mirror of https://github.com/SixLabors/ImageSharp
James Jackson-South
7 years ago
committed by
GitHub
GitHub
22 changed files with 761 additions and 264 deletions
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System; |
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using System.Runtime.CompilerServices; |
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.ImageSharp.Processing.Processors.Dithering; |
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namespace SixLabors.ImageSharp.Processing.Processors.Quantization |
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{ |
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/// <summary>
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/// A generic palette quantizer.
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/// </summary>
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/// <typeparam name="TPixel">The pixel format.</typeparam>
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public class PaletteQuantizer<TPixel> : IQuantizer |
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where TPixel : struct, IPixel<TPixel> |
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{ |
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/// <summary>
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/// Initializes a new instance of the <see cref="PaletteQuantizer{TPixel}"/> class.
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/// </summary>
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/// <param name="palette">The color palette to use.</param>
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public PaletteQuantizer(TPixel[] palette) |
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: this(palette, true) |
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{ |
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} |
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/// <summary>
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/// Initializes a new instance of the <see cref="PaletteQuantizer{TPixel}"/> class.
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/// </summary>
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/// <param name="palette">The color palette to use.</param>
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/// <param name="dither">Whether to apply dithering to the output image</param>
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public PaletteQuantizer(TPixel[] palette, bool dither) |
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: this(palette, GetDiffuser(dither)) |
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{ |
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} |
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/// <summary>
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/// Initializes a new instance of the <see cref="PaletteQuantizer{TPixel}"/> class.
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/// </summary>
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/// <param name="palette">The color palette to use.</param>
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/// <param name="diffuser">The error diffusion algorithm, if any, to apply to the output image</param>
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public PaletteQuantizer(TPixel[] palette, IErrorDiffuser diffuser) |
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{ |
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Guard.MustBeBetweenOrEqualTo(palette.Length, QuantizerConstants.MinColors, QuantizerConstants.MaxColors, nameof(palette)); |
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this.Palette = palette; |
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this.Diffuser = diffuser; |
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} |
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/// <inheritdoc/>
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public IErrorDiffuser Diffuser { get; } |
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/// <summary>
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/// Gets the palette.
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/// </summary>
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public TPixel[] Palette { get; } |
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/// <summary>
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/// Creates the generic frame quantizer.
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/// </summary>
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/// <param name="configuration">The <see cref="Configuration"/> to configure internal operations.</param>
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/// <returns>The <see cref="IFrameQuantizer{TPixel}"/>.</returns>
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public IFrameQuantizer<TPixel> CreateFrameQuantizer(Configuration configuration) |
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=> ((IQuantizer)this).CreateFrameQuantizer<TPixel>(configuration); |
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/// <summary>
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/// Creates the generic frame quantizer.
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/// </summary>
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/// <param name="configuration">The <see cref="Configuration"/> to configure internal operations.</param>
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/// <param name="maxColors">The maximum number of colors to hold in the color palette.</param>
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/// <returns>The <see cref="IFrameQuantizer{TPixel}"/>.</returns>
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public IFrameQuantizer<TPixel> CreateFrameQuantizer(Configuration configuration, int maxColors) |
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=> ((IQuantizer)this).CreateFrameQuantizer<TPixel>(configuration, maxColors); |
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/// <inheritdoc/>
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IFrameQuantizer<TPixel1> IQuantizer.CreateFrameQuantizer<TPixel1>(Configuration configuration) |
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{ |
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if (!typeof(TPixel).Equals(typeof(TPixel1))) |
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{ |
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throw new InvalidOperationException("Generic method type must be the same as class type."); |
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} |
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TPixel[] paletteRef = this.Palette; |
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return new PaletteFrameQuantizer<TPixel1>(this, Unsafe.As<TPixel[], TPixel1[]>(ref paletteRef)); |
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} |
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/// <inheritdoc/>
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IFrameQuantizer<TPixel1> IQuantizer.CreateFrameQuantizer<TPixel1>(Configuration configuration, int maxColors) |
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{ |
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if (!typeof(TPixel).Equals(typeof(TPixel1))) |
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{ |
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throw new InvalidOperationException("Generic method type must be the same as class type."); |
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} |
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TPixel[] paletteRef = this.Palette; |
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TPixel1[] castPalette = Unsafe.As<TPixel[], TPixel1[]>(ref paletteRef); |
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maxColors = maxColors.Clamp(QuantizerConstants.MinColors, QuantizerConstants.MaxColors); |
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int max = Math.Min(maxColors, castPalette.Length); |
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if (max != castPalette.Length) |
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{ |
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return new PaletteFrameQuantizer<TPixel1>(this, castPalette.AsSpan(0, max).ToArray()); |
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} |
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return new PaletteFrameQuantizer<TPixel1>(this, castPalette); |
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} |
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private static IErrorDiffuser GetDiffuser(bool dither) => dither ? KnownDiffusers.FloydSteinberg : null; |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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namespace SixLabors.ImageSharp.Processing.Processors.Quantization |
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{ |
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/// <summary>
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/// Contains color quantization specific constants.
