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Faster JpegPixelArea

af/merge-core
James Jackson-South 8 years ago
parent
1821e69e1b
commit
e54c754a9a
2 changed files with 63 additions and 72 deletions
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  1. 81
      src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsJpegPixelArea.cs
  2. 54
      src/ImageSharp/Formats/Jpeg/PdfJsPort/PdfJsJpegDecoderCore.cs

81
src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsJpegPixelArea.cs
View File

@ -5,6 +5,7 @@ using System;
using System.Diagnostics;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using SixLabors.ImageSharp.Memory;
namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
@ -16,14 +17,25 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
{
private readonly MemoryManager memoryManager;
private readonly int imageWidth;
private readonly int imageHeight;
private IBuffer<byte> componentData;
private int rowStride;
/// <summary>
/// Gets the number of components
/// </summary>
public int NumberOfComponents;
/// <summary>
/// Gets the width
/// </summary>
public int Width;
/// <summary>
/// Gets the height
/// </summary>
public int Height;
/// <summary>
/// Initializes a new instance of the <see cref="PdfJsJpegPixelArea"/> struct.
/// </summary>
@ -34,77 +46,52 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
public PdfJsJpegPixelArea(MemoryManager memoryManager, int imageWidth, int imageHeight, int numberOfComponents)
{
this.memoryManager = memoryManager;
this.imageWidth = imageWidth;
this.imageHeight = imageHeight;
this.Width = 0;
this.Height = 0;
this.Width = imageWidth;
this.Height = imageHeight;
this.NumberOfComponents = numberOfComponents;
this.componentData = null;
this.rowStride = 0;
this.rowStride = this.Width * this.NumberOfComponents;
this.componentData = this.memoryManager.Allocate<byte>(this.Width * this.Height * this.NumberOfComponents);
}
/// <summary>
/// Gets the number of components
/// </summary>
public int NumberOfComponents { get; }
/// <summary>
/// Gets the width
/// </summary>
public int Width { get; private set; }
/// <summary>
/// Gets the height
/// </summary>
public int Height { get; private set; }
/// <summary>
/// Organsizes the decoded jpeg components into a linear array ordered by component.
/// This must be called before attempting to retrieve the data.
/// </summary>
/// <param name="components">The jpeg component blocks</param>
/// <param name="width">The pixel area width</param>
/// <param name="height">The pixel area height</param>
public void LinearizeBlockData(PdfJsComponentBlocks components, int width, int height)
public void LinearizeBlockData(PdfJsComponentBlocks components)
{
this.Width = width;
this.Height = height;
int numberOfComponents = this.NumberOfComponents;
this.rowStride = width * numberOfComponents;
var scale = new Vector2(this.imageWidth / (float)width, this.imageHeight / (float)height);
this.componentData = this.memoryManager.Allocate<byte>(width * height * numberOfComponents);
Span<byte> componentDataSpan = this.componentData.Span;
ref byte componentDataRef = ref MemoryMarshal.GetReference(this.componentData.Span);
const uint Mask3Lsb = 0xFFFFFFF8; // Used to clear the 3 LSBs
using (IBuffer<int> xScaleBlockOffset = this.memoryManager.Allocate<int>(width))
using (IBuffer<int> xScaleBlockOffset = this.memoryManager.Allocate<int>(this.Width))
{
Span<int> xScaleBlockOffsetSpan = xScaleBlockOffset.Span;
for (int i = 0; i < numberOfComponents; i++)
ref int xScaleBlockOffsetRef = ref MemoryMarshal.GetReference(xScaleBlockOffset.Span);
for (int i = 0; i < this.NumberOfComponents; i++)
{
ref PdfJsComponent component = ref components.Components[i];
Vector2 componentScale = component.Scale * scale;
int offset = i;
Span<short> output = component.Output.Span;
ref short outputRef = ref MemoryMarshal.GetReference(component.Output.Span);
Vector2 componentScale = component.Scale;
int blocksPerScanline = (component.BlocksPerLine + 1) << 3;
// Precalculate the xScaleBlockOffset
int j;
for (int x = 0; x < width; x++)
for (int x = 0; x < this.Width; x++)
{
j = (int)(x * componentScale.X);
xScaleBlockOffsetSpan[x] = (int)((j & Mask3Lsb) << 3) | (j & 7);
Unsafe.Add(ref xScaleBlockOffsetRef, x) = (int)((j & Mask3Lsb) << 3) | (j & 7);
}
// Linearize the blocks of the component
for (int y = 0; y < height; y++)
int offset = i;
for (int y = 0; y < this.Height; y++)
{
j = (int)(y * componentScale.Y);
int index = blocksPerScanline * (int)(j & Mask3Lsb) | ((j & 7) << 3);
for (int x = 0; x < width; x++)
for (int x = 0; x < this.Width; x++)
{
componentDataSpan[offset] = (byte)output[index + xScaleBlockOffsetSpan[x]];
offset += numberOfComponents;
Unsafe.Add(ref componentDataRef, offset) = (byte)Unsafe.Add(ref outputRef, index + Unsafe.Add(ref xScaleBlockOffsetRef, x));
offset += this.NumberOfComponents;
}
}
}

