tsai
/
ImageSharp
mirror of https://github.com/SixLabors/ImageSharp
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

refactor subsampling + better IDCT constants in actual implementation

pull/322/head
Anton Firszov 9 years ago
parent
279bb7b946
commit
0614e3fe3a
6 changed files with 123 additions and 109 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 24
      src/ImageSharp/Formats/Jpeg/Common/FastFloatingPointDCT.cs
  2. 68
      src/ImageSharp/Formats/Jpeg/GolangPort/Components/Decoder/SubsampleRatio.cs
  3. 62
      src/ImageSharp/Formats/Jpeg/GolangPort/Components/Decoder/YCbCrImage.cs
  4. 30
      src/ImageSharp/Formats/Jpeg/GolangPort/OrigJpegDecoderCore.cs
  5. 16
      tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.cs
  6. 32
      tests/ImageSharp.Tests/Formats/Jpg/YCbCrImageTests.cs

24
src/ImageSharp/Formats/Jpeg/Common/FastFloatingPointDCT.cs
View File

@ -13,29 +13,29 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Common
internal static class FastFloatingPointDCT internal static class FastFloatingPointDCT
{ {
#pragma warning disable SA1310 // FieldNamesMustNotContainUnderscore #pragma warning disable SA1310 // FieldNamesMustNotContainUnderscore
private static readonly float C_1_175876 = 1.175876f; private static readonly float C_1_175876 = 1.175875602f;
private static readonly float C_1_961571 = -1.961571f; private static readonly float C_1_961571 = -1.961570560f;
private static readonly float C_0_390181 = -0.390181f; private static readonly float C_0_390181 = -0.390180644f;
private static readonly float C_0_899976 = -0.899976f; private static readonly float C_0_899976 = -0.899976223f;
private static readonly float C_2_562915 = -2.562915f; private static readonly float C_2_562915 = -2.562915447f;
private static readonly float C_0_298631 = 0.298631f; private static readonly float C_0_298631 = 0.298631336f;
private static readonly float C_2_053120 = 2.053120f; private static readonly float C_2_053120 = 2.053119869f;
private static readonly float C_3_072711 = 3.072711f; private static readonly float C_3_072711 = 3.072711026f;
private static readonly float C_1_501321 = 1.501321f; private static readonly float C_1_501321 = 1.501321110f;
private static readonly float C_0_541196 = 0.541196f; private static readonly float C_0_541196 = 0.541196100f;
private static readonly float C_1_847759 = -1.847759f; private static readonly float C_1_847759 = -1.847759065f;
private static readonly float C_0_765367 = 0.765367f; private static readonly float C_0_765367 = 0.765366865f;
private static readonly float C_0_125 = 0.1250f; private static readonly float C_0_125 = 0.1250f;
#pragma warning restore SA1310 // FieldNamesMustNotContainUnderscore #pragma warning restore SA1310 // FieldNamesMustNotContainUnderscore

68
src/ImageSharp/Formats/Jpeg/GolangPort/Components/Decoder/SubsampleRatio.cs
View File

@ -0,0 +1,68 @@
namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
{
/// <summary>
/// Provides enumeration of the various available subsample ratios.
/// https://en.wikipedia.org/wiki/Chroma_subsampling
/// </summary>
internal enum SubsampleRatio
{
Undefined,
/// <summary>
/// 4:4:4
/// </summary>
Ratio444,
/// <summary>
/// 4:2:2
/// </summary>
Ratio422,
/// <summary>
/// 4:2:0
/// </summary>
Ratio420,
/// <summary>
/// 4:4:0
/// </summary>
Ratio440,
/// <summary>
/// 4:1:1
/// </summary>
Ratio411,
/// <summary>
/// 4:1:0
/// </summary>
Ratio410,
}
/// <summary>
/// Various utilities for <see cref="SubsampleRatio"/>
/// </summary>
internal static class Subsampling
{
public static SubsampleRatio GetSubsampleRatio(int horizontalRatio, int verticalRatio)
{
switch ((horizontalRatio << 4) | verticalRatio)
{
case 0x11:
return SubsampleRatio.Ratio444;
case 0x12:
return SubsampleRatio.Ratio440;
case 0x21:
return SubsampleRatio.Ratio422;
case 0x22:
return SubsampleRatio.Ratio420;
case 0x41:
return SubsampleRatio.Ratio411;
case 0x42:
return SubsampleRatio.Ratio410;
}
return SubsampleRatio.Ratio444;
}
}
}