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/// </summary>
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internal static class QuantizerConstants |
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{ |
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/// <summary>
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/// The minimum number of colors to use when quantizing an image.
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/// </summary>
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public const int MinColors = 1; |
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/// <summary>
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/// The maximum number of colors to use when quantizing an image.
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/// </summary>
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public const int MaxColors = 256; |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.ImageSharp.Processing.Processors.Dithering; |
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namespace SixLabors.ImageSharp.Processing.Processors.Quantization |
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{ |
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/// <summary>
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/// A palette quantizer consisting of web safe colors as defined in the CSS Color Module Level 4.
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/// </summary>
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public class WebSafePaletteQuantizer : PaletteQuantizer |
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{ |
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/// <summary>
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/// Initializes a new instance of the <see cref="WebSafePaletteQuantizer" /> class.
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/// </summary>
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public WebSafePaletteQuantizer() |
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{ |
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} |
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/// <summary>
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/// Initializes a new instance of the <see cref="WebSafePaletteQuantizer" /> class.
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/// </summary>
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/// <param name="dither">Whether to apply dithering to the output image</param>
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public WebSafePaletteQuantizer(bool dither) |
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: base(dither) |
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{ |
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} |
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/// <summary>
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/// Initializes a new instance of the <see cref="WebSafePaletteQuantizer" /> class.
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/// </summary>
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/// <param name="diffuser">The error diffusion algorithm, if any, to apply to the output image</param>
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public WebSafePaletteQuantizer(IErrorDiffuser diffuser) |
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: base(diffuser) |
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{ |
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} |
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/// <inheritdoc />
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public override IFrameQuantizer<TPixel> CreateFrameQuantizer<TPixel>(Configuration configuration) |
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=> this.CreateFrameQuantizer<TPixel>(configuration, NamedColors<TPixel>.WebSafePalette.Length); |
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/// <inheritdoc/>
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public override IFrameQuantizer<TPixel> CreateFrameQuantizer<TPixel>(Configuration configuration, int maxColors) |
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=> this.CreateFrameQuantizer(configuration, NamedColors<TPixel>.WebSafePalette, maxColors); |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.ImageSharp.Processing.Processors.Dithering; |
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namespace SixLabors.ImageSharp.Processing.Processors.Quantization |
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{ |
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/// <summary>
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/// A palette quantizer consisting of colors as defined in the original second edition of Werner’s Nomenclature of Colours 1821.
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/// The hex codes were collected and defined by Nicholas Rougeux <see href="https://www.c82.net/werner"/>
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/// </summary>
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public class WernerPaletteQuantizer : PaletteQuantizer |
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{ |
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/// <summary>
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/// Initializes a new instance of the <see cref="WernerPaletteQuantizer" /> class.
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/// </summary>
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public WernerPaletteQuantizer() |
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{ |
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} |
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/// <summary>
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/// Initializes a new instance of the <see cref="WernerPaletteQuantizer" /> class.
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/// </summary>
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/// <param name="dither">Whether to apply dithering to the output image</param>
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public WernerPaletteQuantizer(bool dither) |
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: base(dither) |
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{ |
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} |
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/// <summary>
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/// Initializes a new instance of the <see cref="WernerPaletteQuantizer" /> class.
