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

Merge branch 'main' into js/colorspace-converter

pull/2739/head
James Jackson-South 2 years ago
committed by GitHub
parent
783884853c 59de13c8cc
commit
71d49ae8f9
No known key found for this signature in database GPG Key ID: B5690EEEBB952194
12 changed files with 295 additions and 286 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. 188
      src/ImageSharp/Formats/Gif/GifDecoderCore.cs
  2. 330
      src/ImageSharp/Formats/Gif/LzwDecoder.cs
  3. 2
      src/ImageSharp/Formats/Jpeg/Components/Quantization.cs
  4. 11
      tests/ImageSharp.Tests/Formats/Gif/GifDecoderTests.cs
  5. 28
      tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.Metadata.cs
  6. 2
      tests/ImageSharp.Tests/TestImages.cs
  7. 4
      tests/Images/External/ReferenceOutput/GifDecoderTests/Issue2012BadMinCode_Rgba32_issue2012_drona1.png
  8. 3
      tests/Images/External/ReferenceOutput/GifDecoderTests/Issue2758_BadDescriptorDimensions_Rgba32_issue_2758.gif/00.png
  9. 3
      tests/Images/External/ReferenceOutput/GifDecoderTests/Issue2758_BadDescriptorDimensions_Rgba32_issue_2758.gif/01.png
  10. 4
      tests/Images/External/ReferenceOutput/GifDecoderTests/IssueTooLargeLzwBits_Rgba32_issue_2743.gif/07.png
  11. 3
      tests/Images/Input/Gif/issues/issue_2758.gif
  12. 3
      tests/Images/Input/Jpg/issues/issue-2758.jpg

188
src/ImageSharp/Formats/Gif/GifDecoderCore.cs
View File

@ -427,68 +427,49 @@ internal sealed class GifDecoderCore : IImageDecoderInternals
{ {
this.ReadImageDescriptor(stream); this.ReadImageDescriptor(stream);
Buffer2D<byte>? indices = null; // Determine the color table for this frame. If there is a local one, use it otherwise use the global color table.
try bool hasLocalColorTable = this.imageDescriptor.LocalColorTableFlag;
{
// Determine the color table for this frame. If there is a local one, use it otherwise use the global color table.
bool hasLocalColorTable = this.imageDescriptor.LocalColorTableFlag;
if (hasLocalColorTable)
{
// Read and store the local color table. We allocate the maximum possible size and slice to match.
int length = this.currentLocalColorTableSize = this.imageDescriptor.LocalColorTableSize * 3;
this.currentLocalColorTable ??= this.configuration.MemoryAllocator.Allocate<byte>(768, AllocationOptions.Clean);
stream.Read(this.currentLocalColorTable.GetSpan()[..length]);
}
indices = this.configuration.MemoryAllocator.Allocate2D<byte>(this.imageDescriptor.Width, this.imageDescriptor.Height, AllocationOptions.Clean);
this.ReadFrameIndices(stream, indices);
Span<byte> rawColorTable = default; if (hasLocalColorTable)
if (hasLocalColorTable) {
{ // Read and store the local color table. We allocate the maximum possible size and slice to match.
