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Use encoding method parameter

pull/1552/head
Brian Popow 6 years ago
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733f83a2a0
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9dbd320b62
6 changed files with 71 additions and 25 deletions
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  1. 2
      src/ImageSharp/Formats/WebP/IWebPEncoderOptions.cs
  2. 44
      src/ImageSharp/Formats/WebP/Lossless/Vp8LEncoder.cs
  3. 3
      src/ImageSharp/Formats/WebP/MetadataExtensions.cs
  4. 4
      src/ImageSharp/Formats/WebP/WebPEncoder.cs
  5. 8
      src/ImageSharp/Formats/WebP/WebPEncoderCore.cs
  6. 35
      tests/ImageSharp.Tests/Formats/WebP/WebPEncoderTests.cs

2
src/ImageSharp/Formats/WebP/IWebPEncoderOptions.cs
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@ -19,11 +19,13 @@ namespace SixLabors.ImageSharp.Formats.WebP
/// For lossy, 0 gives the smallest size and 100 the largest. For lossless,
/// this parameter is the amount of effort put into the compression: 0 is the fastest but gives larger
/// files compared to the slowest, but best, 100.
/// Defaults to 75.
/// </summary>
int Quality { get; }
/// <summary>
/// Gets the encoding method to use. Its a quality/speed trade-off (0=fast, 6=slower-better).
/// Defaults to 4.
/// </summary>
int Method { get; }