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/// </summary>
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/// <param name="diffuser">The error diffusion algorithm, if any, to apply to the output image</param>
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public WernerPaletteQuantizer(IErrorDiffuser diffuser) |
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: base(diffuser) |
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{ |
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} |
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/// <inheritdoc />
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public override IFrameQuantizer<TPixel> CreateFrameQuantizer<TPixel>(Configuration configuration) |
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=> this.CreateFrameQuantizer<TPixel>(configuration, NamedColors<TPixel>.WernerPalette.Length); |
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/// <inheritdoc/>
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public override IFrameQuantizer<TPixel> CreateFrameQuantizer<TPixel>(Configuration configuration, int maxColors) |
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=> this.CreateFrameQuantizer(configuration, NamedColors<TPixel>.WernerPalette, maxColors); |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.ImageSharp.Processing; |
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using SixLabors.ImageSharp.Processing.Processors.Quantization; |
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using Xunit; |
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namespace SixLabors.ImageSharp.Tests.Processing.Processors.Quantization |
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{ |
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public class OctreeQuantizerTests |
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{ |
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[Fact] |
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public void OctreeQuantizerConstructor() |
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{ |
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var quantizer = new OctreeQuantizer(128); |
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Assert.Equal(128, quantizer.MaxColors); |
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Assert.Equal(KnownDiffusers.FloydSteinberg, quantizer.Diffuser); |
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quantizer = new OctreeQuantizer(false); |
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Assert.Equal(QuantizerConstants.MaxColors, quantizer.MaxColors); |
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Assert.Null(quantizer.Diffuser); |
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quantizer = new OctreeQuantizer(KnownDiffusers.Atkinson); |
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Assert.Equal(QuantizerConstants.MaxColors, quantizer.MaxColors); |
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Assert.Equal(KnownDiffusers.Atkinson, quantizer.Diffuser); |
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quantizer = new OctreeQuantizer(KnownDiffusers.Atkinson, 128); |
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Assert.Equal(128, quantizer.MaxColors); |
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Assert.Equal(KnownDiffusers.Atkinson, quantizer.Diffuser); |
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} |
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[Fact] |
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public void OctreeQuantizerCanCreateFrameQuantizer() |
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{ |
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var quantizer = new OctreeQuantizer(); |
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IFrameQuantizer<Rgba32> frameQuantizer = quantizer.CreateFrameQuantizer<Rgba32>(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.True(frameQuantizer.Dither); |
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Assert.Equal(KnownDiffusers.FloydSteinberg, frameQuantizer.Diffuser); |
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quantizer = new OctreeQuantizer(false); |
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frameQuantizer = quantizer.CreateFrameQuantizer<Rgba32>(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.False(frameQuantizer.Dither); |
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Assert.Null(frameQuantizer.Diffuser); |
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quantizer = new OctreeQuantizer(KnownDiffusers.Atkinson); |
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frameQuantizer = quantizer.CreateFrameQuantizer<Rgba32>(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.True(frameQuantizer.Dither); |
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Assert.Equal(KnownDiffusers.Atkinson, frameQuantizer.Diffuser); |
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} |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using System; |
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.ImageSharp.Processing; |
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using SixLabors.ImageSharp.Processing.Processors.Quantization; |
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using Xunit; |
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namespace SixLabors.ImageSharp.Tests.Processing.Processors.Quantization |
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{ |
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public class PaletteQuantizerTests |
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{ |
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private static readonly Rgba32[] Rgb = new Rgba32[] { Rgba32.Red, Rgba32.Green, Rgba32.Blue }; |
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[Fact] |
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public void PaletteQuantizerConstructor() |
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{ |
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var quantizer = new PaletteQuantizer<Rgba32>(Rgb); |
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Assert.Equal(Rgb, quantizer.Palette); |
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Assert.Equal(KnownDiffusers.FloydSteinberg, quantizer.Diffuser); |
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quantizer = new PaletteQuantizer<Rgba32>(Rgb, false); |
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Assert.Equal(Rgb, quantizer.Palette); |
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Assert.Null(quantizer.Diffuser); |
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quantizer = new PaletteQuantizer<Rgba32>(Rgb, KnownDiffusers.Atkinson); |
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Assert.Equal(Rgb, quantizer.Palette); |
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Assert.Equal(KnownDiffusers.Atkinson, quantizer.Diffuser); |
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} |
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[Fact] |
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public void PaletteQuantizerCanCreateFrameQuantizer() |
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{ |
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var quantizer = new PaletteQuantizer<Rgba32>(Rgb); |