62
src/ImageSharp/Formats/Jpeg/GolangPort/Components/Decoder/YCbCrImage.cs
View File

@ -36,7 +36,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
/// <param name="width">The width.</param> /// <param name="width">The width.</param>
/// <param name="height">The height.</param> /// <param name="height">The height.</param>
/// <param name="ratio">The ratio.</param> /// <param name="ratio">The ratio.</param>
public YCbCrImage(int width, int height, YCbCrSubsampleRatio ratio) public YCbCrImage(int width, int height, SubsampleRatio ratio)
{ {
Size cSize = CalculateChrominanceSize(width, height, ratio); Size cSize = CalculateChrominanceSize(width, height, ratio);
@ -49,42 +49,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
this.CrChannel = Buffer2D<byte>.CreateClean(cSize.Width, cSize.Height); this.CrChannel = Buffer2D<byte>.CreateClean(cSize.Width, cSize.Height);
} }
/// <summary>
/// Provides enumeration of the various available subsample ratios.
/// </summary>
public enum YCbCrSubsampleRatio
{
/// <summary>
/// YCbCrSubsampleRatio444
/// </summary>
YCbCrSubsampleRatio444,
/// <summary>
/// YCbCrSubsampleRatio422
/// </summary>
YCbCrSubsampleRatio422,
/// <summary>
/// YCbCrSubsampleRatio420
/// </summary>
YCbCrSubsampleRatio420,
/// <summary>
/// YCbCrSubsampleRatio440
/// </summary>
YCbCrSubsampleRatio440,
/// <summary>
/// YCbCrSubsampleRatio411
/// </summary>
YCbCrSubsampleRatio411,
/// <summary>
/// YCbCrSubsampleRatio410
/// </summary>
YCbCrSubsampleRatio410,
}
/// <summary> /// <summary>
/// Gets the Y slice index delta between vertically adjacent pixels. /// Gets the Y slice index delta between vertically adjacent pixels.
/// </summary> /// </summary>
@ -99,7 +63,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
/// <summary> /// <summary>
/// Gets or sets the subsampling ratio. /// Gets or sets the subsampling ratio.
/// </summary> /// </summary>
public YCbCrSubsampleRatio Ratio { get; set; } public SubsampleRatio Ratio { get; set; }
/// <summary> /// <summary>
/// Disposes the <see cref="YCbCrImage" /> returning rented arrays to the pools. /// Disposes the <see cref="YCbCrImage" /> returning rented arrays to the pools.
@ -122,15 +86,15 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
{ {
switch (this.Ratio) switch (this.Ratio)
{ {
case YCbCrSubsampleRatio.YCbCrSubsampleRatio422: case SubsampleRatio.Ratio422:
return y * this.CStride; return y * this.CStride;
case YCbCrSubsampleRatio.YCbCrSubsampleRatio420: case SubsampleRatio.Ratio420:
return (y / 2) * this.CStride; return (y / 2) * this.CStride;
case YCbCrSubsampleRatio.YCbCrSubsampleRatio440: case SubsampleRatio.Ratio440:
return (y / 2) * this.CStride; return (y / 2) * this.CStride;
case YCbCrSubsampleRatio.YCbCrSubsampleRatio411: case SubsampleRatio.Ratio411:
return y * this.CStride; return y * this.CStride;
case YCbCrSubsampleRatio.YCbCrSubsampleRatio410: case SubsampleRatio.Ratio410:
return (y / 2) * this.CStride; return (y / 2) * this.CStride;
default: default:
return y * this.CStride; return y * this.CStride;
@ -159,19 +123,19 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
internal static Size CalculateChrominanceSize( internal static Size CalculateChrominanceSize(
int width, int width,
int height, int height,
YCbCrSubsampleRatio ratio) SubsampleRatio ratio)
{ {
switch (ratio) switch (ratio)
{ {
case YCbCrSubsampleRatio.YCbCrSubsampleRatio422: case SubsampleRatio.Ratio422:
return new Size((width + 1) / 2, height); return new Size((width + 1) / 2, height);
case YCbCrSubsampleRatio.YCbCrSubsampleRatio420: case SubsampleRatio.Ratio420:
return new Size((width + 1) / 2, (height + 1) / 2); return new Size((width + 1) / 2, (height + 1) / 2);
case YCbCrSubsampleRatio.YCbCrSubsampleRatio440: case SubsampleRatio.Ratio440:
return new Size(width, (height + 1) / 2); return new Size(width, (height + 1) / 2);
case YCbCrSubsampleRatio.YCbCrSubsampleRatio411: case SubsampleRatio.Ratio411:
return new Size((width + 3) / 4, height); return new Size((width + 3) / 4, height);
case YCbCrSubsampleRatio.YCbCrSubsampleRatio410: case SubsampleRatio.Ratio410:
return new Size((width + 3) / 4, (height + 1) / 2); return new Size((width + 3) / 4, (height + 1) / 2);
default: default:
// Default to 4:4:4 subsampling. // Default to 4:4:4 subsampling.