rawColorTable = this.currentLocalColorTable!.GetSpan()[..this.currentLocalColorTableSize]; int length = this.currentLocalColorTableSize = this.imageDescriptor.LocalColorTableSize * 3;
} this.currentLocalColorTable ??= this.configuration.MemoryAllocator.Allocate<byte>(768, AllocationOptions.Clean);
else if (this.globalColorTable != null) stream.Read(this.currentLocalColorTable.GetSpan()[..length]);
{ }
rawColorTable = this.globalColorTable.GetSpan();
}
ReadOnlySpan<Rgb24> colorTable = MemoryMarshal.Cast<byte, Rgb24>(rawColorTable);
this.ReadFrameColors(ref image, ref previousFrame, indices, colorTable, this.imageDescriptor);
// Skip any remaining blocks Span<byte> rawColorTable = default;
SkipBlock(stream); if (hasLocalColorTable)
{
rawColorTable = this.currentLocalColorTable!.GetSpan()[..this.currentLocalColorTableSize];
} }
finally else if (this.globalColorTable != null)
{ {
indices?.Dispose(); rawColorTable = this.globalColorTable.GetSpan();
} }
}
/// <summary> ReadOnlySpan<Rgb24> colorTable = MemoryMarshal.Cast<byte, Rgb24>(rawColorTable);
/// Reads the frame indices marking the color to use for each pixel. this.ReadFrameColors(stream, ref image, ref previousFrame, colorTable, this.imageDescriptor);
/// </summary>
/// <param name="stream">The <see cref="BufferedReadStream"/> containing image data.</param> // Skip any remaining blocks
/// <param name="indices">The 2D pixel buffer to write to.</param> SkipBlock(stream);
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void ReadFrameIndices(BufferedReadStream stream, Buffer2D<byte> indices)
{
int minCodeSize = stream.ReadByte();
using LzwDecoder lzwDecoder = new(this.configuration.MemoryAllocator, stream);
lzwDecoder.DecodePixels(minCodeSize, indices);
} }
/// <summary> /// <summary>
/// Reads the frames colors, mapping indices to colors. /// Reads the frames colors, mapping indices to colors.
/// </summary> /// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam> /// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="stream">The <see cref="BufferedReadStream"/> containing image data.</param>
/// <param name="image">The image to decode the information to.</param> /// <param name="image">The image to decode the information to.</param>
/// <param name="previousFrame">The previous frame.</param> /// <param name="previousFrame">The previous frame.</param>
/// <param name="indices">The indexed pixels.</param>
/// <param name="colorTable">The color table containing the available colors.</param> /// <param name="colorTable">The color table containing the available colors.</param>
/// <param name="descriptor">The <see cref="GifImageDescriptor"/></param> /// <param name="descriptor">The <see cref="GifImageDescriptor"/></param>
private void ReadFrameColors<TPixel>(ref Image<TPixel>? image, ref ImageFrame<TPixel>? previousFrame, Buffer2D<byte> indices, ReadOnlySpan<Rgb24> colorTable, in GifImageDescriptor descriptor) private void ReadFrameColors<TPixel>(
BufferedReadStream stream,
ref Image<TPixel>? image,
ref ImageFrame<TPixel>? previousFrame,
ReadOnlySpan<Rgb24> colorTable,
in GifImageDescriptor descriptor)
where TPixel : unmanaged, IPixel<TPixel> where TPixel : unmanaged, IPixel<TPixel>
{ {
int imageWidth = this.logicalScreenDescriptor.Width; int imageWidth = this.logicalScreenDescriptor.Width;
@ -549,69 +530,79 @@ internal sealed class GifDecoderCore : IImageDecoderInternals
byte transIndex = this.graphicsControlExtension.TransparencyIndex; byte transIndex = this.graphicsControlExtension.TransparencyIndex;
int colorTableMaxIdx = colorTable.Length - 1; int colorTableMaxIdx = colorTable.Length - 1;
for (int y = descriptorTop; y < descriptorBottom && y < imageHeight; y++) // For a properly encoded gif the descriptor dimensions will never exceed the logical screen dimensions.
// However we have images that exceed this that can be decoded by other libraries. #1530
using IMemoryOwner<byte> indicesRowOwner = this.memoryAllocator.Allocate<byte>(descriptor.Width);
Span<byte> indicesRow = indicesRowOwner.Memory.Span;
ref byte indicesRowRef = ref MemoryMarshal.GetReference(indicesRow);
int minCodeSize = stream.ReadByte();
if (LzwDecoder.IsValidMinCodeSize(minCodeSize))
{ {
ref byte indicesRowRef = ref MemoryMarshal.GetReference(indices.DangerousGetRowSpan(y - descriptorTop)); using LzwDecoder lzwDecoder = new(this.configuration.MemoryAllocator, stream, minCodeSize);
// Check if this image is interlaced. for (int y = descriptorTop; y < descriptorBottom && y < imageHeight; y++)
int writeY; // the target y offset to write to
if (descriptor.InterlaceFlag)
{ {
// If so then we read lines at predetermined offsets. // Check if this image is interlaced.