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IFrameQuantizer<Rgba32> frameQuantizer = quantizer.CreateFrameQuantizer(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.True(frameQuantizer.Dither); |
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Assert.Equal(KnownDiffusers.FloydSteinberg, frameQuantizer.Diffuser); |
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quantizer = new PaletteQuantizer<Rgba32>(Rgb, false); |
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frameQuantizer = quantizer.CreateFrameQuantizer(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.False(frameQuantizer.Dither); |
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Assert.Null(frameQuantizer.Diffuser); |
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quantizer = new PaletteQuantizer<Rgba32>(Rgb, KnownDiffusers.Atkinson); |
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frameQuantizer = quantizer.CreateFrameQuantizer(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.True(frameQuantizer.Dither); |
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Assert.Equal(KnownDiffusers.Atkinson, frameQuantizer.Diffuser); |
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} |
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[Fact] |
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public void PaletteQuantizerThrowsOnInvalidGenericMethodCall() |
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{ |
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var quantizer = new PaletteQuantizer<Rgba32>(Rgb); |
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Assert.Throws<InvalidOperationException>(() => ((IQuantizer)quantizer).CreateFrameQuantizer<Rgb24>(Configuration.Default)); |
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} |
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[Fact] |
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public void KnownQuantizersWebSafeTests() |
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{ |
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IQuantizer quantizer = KnownQuantizers.WebSafe; |
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Assert.Equal(KnownDiffusers.FloydSteinberg, quantizer.Diffuser); |
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} |
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[Fact] |
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public void KnownQuantizersWernerTests() |
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{ |
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IQuantizer quantizer = KnownQuantizers.Werner; |
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Assert.Equal(KnownDiffusers.FloydSteinberg, quantizer.Diffuser); |
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} |
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} |
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} |
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// Copyright (c) Six Labors and contributors.
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// Licensed under the Apache License, Version 2.0.
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using SixLabors.ImageSharp.PixelFormats; |
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using SixLabors.ImageSharp.Processing; |
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using SixLabors.ImageSharp.Processing.Processors.Quantization; |
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using Xunit; |
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namespace SixLabors.ImageSharp.Tests.Processing.Processors.Quantization |
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{ |
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public class WuQuantizerTests |
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{ |
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[Fact] |
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public void WuQuantizerConstructor() |
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{ |
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var quantizer = new WuQuantizer(128); |
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Assert.Equal(128, quantizer.MaxColors); |
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Assert.Equal(KnownDiffusers.FloydSteinberg, quantizer.Diffuser); |
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quantizer = new WuQuantizer(false); |
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Assert.Equal(QuantizerConstants.MaxColors, quantizer.MaxColors); |
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Assert.Null(quantizer.Diffuser); |
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quantizer = new WuQuantizer(KnownDiffusers.Atkinson); |
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Assert.Equal(QuantizerConstants.MaxColors, quantizer.MaxColors); |
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Assert.Equal(KnownDiffusers.Atkinson, quantizer.Diffuser); |
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quantizer = new WuQuantizer(KnownDiffusers.Atkinson, 128); |
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Assert.Equal(128, quantizer.MaxColors); |
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Assert.Equal(KnownDiffusers.Atkinson, quantizer.Diffuser); |
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} |
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[Fact] |
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public void WuQuantizerCanCreateFrameQuantizer() |
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{ |
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var quantizer = new WuQuantizer(); |
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IFrameQuantizer<Rgba32> frameQuantizer = quantizer.CreateFrameQuantizer<Rgba32>(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.True(frameQuantizer.Dither); |
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Assert.Equal(KnownDiffusers.FloydSteinberg, frameQuantizer.Diffuser); |
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quantizer = new WuQuantizer(false); |
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frameQuantizer = quantizer.CreateFrameQuantizer<Rgba32>(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.False(frameQuantizer.Dither); |
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Assert.Null(frameQuantizer.Diffuser); |
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quantizer = new WuQuantizer(KnownDiffusers.Atkinson); |
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frameQuantizer = quantizer.CreateFrameQuantizer<Rgba32>(Configuration.Default); |
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Assert.NotNull(frameQuantizer); |
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Assert.True(frameQuantizer.Dither); |
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Assert.Equal(KnownDiffusers.Atkinson, frameQuantizer.Diffuser); |
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} |
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} |
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} |
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@ -1 +1 @@ |
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Subproject commit f41ae0327a3ab21ab2388c32160bda67debcc082 |
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Subproject commit ed8a7b0b6fe1b2e2a7c822aa617103ae31192655 |
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