diff --git a/src/ImageSharp/Formats/Bmp/BmpEncoder.cs b/src/ImageSharp/Formats/Bmp/BmpEncoder.cs index f3eb9282c..612675c33 100644 --- a/src/ImageSharp/Formats/Bmp/BmpEncoder.cs +++ b/src/ImageSharp/Formats/Bmp/BmpEncoder.cs @@ -4,6 +4,7 @@ using System.IO; using SixLabors.ImageSharp.Advanced; using SixLabors.ImageSharp.PixelFormats; +using SixLabors.ImageSharp.Processing.Processors.Quantization; namespace SixLabors.ImageSharp.Formats.Bmp { @@ -25,6 +26,12 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// public bool SupportTransparency { get; set; } + /// + /// Gets or sets the quantizer for reducing the color count for 8-Bit images. + /// Defaults to OctreeQuantizer. + /// + public IQuantizer Quantizer { get; set; } + /// public void Encode(Image image, Stream stream) where TPixel : struct, IPixel diff --git a/src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs b/src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs index 8d0e8578d..90ea673d3 100644 --- a/src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs +++ b/src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs @@ -2,6 +2,7 @@ // Licensed under the Apache License, Version 2.0. using System; +using System.Buffers; using System.IO; using SixLabors.ImageSharp.Advanced; @@ -62,6 +63,11 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// private readonly bool writeV4Header; + /// + /// The quantizer for reducing the color count for 8-Bit images. + /// + private readonly IQuantizer quantizer; + /// /// Initializes a new instance of the class. /// @@ -72,6 +78,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp this.memoryAllocator = memoryAllocator; this.bitsPerPixel = options.BitsPerPixel; this.writeV4Header = options.SupportTransparency; + this.quantizer = options.Quantizer ?? new OctreeQuantizer(dither: true, maxColors: 256); } /// @@ -298,39 +305,35 @@ namespace SixLabors.ImageSharp.Formats.Bmp private void Write8Bit(Stream stream, ImageFrame image) where TPixel : struct, IPixel { -#if NETCOREAPP2_1 - Span colorPalette = stackalloc byte[ColorPaletteSize8Bit]; -#else - byte[] colorPalette = new byte[ColorPaletteSize8Bit]; -#endif - - var quantizer = new OctreeQuantizer(dither: true, maxColors: 256); - QuantizedFrame quantized = quantizer.CreateFrameQuantizer(this.configuration).QuantizeFrame(image); - - int idx = 0; - var color = default(Rgba32); - foreach (TPixel quantizedColor in quantized.Palette) + using (IMemoryOwner colorPaletteBuffer = this.memoryAllocator.AllocateManagedByteBuffer(ColorPaletteSize8Bit, AllocationOptions.Clean)) + using (QuantizedFrame quantized = this.quantizer.CreateFrameQuantizer(this.configuration, 256).QuantizeFrame(image)) { - quantizedColor.ToRgba32(ref color); - colorPalette[idx] = color.B; - colorPalette[idx + 1] = color.G; - colorPalette[idx + 2] = color.R; - - // Padding byte, always 0 - colorPalette[idx + 3] = 0; - idx += 4; - } - - stream.Write(colorPalette, 0, ColorPaletteSize8Bit); + Span colorPalette = colorPaletteBuffer.GetSpan(); + int idx = 0; + var color = default(Rgba32); + foreach (TPixel quantizedColor in quantized.Palette) + { + quantizedColor.ToRgba32(ref color); + colorPalette[idx] = color.B; + colorPalette[idx + 1] = color.G; + colorPalette[idx + 2] = color.R; + + // Padding byte, always 0 + colorPalette[idx + 3] = 0; + idx += 4; + } - for (int y = image.Height - 1; y >= 0; y--) - { - Span pixelSpan = quantized.GetRowSpan(y); - stream.Write(pixelSpan); + stream.Write(colorPalette); - for (int i = 0; i < this.padding; i++) + for (int y = image.Height - 1; y >= 0; y--) { - stream.WriteByte(0); + Span pixelSpan = quantized.GetRowSpan(y); + stream.Write(pixelSpan); + + for (int i = 0; i < this.padding; i++) + { + stream.WriteByte(0); + } } } } diff --git a/src/ImageSharp/Formats/Bmp/IBmpEncoderOptions.cs b/src/ImageSharp/Formats/Bmp/IBmpEncoderOptions.cs index 92ff09270..59ad929df 100644 --- a/src/ImageSharp/Formats/Bmp/IBmpEncoderOptions.cs +++ b/src/ImageSharp/Formats/Bmp/IBmpEncoderOptions.cs @@ -1,10 +1,12 @@ // Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. +using SixLabors.ImageSharp.Processing.Processors.Quantization; + namespace SixLabors.ImageSharp.Formats.Bmp { /// - /// Configuration options for use during bmp encoding + /// Configuration options for use during bmp encoding. /// internal interface IBmpEncoderOptions { @@ -20,5 +22,10 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// Instead a bitmap version 4 info header will be written with the BITFIELDS compression. /// bool SupportTransparency { get; } + + /// + /// Gets the quantizer for reducing the color count for 8-Bit images. + /// + IQuantizer Quantizer { get; } } } \ No newline at end of file