// When an entire image height worth of offset lines has been read we consider this a pass. int writeY; // the target y offset to write to
// With each pass the number of offset lines changes and the starting line changes. if (descriptor.InterlaceFlag)
if (interlaceY >= descriptor.Height)
{ {
interlacePass++; // If so then we read lines at predetermined offsets.
switch (interlacePass) // When an entire image height worth of offset lines has been read we consider this a pass.
// With each pass the number of offset lines changes and the starting line changes.
if (interlaceY >= descriptor.Height)
{ {
case 1: interlacePass++;
interlaceY = 4; switch (interlacePass)
break; {
case 2: case 1:
interlaceY = 2; interlaceY = 4;
interlaceIncrement = 4; break;
break; case 2:
case 3: interlaceY = 2;
interlaceY = 1; interlaceIncrement = 4;
interlaceIncrement = 2; break;
break; case 3:
interlaceY = 1;
interlaceIncrement = 2;
break;
}
} }
}
writeY = interlaceY + descriptor.Top; writeY = Math.Min(interlaceY + descriptor.Top, image.Height);
interlaceY += interlaceIncrement; interlaceY += interlaceIncrement;
} }
else else
{ {
writeY = y; writeY = y;
} }
ref TPixel rowRef = ref MemoryMarshal.GetReference(imageFrame.PixelBuffer.DangerousGetRowSpan(writeY)); lzwDecoder.DecodePixelRow(indicesRow);
ref TPixel rowRef = ref MemoryMarshal.GetReference(imageFrame.PixelBuffer.DangerousGetRowSpan(writeY));
if (!transFlag) if (!transFlag)
{
// #403 The left + width value can be larger than the image width
for (int x = descriptorLeft; x < descriptorRight && x < imageWidth; x++)
{ {
int index = Numerics.Clamp(Unsafe.Add(ref indicesRowRef, (uint)(x - descriptorLeft)), 0, colorTableMaxIdx); // #403 The left + width value can be larger than the image width
Unsafe.Add(ref rowRef, (uint)x) = TPixel.FromRgb24(colorTable[index]); for (int x = descriptorLeft; x < descriptorRight && x < imageWidth; x++)
{
int index = Numerics.Clamp(Unsafe.Add(ref indicesRowRef, (uint)(x - descriptorLeft)), 0, colorTableMaxIdx);
Unsafe.Add(ref rowRef, (uint)x) = TPixel.FromRgb24(colorTable[index]);
}
} }
} else
else
{
for (int x = descriptorLeft; x < descriptorRight && x < imageWidth; x++)
{ {
int rawIndex = Unsafe.Add(ref indicesRowRef, (uint)(x - descriptorLeft)); for (int x = descriptorLeft; x < descriptorRight && x < imageWidth; x++)
// Treat any out of bounds values as transparent.
if (rawIndex > colorTableMaxIdx || rawIndex == transIndex)
{ {
continue; int index = Unsafe.Add(ref indicesRowRef, (uint)(x - descriptorLeft));
}
// Treat any out of bounds values as transparent.
if (index > colorTableMaxIdx || index == transIndex)
{
continue;
}
int index = Numerics.Clamp(rawIndex, 0, colorTableMaxIdx); Unsafe.Add(ref rowRef, (uint)x) = TPixel.FromRgb24(colorTable[index]);
Unsafe.Add(ref rowRef, (uint)x) = TPixel.FromRgb24(colorTable[index]); }
} }
} }
} }
@ -652,8 +643,11 @@ internal sealed class GifDecoderCore : IImageDecoderInternals
// Skip the frame indices. Pixels length + mincode size. // Skip the frame indices. Pixels length + mincode size.