54
src/ImageSharp/Formats/Jpeg/PdfJsPort/PdfJsJpegDecoderCore.cs
View File

@ -5,6 +5,7 @@ using System;
using System.Buffers.Binary;
using System.IO;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using SixLabors.ImageSharp.Advanced;
using SixLabors.ImageSharp.Formats.Jpeg.Common.Decoder;
using SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components;
@ -336,7 +337,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
}
this.pixelArea = new PdfJsJpegPixelArea(this.configuration.MemoryManager, image.Width, image.Height, this.NumberOfComponents);
this.pixelArea.LinearizeBlockData(this.components, image.Width, image.Height);
this.pixelArea.LinearizeBlockData(this.components);
if (this.NumberOfComponents == 1)
{
@ -838,13 +839,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
{
for (int y = 0; y < image.Height; y++)
{
Span<TPixel> imageRowSpan = image.GetPixelRowSpan(y);
Span<byte> areaRowSpan = this.pixelArea.GetRowSpan(y);
ref TPixel imageRowRef = ref MemoryMarshal.GetReference(image.GetPixelRowSpan(y));
ref byte areaRowRef = ref MemoryMarshal.GetReference(this.pixelArea.GetRowSpan(y));
for (int x = 0; x < image.Width; x++)
{
ref byte luminance = ref areaRowSpan[x];
ref TPixel pixel = ref imageRowSpan[x];
ref byte luminance = ref Unsafe.Add(ref areaRowRef, x);
ref TPixel pixel = ref Unsafe.Add(ref imageRowRef, x);
var rgba = new Rgba32(luminance, luminance, luminance);
pixel.PackFromRgba32(rgba);
}
@ -857,14 +858,15 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
{
for (int y = 0; y < image.Height; y++)
{
Span<TPixel> imageRowSpan = image.GetPixelRowSpan(y);
Span<byte> areaRowSpan = this.pixelArea.GetRowSpan(y);
ref TPixel imageRowRef = ref MemoryMarshal.GetReference(image.GetPixelRowSpan(y));
ref byte areaRowRef = ref MemoryMarshal.GetReference(this.pixelArea.GetRowSpan(y));
for (int x = 0, o = 0; x < image.Width; x++, o += 3)
{
ref byte yy = ref areaRowSpan[o];
ref byte cb = ref areaRowSpan[o + 1];
ref byte cr = ref areaRowSpan[o + 2];
ref TPixel pixel = ref imageRowSpan[x];
ref byte yy = ref Unsafe.Add(ref areaRowRef, o);
ref byte cb = ref Unsafe.Add(ref areaRowRef, o + 1);
ref byte cr = ref Unsafe.Add(ref areaRowRef, o + 2);
ref TPixel pixel = ref Unsafe.Add(ref imageRowRef, x);
PdfJsYCbCrToRgbTables.PackYCbCr(ref pixel, yy, cb, cr);
}
}
@ -876,16 +878,17 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
{
for (int y = 0; y < image.Height; y++)
{
Span<TPixel> imageRowSpan = image.GetPixelRowSpan(y);
Span<byte> areaRowSpan = this.pixelArea.GetRowSpan(y);
ref TPixel imageRowRef = ref MemoryMarshal.GetReference(image.GetPixelRowSpan(y));
ref byte areaRowRef = ref MemoryMarshal.GetReference(this.pixelArea.GetRowSpan(y));
for (int x = 0, o = 0; x < image.Width; x++, o += 4)
{
ref byte yy = ref areaRowSpan[o];
ref byte cb = ref areaRowSpan[o + 1];
ref byte cr = ref areaRowSpan[o + 2];
ref byte k = ref areaRowSpan[o + 3];
ref byte yy = ref Unsafe.Add(ref areaRowRef, o);
ref byte cb = ref Unsafe.Add(ref areaRowRef, o + 1);
ref byte cr = ref Unsafe.Add(ref areaRowRef, o + 2);
ref byte k = ref Unsafe.Add(ref areaRowRef, o + 3);
ref TPixel pixel = ref imageRowSpan[x];
ref TPixel pixel = ref Unsafe.Add(ref imageRowRef, x);
PdfJsYCbCrToRgbTables.PackYccK(ref pixel, yy, cb, cr, k);
}
}
@ -897,20 +900,21 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
{
for (int y = 0; y < image.Height; y++)
{
Span<TPixel> imageRowSpan = image.GetPixelRowSpan(y);
Span<byte> areaRowSpan = this.pixelArea.GetRowSpan(y);
ref TPixel imageRowRef = ref MemoryMarshal.GetReference(image.GetPixelRowSpan(y));
ref byte areaRowRef = ref MemoryMarshal.GetReference(this.pixelArea.GetRowSpan(y));
for (int x = 0, o = 0; x < image.Width; x++, o += 4)
{
ref byte c = ref areaRowSpan[o];
ref byte m = ref areaRowSpan[o + 1];
ref byte cy = ref areaRowSpan[o + 2];
ref byte k = ref areaRowSpan[o + 3];
ref byte c = ref Unsafe.Add(ref areaRowRef, o);
ref byte m = ref Unsafe.Add(ref areaRowRef, o + 1);
ref byte cy = ref Unsafe.Add(ref areaRowRef, o + 2);
ref byte k = ref Unsafe.Add(ref areaRowRef, o + 3);
byte r = (byte)((c * k) / 255);
byte g = (byte)((m * k) / 255);
byte b = (byte)((cy * k) / 255);
ref TPixel pixel = ref imageRowSpan[x];
ref TPixel pixel = ref Unsafe.Add(ref imageRowRef, x);
var rgba = new Rgba32(r, g, b);
pixel.PackFromRgba32(rgba);
}

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