.cs +++ b/src/ImageSharp/Processing/Processors/Binarization/BinaryErrorDiffusionProcessor{TPixel}.cs @@ -14,7 +14,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Binarization /// Performs binary threshold filtering against an image using error diffusion. /// /// The pixel format. - internal class BinaryErrorDiffusionProcessor : ImageProcessor + internal sealed class BinaryErrorDiffusionProcessor : ImageProcessor where TPixel : struct, IPixel { private readonly BinaryErrorDiffusionProcessor definition; @@ -76,7 +76,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Binarization } TPixel transformedPixel = luminance >= threshold ? upperColor : lowerColor; - diffuser.Dither(source, sourcePixel, transformedPixel, x, y, startX, startY, endX, endY); + diffuser.Dither(source, sourcePixel, transformedPixel, x, y, startX, endX, endY); } } } diff --git a/src/ImageSharp/Processing/Processors/Dithering/AtkinsonDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/AtkinsonDiffuser.cs index 0461d179ff..f167ac5cb9 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/AtkinsonDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/AtkinsonDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -11,22 +11,24 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class AtkinsonDiffuser : ErrorDiffuser { + private const float Divisor = 8F; + /// /// The diffusion matrix /// private static readonly DenseMatrix AtkinsonMatrix = new float[,] { - { 0, 0, 1, 1 }, - { 1, 1, 1, 0 }, - { 0, 1, 0, 0 } + { 0, 0, 1 / Divisor, 1 / Divisor }, + { 1 / Divisor, 1 / Divisor, 1 / Divisor, 0 }, + { 0, 1 / Divisor, 0, 0 } }; /// /// Initializes a new instance of the class. /// public AtkinsonDiffuser() - : base(AtkinsonMatrix, 8) + : base(AtkinsonMatrix) { } } diff --git a/src/ImageSharp/Processing/Processors/Dithering/BurksDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/BurksDiffuser.cs index 23d4321e96..3c1ff75f4c 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/BurksDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/BurksDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -11,22 +11,24 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class BurksDiffuser : ErrorDiffuser { + private const float Divisor = 32F; + /// /// The diffusion matrix /// private static readonly DenseMatrix BurksMatrix = new float[,] { - { 0, 0, 0, 8, 4 }, - { 2, 4, 8, 4, 2 } + { 0, 0, 0, 8 / Divisor, 4 / Divisor }, + { 2 / Divisor, 4 / Divisor, 8 / Divisor, 4 / Divisor, 2 / Divisor } }; /// /// Initializes a new instance of the class. /// public BurksDiffuser() - : base(BurksMatrix, 32) + : base(BurksMatrix) { } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/ErrorDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/ErrorDiffuser.cs index 1c8156bf51..a6f666c98c 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/ErrorDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/ErrorDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using System; @@ -15,61 +15,32 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public abstract class ErrorDiffuser : IErrorDiffuser { - /// - /// The vector to perform division. - /// - private readonly Vector4 divisorVector; - - /// - /// The matrix width. - /// - private readonly int matrixHeight; - - /// - /// The matrix height. - /// - private readonly int matrixWidth; - - /// - /// The offset at which to start the dithering operation. - /// private readonly int startingOffset; - - /// - /// The diffusion matrix. - /// private readonly DenseMatrix matrix; /// /// Initializes a new instance of the class. /// /// The dithering matrix. - /// The divisor. - internal ErrorDiffuser(in DenseMatrix matrix, byte divisor) + internal ErrorDiffuser(in DenseMatrix matrix) { - Guard.MustBeGreaterThan(divisor, 0, nameof(divisor)); - - this.matrix = matrix; - this.matrixWidth = this.matrix.Columns; - this.matrixHeight = this.matrix.Rows; - this.divisorVector = new Vector4(divisor); - this.startingOffset = 0; - for (int i = 0; i < this.matrixWidth; i++) + + for (int col = 0; col < matrix.Columns; col++) { - // Good to disable here as we are not comparing mathematical output. - // ReSharper disable once CompareOfFloatsByEqualityOperator - if (matrix[0, i] != 