// The gif format does not tell us the length of the compressed data beforehand. // The gif format does not tell us the length of the compressed data beforehand.
int minCodeSize = stream.ReadByte(); int minCodeSize = stream.ReadByte();
using LzwDecoder lzwDecoder = new(this.configuration.MemoryAllocator, stream); if (LzwDecoder.IsValidMinCodeSize(minCodeSize))
lzwDecoder.SkipIndices(minCodeSize, this.imageDescriptor.Width * this.imageDescriptor.Height); {
using LzwDecoder lzwDecoder = new(this.configuration.MemoryAllocator, stream, minCodeSize);
lzwDecoder.SkipIndices(this.imageDescriptor.Width * this.imageDescriptor.Height);
}
ImageFrameMetadata currentFrame = new(); ImageFrameMetadata currentFrame = new();
frameMetadata.Add(currentFrame); frameMetadata.Add(currentFrame);

330
src/ImageSharp/Formats/Gif/LzwDecoder.cs
View File

@ -44,10 +44,29 @@ internal sealed class LzwDecoder : IDisposable
/// </summary> /// </summary>
private readonly IMemoryOwner<int> suffix; private readonly IMemoryOwner<int> suffix;
/// <summary>
/// The scratch buffer for reading data blocks.
/// </summary>
private readonly IMemoryOwner<byte> scratchBuffer;
/// <summary> /// <summary>
/// The pixel stack buffer. /// The pixel stack buffer.
/// </summary> /// </summary>
private readonly IMemoryOwner<int> pixelStack; private readonly IMemoryOwner<int> pixelStack;
private readonly int minCodeSize;
private readonly int clearCode;
private readonly int endCode;
private int code;
private int codeSize;
private int codeMask;
private int availableCode;
private int oldCode = NullCode;
private int bits;
private int top;
private int count;
private int bufferIndex;
private int data;
private int first;
/// <summary> /// <summary>
/// Initializes a new instance of the <see cref="LzwDecoder"/> class /// Initializes a new instance of the <see cref="LzwDecoder"/> class
@ -55,335 +74,277 @@ internal sealed class LzwDecoder : IDisposable
/// </summary> /// </summary>
/// <param name="memoryAllocator">The <see cref="MemoryAllocator"/> to use for buffer allocations.</param> /// <param name="memoryAllocator">The <see cref="MemoryAllocator"/> to use for buffer allocations.</param>
/// <param name="stream">The stream to read from.</param> /// <param name="stream">The stream to read from.</param>
/// <param name="minCodeSize">The minimum code size.</param>
/// <exception cref="ArgumentNullException"><paramref name="stream"/> is null.</exception> /// <exception cref="ArgumentNullException"><paramref name="stream"/> is null.</exception>
public LzwDecoder(MemoryAllocator memoryAllocator, BufferedReadStream stream) public LzwDecoder(MemoryAllocator memoryAllocator, BufferedReadStream stream, int minCodeSize)
{ {
this.stream = stream ?? throw new ArgumentNullException(nameof(stream)); this.stream = stream ?? throw new ArgumentNullException(nameof(stream));
this.prefix = memoryAllocator.Allocate<int>(MaxStackSize, AllocationOptions.Clean); this.prefix = memoryAllocator.Allocate<int>(MaxStackSize, AllocationOptions.Clean);
this.suffix = memoryAllocator.Allocate<int>(MaxStackSize, AllocationOptions.Clean); this.suffix = memoryAllocator.Allocate<int>(MaxStackSize, AllocationOptions.Clean);
this.pixelStack = memoryAllocator.Allocate<int>(MaxStackSize + 1, AllocationOptions.Clean); this.pixelStack = memoryAllocator.Allocate<int>(MaxStackSize + 1, AllocationOptions.Clean);
this.scratchBuffer = memoryAllocator.Allocate<byte>(byte.MaxValue, AllocationOptions.None);
this.minCodeSize = minCodeSize;
// Calculate the clear code. The value of the clear code is 2 ^ minCodeSize
this.clearCode = 1 << minCodeSize;
this.codeSize = minCodeSize + 1;
this.codeMask = (1 << this.codeSize) - 1;
this.endCode = this.clearCode + 1;
this.availableCode = this.clearCode + 2;
ref int suffixRef = ref MemoryMarshal.GetReference(this.suffix.GetSpan());
for (this.code = 0; this.code < this.clearCode; this.code++)
{
Unsafe.Add(ref suffixRef, (uint)this.code) = (byte)this.code;
}
} }
/// <summary> /// <summary>
/// Decodes and decompresses all pixel indices from the stream, assigning the pixel values to the buffer. /// Gets a value indicating whether the minimum code size is valid.