30
src/ImageSharp/Formats/Jpeg/GolangPort/OrigJpegDecoderCore.cs
View File

@ -111,6 +111,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
this.Temp = new byte[2 * Block8x8F.Size]; this.Temp = new byte[2 * Block8x8F.Size];
} }
/// <summary>
/// Gets the <see cref="GolangPort.Components.Decoder.SubsampleRatio"/> ratio.
/// </summary>
public SubsampleRatio SubsampleRatio { get; private set; }
/// <summary> /// <summary>
/// Gets the component array /// Gets the component array
/// </summary> /// </summary>
@ -780,6 +785,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
return; return;
} }
this.SubsampleRatio = GolangPort.Components.Decoder.SubsampleRatio.Undefined;
if (this.ComponentCount == 1) if (this.ComponentCount == 1)
{ {
Buffer2D<byte> buffer = Buffer2D<byte>.CreateClean(8 * this.MCUCountX, 8 * this.MCUCountY); Buffer2D<byte> buffer = Buffer2D<byte>.CreateClean(8 * this.MCUCountX, 8 * this.MCUCountY);
@ -792,28 +799,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
int horizontalRatio = h0 / this.Components[1].HorizontalFactor; int horizontalRatio = h0 / this.Components[1].HorizontalFactor;
int verticalRatio = v0 / this.Components[1].VerticalFactor; int verticalRatio = v0 / this.Components[1].VerticalFactor;
YCbCrImage.YCbCrSubsampleRatio ratio = YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio444; SubsampleRatio ratio = Subsampling.GetSubsampleRatio(horizontalRatio, verticalRatio);
switch ((horizontalRatio << 4) | verticalRatio)
{
case 0x11:
ratio = YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio444;
break;
case 0x12:
ratio = YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio440;
break;
case 0x21:
ratio = YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio422;
break;
case 0x22:
ratio = YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio420;
break;
case 0x41:
ratio = YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio411;
break;
case 0x42:
ratio = YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio410;
break;
}
this.ycbcrImage = new YCbCrImage(8 * h0 * this.MCUCountX, 8 * v0 * this.MCUCountY, ratio); this.ycbcrImage = new YCbCrImage(8 * h0 * this.MCUCountX, 8 * v0 * this.MCUCountY, ratio);