0) + if (matrix[0, col] != 0) { - this.startingOffset = (byte)(i - 1); + this.startingOffset = col - 1; break; } } + + this.matrix = matrix; } /// - [MethodImpl(MethodImplOptions.AggressiveInlining)] - public void Dither(ImageFrame image, TPixel source, TPixel transformed, int x, int y, int minX, int minY, int maxX, int maxY) + [MethodImpl(InliningOptions.ShortMethod)] + public void Dither(ImageFrame image, TPixel source, TPixel transformed, int x, int y, int minX, int maxX, int maxY) where TPixel : struct, IPixel { image[x, y] = transformed; @@ -82,45 +53,40 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering // Calculate the error Vector4 error = source.ToVector4() - transformed.ToVector4(); - this.DoDither(image, x, y, minX, minY, maxX, maxY, error); + this.DoDither(image, x, y, minX, maxX, maxY, error); } - [MethodImpl(MethodImplOptions.NoInlining)] - private void DoDither(ImageFrame image, int x, int y, int minX, int minY, int maxX, int maxY, Vector4 error) + [MethodImpl(InliningOptions.ShortMethod)] + private void DoDither(ImageFrame image, int x, int y, int minX, int maxX, int maxY, Vector4 error) where TPixel : struct, IPixel { + int offset = this.startingOffset; + DenseMatrix matrix = this.matrix; + // Loop through and distribute the error amongst neighboring pixels. - for (int row = 0; row < this.matrixHeight; row++) + for (int row = 0, targetY = y + row; row < matrix.Rows && targetY < maxY; row++) { - int matrixY = y + row; - if (matrixY > minY && matrixY < maxY) - { - Span rowSpan = image.GetPixelRowSpan(matrixY); + Span rowSpan = image.GetPixelRowSpan(targetY); - for (int col = 0; col < this.matrixWidth; col++) + for (int col = 0; col < matrix.Columns; col++) + { + int targetX = x + (col - offset); + if (targetX > minX && targetX < maxX) { - int matrixX = x + (col - this.startingOffset); - - if (matrixX > minX && matrixX < maxX) + float coefficient = matrix[row, col]; + if (coefficient == 0) { - float coefficient = this.matrix[row, col]; - - // Good to disable here as we are not comparing mathematical output. - // ReSharper disable once CompareOfFloatsByEqualityOperator - if (coefficient == 0) - { - continue; - } + continue; + } - ref TPixel pixel = ref rowSpan[matrixX]; - var offsetColor = pixel.ToVector4(); + ref TPixel pixel = ref rowSpan[targetX]; + var offsetColor = pixel.ToVector4(); - Vector4 result = ((error * coefficient) / this.divisorVector) + offsetColor; - pixel.FromVector4(result); - } + Vector4 result = (error * coefficient) + offsetColor; + pixel.FromVector4(result); } } } } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/ErrorDiffusionPaletteProcessor{TPixel}.cs b/src/ImageSharp/Processing/Processors/Dithering/ErrorDiffusionPaletteProcessor{TPixel}.cs index 557a31c336..a14a191c69 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/ErrorDiffusionPaletteProcessor{TPixel}.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/ErrorDiffusionPaletteProcessor{TPixel}.cs @@ -13,7 +13,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// An that dithers an image using error diffusion. /// /// The pixel format. - internal class ErrorDiffusionPaletteProcessor : PaletteDitherProcessor + internal sealed class ErrorDiffusionPaletteProcessor : PaletteDitherProcessor where TPixel : struct, IPixel { /// @@ -79,7 +79,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering } TPixel transformedPixel = luminance >= threshold ? pair.Second : pair.First; - this.Definition.Diffuser.Dither(source, sourcePixel, transformedPixel, x, y, startX, startY, endX, endY); + this.Definition.Diffuser.Dither(source, sourcePixel, transformedPixel, x, y, startX, endX, endY); } } } diff --git a/src/ImageSharp/Processing/Processors/Dithering/FloydSteinbergDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/FloydSteinbergDiffuser.cs index 78a28a693a..ca0e3c647e 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/FloydSteinbergDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/FloydSteinbergDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -11,22 +11,24 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class FloydSteinbergDiffuser : ErrorDiffuser { + private const float Divisor = 16F; + /// /// The diffusion matrix /// private static readonly DenseMatrix FloydSteinbergMatrix = new float[,] { - { 0, 0, 7 }, - { 3, 5, 1 } + { 0, 0, 7 / Divisor }, + { 3 / Divisor, 5 / Divisor, 1 / Divisor } }; /// /// Initializes a new instance of the class. /// public FloydSteinbergDiffuser() - : base(FloydSteinbergMatrix, 16) + : base(FloydSteinbergMatrix) { } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/IErrorDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/IErrorDiffuser.cs index 5b30c0dc4d..8f4381d308 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/IErrorDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/IErrorDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.PixelFormats; @@ -19,11 +19,10 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// The column index. /// The row index. /// The minimum column value. - /// The minimum row value. /// The maximum column value. /// The maximum row value. /// The pixel format. - void Dither(ImageFrame image, TPixel source, TPixel transformed, int x, int y, int minX, int minY, int maxX, int maxY) + void Dither(ImageFrame image, TPixel source, TPixel transformed, int x, int y, int minX, int maxX, int maxY) where TPixel : struct, IPixel; } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/JarvisJudiceNinkeDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/JarvisJudiceNinkeDiffuser.cs index 64c8610833..682db83523 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/JarvisJudiceNinkeDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/JarvisJudiceNinkeDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -11,23 +11,25 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class JarvisJudiceNinkeDiffuser : ErrorDiffuser { + private const float Divisor = 48F; + /// /// The diffusion matrix /// private static readonly DenseMatrix JarvisJudiceNinkeMatrix = new float[,] { - { 0, 0, 0, 7, 5 }, - { 3, 5, 7, 5, 3 }, - { 1, 3, 5, 3, 1 } + { 0, 0, 0, 7 / Divisor, 5 / Divisor }, + { 3 / Divisor, 5 / Divisor, 7 / Divisor, 5 / Divisor, 3 / Divisor }, + { 1 / Divisor, 3 / Divisor, 5 / Divisor, 3 / Divisor, 1 / Divisor } }; /// /// Initializes a new instance of the class. /// public JarvisJudiceNinkeDiffuser() - : base(JarvisJudiceNinkeMatrix, 48) + : base(JarvisJudiceNinkeMatrix) { } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/Sierra2Diffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/Sierra2Diffuser.cs index b489f8f28d..03791bff25 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/Sierra2Diffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/Sierra2Diffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -11,22 +11,24 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class Sierra2Diffuser : ErrorDiffuser { + private const float Divisor = 16F; + /// /// The diffusion matrix /// private static readonly DenseMatrix Sierra2Matrix = new float[,] { - { 0, 0, 0, 4, 3 }, - { 1, 2, 3, 2, 1 } + { 0, 0, 0, 4 / Divisor, 3 / Divisor }, + { 1 / Divisor, 2 / Divisor, 3 / Divisor, 2 / Divisor, 1 / Divisor } }; /// /// Initializes a new instance of the class. /// public Sierra2Diffuser() - : base(Sierra2Matrix, 16) + : base(Sierra2Matrix) { } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/Sierra3Diffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/Sierra3Diffuser.cs index 04abc782a6..c7d7acc82f 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/Sierra3Diffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/Sierra3Diffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -11,23 +11,25 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class Sierra3Diffuser : ErrorDiffuser { + private const float Divisor = 32F; + /// /// The diffusion matrix /// private static readonly DenseMatrix Sierra3Matrix = new float[,] { - { 0, 0, 0, 5, 3 }, - { 2, 4, 5, 4, 2 }, - { 0, 2, 3, 2, 0 } + { 0, 0, 0, 5 / Divisor, 3 / Divisor }, + { 2 / Divisor, 4 / Divisor, 5 / Divisor, 4 / Divisor, 2 / Divisor }, + { 0, 2 / Divisor, 3 / Divisor, 2 / Divisor, 0 } }; /// /// Initializes a new instance of the class. /// public Sierra3Diffuser() - : base(Sierra3Matrix, 32) + : base(Sierra3Matrix) { } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/SierraLiteDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/SierraLiteDiffuser.cs