/// </summary> /// </summary>
/// <param name="minCodeSize">Minimum code size of the data.</param> /// <param name="minCodeSize">The minimum code size.</param>
/// <param name="pixels">The pixel array to decode to.</param> /// <returns>
public void DecodePixels(int minCodeSize, Buffer2D<byte> pixels) /// <see langword="true"/> if the minimum code size is valid; otherwise, <see langword="false"/>.
/// </returns>
public static bool IsValidMinCodeSize(int minCodeSize)
{ {
// Calculate the clear code. The value of the clear code is 2 ^ minCodeSize
int clearCode = 1 << minCodeSize;
// It is possible to specify a larger LZW minimum code size than the palette length in bits // It is possible to specify a larger LZW minimum code size than the palette length in bits
// which may leave a gap in the codes where no colors are assigned. // which may leave a gap in the codes where no colors are assigned.
// http://www.matthewflickinger.com/lab/whatsinagif/lzw_image_data.asp#lzw_compression // http://www.matthewflickinger.com/lab/whatsinagif/lzw_image_data.asp#lzw_compression
int clearCode = 1 << minCodeSize;
if (minCodeSize < 2 || minCodeSize > MaximumLzwBits || clearCode > MaxStackSize) if (minCodeSize < 2 || minCodeSize > MaximumLzwBits || clearCode > MaxStackSize)
{ {
// Don't attempt to decode the frame indices. // Don't attempt to decode the frame indices.
// Theoretically we could determine a min code size from the length of the provided // Theoretically we could determine a min code size from the length of the provided
// color palette but we won't bother since the image is most likely corrupted. // color palette but we won't bother since the image is most likely corrupted.
return; return false;
} }
// The resulting index table length. return true;
int width = pixels.Width; }
int height = pixels.Height;
int length = width * height;
int codeSize = minCodeSize + 1;
// Calculate the end code
int endCode = clearCode + 1;
// Calculate the available code.
int availableCode = clearCode + 2;
// Jillzhangs Code see: http://giflib.codeplex.com/
// Adapted from John Cristy's ImageMagick.
int code;
int oldCode = NullCode;
int codeMask = (1 << codeSize) - 1;
int bits = 0;
int top = 0;
int count = 0;
int bi = 0;
int xyz = 0;
int data = 0; /// <summary>
int first = 0; /// Decodes and decompresses all pixel indices for a single row from the stream, assigning the pixel values to the buffer.
/// </summary>
/// <param name="indices">The pixel indices array to decode to.</param>
public void DecodePixelRow(Span<byte> indices)
{
indices.Clear();
ref byte pixelsRowRef = ref MemoryMarshal.GetReference(indices);
ref int prefixRef = ref MemoryMarshal.GetReference(this.prefix.GetSpan()); ref int prefixRef = ref MemoryMarshal.GetReference(this.prefix.GetSpan());
ref int suffixRef = ref MemoryMarshal.GetReference(this.suffix.GetSpan()); ref int suffixRef = ref MemoryMarshal.GetReference(this.suffix.GetSpan());
ref int pixelStackRef = ref MemoryMarshal.GetReference(this.pixelStack.GetSpan()); ref int pixelStackRef = ref MemoryMarshal.GetReference(this.pixelStack.GetSpan());
Span<byte> buffer = this.scratchBuffer.GetSpan();
for (code = 0; code < clearCode; code++)
{
Unsafe.Add(ref suffixRef, (uint)code) = (byte)code;
}
Span<byte> buffer = stackalloc byte[byte.MaxValue];
int y = 0;
int x = 0; int x = 0;
int rowMax = width; int xyz = 0;
ref byte pixelsRowRef = ref MemoryMarshal.GetReference(pixels.DangerousGetRowSpan(y)); while (xyz < indices.Length)
while (xyz < length)
{ {
// Reset row reference. if (this.top == 0)
if (xyz == rowMax)
{
x = 0;
pixelsRowRef = ref MemoryMarshal.GetReference(pixels.DangerousGetRowSpan(++y));
rowMax = (y * width) + width;
}
if (top == 0)
{ {
if (bits < codeSize) if (this.bits < this.codeSize)
{ {
// Load bytes until there are enough bits for a code. // Load bytes until there are enough bits for a code.