16
tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.cs
View File

@ -55,11 +55,11 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
private ITestOutputHelper Output { get; } private ITestOutputHelper Output { get; }
private static IImageDecoder OldJpegDecoder => new OrigJpegDecoder(); private static IImageDecoder OrigJpegDecoder => new OrigJpegDecoder();
private static IImageDecoder PdfJsJpegDecoder => new JpegDecoder(); private static IImageDecoder PdfJsJpegDecoder => new JpegDecoder();
[Fact] [Fact(Skip = "Doesn't really matter")]
public void ParseStream_BasicPropertiesAreCorrect1_Orig() public void ParseStream_BasicPropertiesAreCorrect1_Orig()
{ {
byte[] bytes = TestFile.Create(TestImages.Jpeg.Progressive.Progress).Bytes; byte[] bytes = TestFile.Create(TestImages.Jpeg.Progressive.Progress).Bytes;
@ -108,7 +108,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
public void JpegDecoder_IsNotBoundToSinglePixelType<TPixel>(TestImageProvider<TPixel> provider, bool useOldDecoder) public void JpegDecoder_IsNotBoundToSinglePixelType<TPixel>(TestImageProvider<TPixel> provider, bool useOldDecoder)
where TPixel : struct, IPixel<TPixel> where TPixel : struct, IPixel<TPixel>
{ {
IImageDecoder decoder = useOldDecoder ? OldJpegDecoder : PdfJsJpegDecoder; IImageDecoder decoder = useOldDecoder ? OrigJpegDecoder : PdfJsJpegDecoder;
using (Image<TPixel> image = provider.GetImage(decoder)) using (Image<TPixel> image = provider.GetImage(decoder))
{ {
image.DebugSave(provider); image.DebugSave(provider);
@ -123,7 +123,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
public void DecodeBaselineJpeg_Orig<TPixel>(TestImageProvider<TPixel> provider) public void DecodeBaselineJpeg_Orig<TPixel>(TestImageProvider<TPixel> provider)
where TPixel : struct, IPixel<TPixel> where TPixel : struct, IPixel<TPixel>
{ {
using (Image<TPixel> image = provider.GetImage(OldJpegDecoder)) using (Image<TPixel> image = provider.GetImage(OrigJpegDecoder))
{ {
image.DebugSave(provider); image.DebugSave(provider);
@ -153,7 +153,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
public void DecodeProgressiveJpeg_Orig<TPixel>(TestImageProvider<TPixel> provider) public void DecodeProgressiveJpeg_Orig<TPixel>(TestImageProvider<TPixel> provider)
where TPixel : struct, IPixel<TPixel> where TPixel : struct, IPixel<TPixel>
{ {
using (Image<TPixel> image = provider.GetImage(OldJpegDecoder)) using (Image<TPixel> image = provider.GetImage(OrigJpegDecoder))
{ {
image.DebugSave(provider); image.DebugSave(provider);
@ -187,7 +187,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
this.Output.WriteLine(provider.SourceFileOrDescription); this.Output.WriteLine(provider.SourceFileOrDescription);
provider.Utility.TestName = testName; provider.Utility.TestName = testName;
using (Image<TPixel> image = provider.GetImage(OldJpegDecoder)) using (Image<TPixel> image = provider.GetImage(OrigJpegDecoder))
{ {
double d = this.GetDifferenceInPercents(image, provider); double d = this.GetDifferenceInPercents(image, provider);
this.Output.WriteLine($"Difference using ORIGINAL decoder: {d:0.0000}%"); this.Output.WriteLine($"Difference using ORIGINAL decoder: {d:0.0000}%");
@ -222,7 +222,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
[WithSolidFilledImages(16, 16, 255, 0, 0, PixelTypes.Rgba32, JpegSubsample.Ratio444, 75)] [WithSolidFilledImages(16, 16, 255, 0, 0, PixelTypes.Rgba32, JpegSubsample.Ratio444, 75)]
[WithSolidFilledImages(16, 16, 255, 0, 0, PixelTypes.Rgba32, JpegSubsample.Ratio444, 100)] [WithSolidFilledImages(16, 16, 255, 0, 0, PixelTypes.Rgba32, JpegSubsample.Ratio444, 100)]
[WithSolidFilledImages(8, 8, 255, 0, 0, PixelTypes.Rgba32, JpegSubsample.Ratio444, 100)] [WithSolidFilledImages(8, 8, 255, 0, 0, PixelTypes.Rgba32, JpegSubsample.Ratio444, 100)]
public void DecodeGenerated<TPixel>( public void DecodeGenerated_Orig<TPixel>(
TestImageProvider<TPixel> provider, TestImageProvider<TPixel> provider,
JpegSubsample subsample, JpegSubsample subsample,
int quality) int quality)
@ -240,7 +240,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
} }
} }
var mirror = Image.Load<TPixel>(data); var mirror = Image.Load<TPixel>(data, OrigJpegDecoder);
mirror.DebugSave(provider, $"_{subsample}_Q{quality}"); mirror.DebugSave(provider, $"_{subsample}_Q{quality}");
} }