index 2ac69cf456..e969f1b70b 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/SierraLiteDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/SierraLiteDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -11,22 +11,24 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class SierraLiteDiffuser : ErrorDiffuser { + private const float Divisor = 4F; + /// /// The diffusion matrix /// private static readonly DenseMatrix SierraLiteMatrix = new float[,] { - { 0, 0, 2 }, - { 1, 1, 0 } + { 0, 0, 2 / Divisor }, + { 1 / Divisor, 1 / Divisor, 0 } }; /// /// Initializes a new instance of the class. /// public SierraLiteDiffuser() - : base(SierraLiteMatrix, 4) + : base(SierraLiteMatrix) { } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/StevensonArceDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/StevensonArceDiffuser.cs index b929a28d30..61727325ab 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/StevensonArceDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/StevensonArceDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -10,24 +10,26 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class StevensonArceDiffuser : ErrorDiffuser { + private const float Divisor = 200F; + /// /// The diffusion matrix /// private static readonly DenseMatrix StevensonArceMatrix = new float[,] { - { 0, 0, 0, 0, 0, 32, 0 }, - { 12, 0, 26, 0, 30, 0, 16 }, - { 0, 12, 0, 26, 0, 12, 0 }, - { 5, 0, 12, 0, 12, 0, 5 } + { 0, 0, 0, 0, 0, 32 / Divisor, 0 }, + { 12 / Divisor, 0, 26 / Divisor, 0, 30 / Divisor, 0, 16 / Divisor }, + { 0, 12 / Divisor, 0, 26 / Divisor, 0, 12 / Divisor, 0 }, + { 5 / Divisor, 0, 12 / Divisor, 0, 12 / Divisor, 0, 5 / Divisor } }; /// /// Initializes a new instance of the class. /// public StevensonArceDiffuser() - : base(StevensonArceMatrix, 200) + : base(StevensonArceMatrix) { } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/StuckiDiffuser.cs b/src/ImageSharp/Processing/Processors/Dithering/StuckiDiffuser.cs index bb3aebc3f5..76203201cc 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/StuckiDiffuser.cs +++ b/src/ImageSharp/Processing/Processors/Dithering/StuckiDiffuser.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using SixLabors.ImageSharp.Primitives; @@ -11,23 +11,25 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering /// public sealed class StuckiDiffuser : ErrorDiffuser { + private const float Divisor = 42F; + /// /// The diffusion matrix /// private static readonly DenseMatrix StuckiMatrix = new float[,] { - { 0, 0, 0, 8, 4 }, - { 2, 4, 8, 4, 2 }, - { 1, 2, 4, 2, 1 } + { 0, 0, 0, 8 / Divisor, 4 / Divisor }, + { 2 / Divisor, 4 / Divisor, 8 / Divisor, 4 / Divisor, 2 / Divisor }, + { 1 / Divisor, 2 / Divisor, 4 / Divisor, 2 / Divisor, 1 / Divisor } }; /// /// Initializes a new instance of the class. /// public StuckiDiffuser() - : base(StuckiMatrix, 42) + : base(StuckiMatrix) { } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Dithering/error_diffusion.txt b/src/ImageSharp/Processing/Processors/Dithering/error_diffusion.txt index ea412f6351..27dea8af17 100644 --- a/src/ImageSharp/Processing/Processors/Dithering/error_diffusion.txt +++ b/src/ImageSharp/Processing/Processors/Dithering/error_diffusion.txt @@ -1,3 +1,6 @@ +Reference: +http://bisqwit.iki.fi/jutut/kuvat/ordered_dither/error_diffusion.txt + List of error diffusion schemes. Quantization error of *current* pixel is added to the pixels diff --git a/src/ImageSharp/Processing/Processors/Quantization/OctreeFrameQuantizer{TPixel}.cs b/src/ImageSharp/Processing/Processors/Quantization/OctreeFrameQuantizer{TPixel}.cs index 85a4d20295..393cb5f602 100644 --- a/src/ImageSharp/Processing/Processors/Quantization/OctreeFrameQuantizer{TPixel}.cs +++ b/src/ImageSharp/Processing/Processors/Quantization/OctreeFrameQuantizer{TPixel}.