44
src/ImageSharp/Formats/WebP/Lossless/Vp8LEncoder.cs
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@ -45,6 +45,11 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
/// </summary>
private readonly int quality;
/// <summary>
/// Quality/speed trade-off (0=fast, 6=slower-better).
/// </summary>
private readonly int method;
private const int ApplyPaletteGreedyMax = 4;
private const int PaletteInvSizeBits = 11;
@ -58,12 +63,14 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
/// <param name="width">The width of the input image.</param>
/// <param name="height">The height of the input image.</param>
/// <param name="quality">The encoding quality.</param>
public Vp8LEncoder(MemoryAllocator memoryAllocator, int width, int height, int quality)
/// <param name="method">Quality/speed trade-off (0=fast, 6=slower-better).</param>
public Vp8LEncoder(MemoryAllocator memoryAllocator, int width, int height, int quality, int method)
{
var pixelCount = width * height;
int initialSize = pixelCount * 2;
this.quality = quality.Clamp(1, 100);
this.quality = quality.Clamp(0, 100);
this.method = method.Clamp(0, 6);
this.bitWriter = new Vp8LBitWriter(initialSize);
this.Bgra = memoryAllocator.Allocate<uint>(pixelCount);
this.Palette = memoryAllocator.Allocate<uint>(WebPConstants.MaxPaletteSize);
@ -302,12 +309,12 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
if (this.UsePredictorTransform)
{
this.ApplyPredictFilter(this.CurrentWidth, height, this.quality, this.UseSubtractGreenTransform);
this.ApplyPredictFilter(this.CurrentWidth, height, this.UseSubtractGreenTransform);
}
if (this.UseCrossColorTransform)
{
this.ApplyCrossColorFilter(this.CurrentWidth, height, this.quality);
this.ApplyCrossColorFilter(this.CurrentWidth, height);
}
this.bitWriter.PutBits(0, 1); // No more transforms.
@ -333,7 +340,6 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
private CrunchConfig[] EncoderAnalyze<TPixel>(Image<TPixel> image, out bool redAndBlueAlwaysZero)
where TPixel : unmanaged, IPixel<TPixel>
{
int method = 4; // TODO: method hardcoded to 4 for now.
int width = image.Width;
int height = image.Height;
@ -341,8 +347,8 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
var usePalette = this.AnalyzeAndCreatePalette(image);
// Empirical bit sizes.
this.HistoBits = GetHistoBits(method, usePalette, width, height);
this.TransformBits = GetTransformBits(method, this.HistoBits);
this.HistoBits = GetHistoBits(this.method, usePalette, width, height);
this.TransformBits = GetTransformBits(this.method, this.HistoBits);
// Try out multiple LZ77 on images with few colors.
var nlz77s = (this.PaletteSize > 0 && this.PaletteSize <= 16) ? 2 : 1;
@ -351,7 +357,7 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
bool doNotCache = false;
var crunchConfigs = new List<CrunchConfig>();
if (method == 6 && this.quality == 100)
if (this.method == 6 && this.quality == 100)
{
doNotCache = true;
@ -370,7 +376,7 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
{
// Only choose the guessed best transform.
crunchConfigs.Add(new CrunchConfig { EntropyIdx = entropyIdx });
if (this.quality >= 75 && method == 5)
if (this.quality >= 75 && this.method == 5)
{
// Test with and without color cache.
doNotCache = true;
@ -423,7 +429,7 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
}
// Calculate backward references from BGRA image.
BackwardReferenceEncoder.HashChainFill(hashChain, bgra, quality, width, height);
BackwardReferenceEncoder.HashChainFill(hashChain, bgra, this.quality, width, height);
Vp8LBitWriter bitWriterBest = config.SubConfigs.Count > 1 ? this.bitWriter.Clone() : this.bitWriter;
@ -433,7 +439,7 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
width,
height,
bgra,
quality,
this.quality,
subConfig.Lz77,
ref cacheBits,
hashChain,
@ -455,7 +461,7 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
}
// Build histogram image and symbols from backward references.
HistogramEncoder.GetHistoImageSymbols(width, height, refsBest, quality, histogramBits, cacheBits, histogramImage, tmpHisto, histogramSymbols);
HistogramEncoder.GetHistoImageSymbols(width, height, refsBest, this.quality, histogramBits, cacheBits, histogramImage, tmpHisto, histogramSymbols);
// Create Huffman bit lengths and codes for each histogram image.
var histogramImageSize = histogramImage.Count;
@ -498,7 +504,7 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
}
this.bitWriter.PutBits((uint)(histogramBits - 2), 3);
this.EncodeImageNoHuffman(histogramBgra, hashChain, refsTmp, refsArray[2], LosslessUtils.SubSampleSize(width, histogramBits), LosslessUtils.SubSampleSize(height, histogramBits), quality);
this.EncodeImageNoHuffman(histogramBgra, hashChain, refsTmp, refsArray[2], LosslessUtils.SubSampleSize(width, histogramBits), LosslessUtils.SubSampleSize(height, histogramBits), this.quality);
}
// Store Huffman codes.
@ -572,7 +578,7 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
LosslessUtils.SubtractGreenFromBlueAndRed(this.Bgra.GetSpan(), width * height);
}
private void ApplyPredictFilter(int width, int height, int quality, bool usedSubtractGreen)
private void ApplyPredictFilter(int width, int height, bool usedSubtractGreen)
{
int nearLosslessStrength = 100; // TODO: for now always 100
bool exact = false; // TODO: always false for now.
@ -586,22 +592,22 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
this.bitWriter.PutBits((uint)Vp8LTransformType.PredictorTransform, 2);
this.bitWriter.PutBits((uint)(predBits - 2), 3);
this.EncodeImageNoHuffman(this.TransformData.GetSpan(), this.HashChain, this.Refs[0], this.Refs[1], transformWidth, transformHeight, quality);
this.EncodeImageNoHuffman(this.TransformData.GetSpan(), this.HashChain, this.Refs[0], this.Refs[1], transformWidth, transformHeight, this.quality);
}
private void ApplyCrossColorFilter(int width, int height, int quality)
private void ApplyCrossColorFilter(int width, int height)
{
int colorTransformBits = this.TransformBits;
int transformWidth = LosslessUtils.SubSampleSize(width, colorTransformBits);
int transformHeight = LosslessUtils.SubSampleSize(height, colorTransformBits);
PredictorEncoder.ColorSpaceTransform(width, height, colorTransformBits, quality, this.Bgra.GetSpan(), this.TransformData.GetSpan());
PredictorEncoder.ColorSpaceTransform(width, height, colorTransformBits, this.quality, this.Bgra.GetSpan(), this.TransformData.GetSpan());
this.bitWriter.PutBits(WebPConstants.TransformPresent, 1);
this.bitWriter.PutBits((uint)Vp8LTransformType.CrossColorTransform, 2);
this.bitWriter.PutBits((uint)(colorTransformBits - 2), 3);
this.EncodeImageNoHuffman(this.TransformData.GetSpan(), this.HashChain, this.Refs[0], this.Refs[1], transformWidth, transformHeight, quality);
this.EncodeImageNoHuffman(this.TransformData.GetSpan(), this.HashChain, this.Refs[0], this.Refs[1], transformWidth, transformHeight, this.quality);
}
private void EncodeImageNoHuffman(Span<uint> bgra, Vp8LHashChain hashChain, Vp8LBackwardRefs refsTmp1, Vp8LBackwardRefs refsTmp2, int width, int height, int quality)
@ -1488,7 +1494,7 @@ namespace SixLabors.ImageSharp.Formats.WebP.Lossless
var huffTree = new HuffmanTree[3 * maxNumSymbols];
for (int i = 0; i < huffTree.Length; i++)
{
huffTree[i] = new HuffmanTree();
huffTree[i] = default;
}
for (int i = 0; i < histogramImage.Count; i++)