32
tests/ImageSharp.Tests/Formats/Jpg/YCbCrImageTests.cs
View File

@ -19,19 +19,17 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
private ITestOutputHelper Output { get; } private ITestOutputHelper Output { get; }
[Theory] [Theory]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio410, 4, 2)] [InlineData(SubsampleRatio.Ratio410, 4, 2)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio411, 4, 1)] [InlineData(SubsampleRatio.Ratio411, 4, 1)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio420, 2, 2)] [InlineData(SubsampleRatio.Ratio420, 2, 2)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio422, 2, 1)] [InlineData(SubsampleRatio.Ratio422, 2, 1)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio440, 1, 2)] [InlineData(SubsampleRatio.Ratio440, 1, 2)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio444, 1, 1)] [InlineData(SubsampleRatio.Ratio444, 1, 1)]
internal void CalculateChrominanceSize( internal void CalculateChrominanceSize(
YCbCrImage.YCbCrSubsampleRatio ratioValue, SubsampleRatio ratio,
int expectedDivX, int expectedDivX,
int expectedDivY) int expectedDivY)
{ {
YCbCrImage.YCbCrSubsampleRatio ratio = (YCbCrImage.YCbCrSubsampleRatio)ratioValue;
//this.Output.WriteLine($"RATIO: {ratio}"); //this.Output.WriteLine($"RATIO: {ratio}");
Size size = YCbCrImage.CalculateChrominanceSize(400, 400, ratio); Size size = YCbCrImage.CalculateChrominanceSize(400, 400, ratio);
//this.Output.WriteLine($"Ch Size: {size}"); //this.Output.WriteLine($"Ch Size: {size}");
@ -40,16 +38,14 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
} }
[Theory] [Theory]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio410, 4)] [InlineData(SubsampleRatio.Ratio410, 4)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio411, 4)] [InlineData(SubsampleRatio.Ratio411, 4)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio420, 2)] [InlineData(SubsampleRatio.Ratio420, 2)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio422, 2)] [InlineData(SubsampleRatio.Ratio422, 2)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio440, 1)] [InlineData(SubsampleRatio.Ratio440, 1)]
[InlineData(YCbCrImage.YCbCrSubsampleRatio.YCbCrSubsampleRatio444, 1)] [InlineData(SubsampleRatio.Ratio444, 1)]
internal void Create(YCbCrImage.YCbCrSubsampleRatio ratioValue, int expectedCStrideDiv) internal void Create(SubsampleRatio ratio, int expectedCStrideDiv)
{ {
YCbCrImage.YCbCrSubsampleRatio ratio = (YCbCrImage.YCbCrSubsampleRatio)ratioValue;
this.Output.WriteLine($"RATIO: {ratio}"); this.Output.WriteLine($"RATIO: {ratio}");
YCbCrImage img = new YCbCrImage(400, 400, ratio); YCbCrImage img = new YCbCrImage(400, 400, ratio);

Write Preview
Loading…
Cancel
Save