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using System; @@ -128,7 +128,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Quantization if (this.Dither) { // Apply the dithering matrix. We have to reapply the value now as the original has changed. - this.Diffuser.Dither(source, sourcePixel, transformedPixel, x, y, 0, 0, width, height); + this.Diffuser.Dither(source, sourcePixel, transformedPixel, x, y, 0, width, height); } output[(y * source.Width) + x] = pixelValue; @@ -571,4 +571,4 @@ namespace SixLabors.ImageSharp.Processing.Processors.Quantization } } } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Quantization/PaletteFrameQuantizer{TPixel}.cs b/src/ImageSharp/Processing/Processors/Quantization/PaletteFrameQuantizer{TPixel}.cs index 265c343e68..f774f80be2 100644 --- a/src/ImageSharp/Processing/Processors/Quantization/PaletteFrameQuantizer{TPixel}.cs +++ b/src/ImageSharp/Processing/Processors/Quantization/PaletteFrameQuantizer{TPixel}.cs @@ -1,4 +1,4 @@ -// Copyright (c) Six Labors and contributors. +// Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using System; @@ -76,7 +76,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Quantization if (this.Dither) { // Apply the dithering matrix. We have to reapply the value now as the original has changed. - this.Diffuser.Dither(source, sourcePixel, transformedPixel, x, y, 0, 0, width, height); + this.Diffuser.Dither(source, sourcePixel, transformedPixel, x, y, 0, width, height); } output[(y * source.Width) + x] = pixelValue; @@ -98,4 +98,4 @@ namespace SixLabors.ImageSharp.Processing.Processors.Quantization [MethodImpl(MethodImplOptions.AggressiveInlining)] private byte QuantizePixel(ref TPixel pixel) => this.GetClosestPixel(ref pixel); } -} \ No newline at end of file +} diff --git a/src/ImageSharp/Processing/Processors/Quantization/WuFrameQuantizer{TPixel}.cs b/src/ImageSharp/Processing/Processors/Quantization/WuFrameQuantizer{TPixel}.cs index 87d696dc91..64a5010a8d 100644 --- a/src/ImageSharp/Processing/Processors/Quantization/WuFrameQuantizer{TPixel}.cs +++ b/src/ImageSharp/Processing/Processors/Quantization/WuFrameQuantizer{TPixel}.cs @@ -260,7 +260,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Quantization if (this.Dither) { // Apply the dithering matrix. We have to reapply the value now as the original has changed. - this.Diffuser.Dither(source, sourcePixel, transformedPixel, x, y, 0, 0, width, height); + this.Diffuser.Dither(source, sourcePixel, transformedPixel, x, y, 0, width, height); } output[(y * source.Width) + x] = pixelValue; diff --git a/tests/ImageSharp.Benchmarks/Samplers/Diffuse.cs b/tests/ImageSharp.Benchmarks/Samplers/Diffuse.cs new file mode 100644 index 0000000000..c0a9d2030e --- /dev/null +++ b/tests/ImageSharp.Benchmarks/Samplers/Diffuse.cs @@ -0,0 +1,49 @@ +using BenchmarkDotNet.Attributes; +using SixLabors.ImageSharp.PixelFormats; +using SixLabors.ImageSharp.Processing; +using SixLabors.ImageSharp.Processing.Dithering; +using SixLabors.Primitives; + +namespace SixLabors.ImageSharp.Benchmarks.Samplers +{ + [Config(typeof(Config.ShortClr))] + public class Diffuse + { + [Benchmark] + public Size DoDiffuse() + { + using (var image = new Image(Configuration.Default, 800, 800, Rgba32.BlanchedAlmond)) + { + image.Mutate(x => x.Diffuse()); + + return image.Size(); + } + } + } +} + +// #### 25th October 2019 #### +// +// BenchmarkDotNet=v0.11.5, OS=Windows 10.0.18362 +// Intel Core i7-8650U CPU 1.90GHz(Kaby Lake R), 1 CPU, 8 logical and 4 physical cores +// .NET Core SDK = 3.0.100 +// +// [Host] : .NET Core 2.1.13 (CoreCLR 4.6.28008.01, CoreFX 4.6.28008.01), 64bit RyuJIT +// Clr : .NET Framework 4.7.2 (CLR 4.0.30319.42000), 64bit RyuJIT-v4.8.4018.0 +// Core : .NET Core 2.1.13 (CoreCLR 4.6.28008.01, CoreFX 4.6.28008.01), 64bit RyuJIT +// +// IterationCount=3 LaunchCount=1 WarmupCount=3 +// +// #### Before #### +// +// | Method | Job | Runtime | Mean | Error | StdDev | Gen 0 | Gen 1 | Gen 2 | Allocated | +// |---------- |----- |-------- |----------:|---------:|---------:|------:|------:|------:|----------:| +// | DoDiffuse | Clr | Clr | 129.58 ms | 24.60 ms | 1.349 ms | - | - | - | 6 KB | +// | DoDiffuse | Core | Core | 92.63 ms | 89.78 ms | 4.921 ms | - | - | - | 4.58 KB | +// +// #### After #### +// +// | Method | Job | Runtime | Mean | Error | StdDev | Gen 0 | Gen 1 | Gen 2 | Allocated | +// |---------- |----- |-------- |---------:|---------:|---------:|------:|------:|------:|----------:| +// | DoDiffuse | Clr | Clr | 12.94 ms | 22.48 ms | 1.232 ms | - | - | - | 4.25 KB | +// | DoDiffuse | Core | Core | 10.95 ms | 19.31 ms | 1.058 ms | - | - | - | 4.13 KB |