3
src/ImageSharp/Formats/WebP/MetadataExtensions.cs
View File

@ -1,3 +1,6 @@
// Copyright (c) Six Labors.
// Licensed under the Apache License, Version 2.0.
using SixLabors.ImageSharp.Formats.WebP;
using SixLabors.ImageSharp.Metadata;

4
src/ImageSharp/Formats/WebP/WebPEncoder.cs
View File

@ -18,10 +18,10 @@ namespace SixLabors.ImageSharp.Formats.WebP
public bool Lossy { get; set; }
/// <inheritdoc/>
public int Quality { get; set; }
public int Quality { get; set; } = 75;
/// <inheritdoc/>
public int Method { get; set; }
public int Method { get; set; } = 4;
/// <inheritdoc/>
public bool AlphaCompression { get; set; }

8
src/ImageSharp/Formats/WebP/WebPEncoderCore.cs
View File

@ -43,6 +43,11 @@ namespace SixLabors.ImageSharp.Formats.WebP
/// </summary>
private readonly int quality;
/// <summary>
/// Quality/speed trade-off (0=fast, 6=slower-better).
/// </summary>
private readonly int method;
/// <summary>
/// Initializes a new instance of the <see cref="WebPEncoderCore"/> class.
/// </summary>
@ -54,6 +59,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
this.alphaCompression = options.AlphaCompression;
this.lossy = options.Lossy;
this.quality = options.Quality;
this.method = options.Method;
}
/// <summary>
@ -78,7 +84,7 @@ namespace SixLabors.ImageSharp.Formats.WebP
}
else
{
var enc = new Vp8LEncoder(this.memoryAllocator, image.Width, image.Height, this.quality);
var enc = new Vp8LEncoder(this.memoryAllocator, image.Width, image.Height, this.quality, this.method);
enc.Encode(image, stream);
}
}

35
tests/ImageSharp.Tests/Formats/WebP/WebPEncoderTests.cs
View File

@ -1,3 +1,6 @@
// Copyright (c) Six Labors.
// Licensed under the Apache License, Version 2.0.
using SixLabors.ImageSharp.Formats.WebP;
using SixLabors.ImageSharp.PixelFormats;
using Xunit;
@ -12,17 +15,43 @@ namespace SixLabors.ImageSharp.Tests.Formats.WebP
[WithFile(TestImages.Bmp.Car, PixelTypes.Rgba32, 100)]
[WithFile(TestImages.Bmp.Car, PixelTypes.Rgba32, 80)]
[WithFile(TestImages.Bmp.Car, PixelTypes.Rgba32, 20)]
public void Encode_Lossless_Works<TPixel>(TestImageProvider<TPixel> provider, int quality)
public void Encode_Lossless_WithDifferentQuality_Works<TPixel>(TestImageProvider<TPixel> provider, int quality)
where TPixel : unmanaged, IPixel<TPixel>
{
var encoder = new WebPEncoder()
{
Lossy = false,
Quality = quality
};
using (Image<TPixel> image = provider.GetImage())
{
var testOutputDetails = string.Concat("lossless", "_q", quality);
image.VerifyEncoder(provider, "webp", testOutputDetails, encoder);
}
}
[Theory]
[WithFile(Lossy.NoFilter06, PixelTypes.Rgba32, 0)]
[WithFile(Lossy.NoFilter06, PixelTypes.Rgba32, 1)]
[WithFile(Lossy.NoFilter06, PixelTypes.Rgba32, 2)]
[WithFile(Lossy.NoFilter06, PixelTypes.Rgba32, 3)]
[WithFile(Lossy.NoFilter06, PixelTypes.Rgba32, 4)]
[WithFile(Lossy.NoFilter06, PixelTypes.Rgba32, 5)]
[WithFile(Lossy.NoFilter06, PixelTypes.Rgba32, 6)]
public void Encode_Lossless_WithDifferentMethods_Works<TPixel>(TestImageProvider<TPixel> provider, int method)
where TPixel : unmanaged, IPixel<TPixel>
{
var encoder = new WebPEncoder()
{
Lossy = false
Lossy = false,
Method = method,
Quality = 100
};
using (Image<TPixel> image = provider.GetImage())
{
var testOutputDetails = string.Concat("lossless", "_", quality);
var testOutputDetails = string.Concat("lossless", "_m", method);
image.VerifyEncoder(provider, "webp", testOutputDetails, encoder);
}
}

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