if (count == 0) if (this.count == 0)
{ {
// Read a new data block. // Read a new data block.
count = this.ReadBlock(buffer); this.count = this.ReadBlock(buffer);
if (count == 0) if (this.count == 0)
{ {
break; break;
} }
bi = 0; this.bufferIndex = 0;
} }
data += buffer[bi] << bits; this.data += buffer[this.bufferIndex] << this.bits;
bits += 8; this.bits += 8;
bi++; this.bufferIndex++;
count--; this.count--;
continue; continue;
} }
// Get the next code // Get the next code
code = data & codeMask; this.code = this.data & this.codeMask;
data >>= codeSize; this.data >>= this.codeSize;
bits -= codeSize; this.bits -= this.codeSize;
// Interpret the code // Interpret the code
if (code > availableCode || code == endCode) if (this.code > this.availableCode || this.code == this.endCode)
{ {
break; break;
} }
if (code == clearCode) if (this.code == this.clearCode)
{ {
// Reset the decoder // Reset the decoder
codeSize = minCodeSize + 1; this.codeSize = this.minCodeSize + 1;
codeMask = (1 << codeSize) - 1; this.codeMask = (1 << this.codeSize) - 1;
availableCode = clearCode + 2; this.availableCode = this.clearCode + 2;
oldCode = NullCode; this.oldCode = NullCode;
continue; continue;
} }
if (oldCode == NullCode) if (this.oldCode == NullCode)
{ {
Unsafe.Add(ref pixelStackRef, (uint)top++) = Unsafe.Add(ref suffixRef, (uint)code); Unsafe.Add(ref pixelStackRef, (uint)this.top++) = Unsafe.Add(ref suffixRef, (uint)this.code);
oldCode = code; this.oldCode = this.code;
first = code; this.first = this.code;
continue; continue;
} }
int inCode = code; int inCode = this.code;
if (code == availableCode) if (this.code == this.availableCode)
{ {
Unsafe.Add(ref pixelStackRef, (uint)top++) = (byte)first; Unsafe.Add(ref pixelStackRef, (uint)this.top++) = (byte)this.first;
code = oldCode; this.code = this.oldCode;
} }
while (code > clearCode) while (this.code > this.clearCode)
{ {
Unsafe.Add(ref pixelStackRef, (uint)top++) = Unsafe.Add(ref suffixRef, (uint)code); Unsafe.Add(ref pixelStackRef, (uint)this.top++) = Unsafe.Add(ref suffixRef, (uint)this.code);
code = Unsafe.Add(ref prefixRef, (uint)code); this.code = Unsafe.Add(ref prefixRef, (uint)this.code);
} }
int suffixCode = Unsafe.Add(ref suffixRef, (uint)code); int suffixCode = Unsafe.Add(ref suffixRef, (uint)this.code);
first = suffixCode; this.first = suffixCode;
Unsafe.Add(ref pixelStackRef, (uint)top++) = suffixCode; Unsafe.Add(ref pixelStackRef, (uint)this.top++) = suffixCode;
// Fix for Gifs that have "deferred clear code" as per here : // Fix for Gifs that have "deferred clear code" as per here :
// https://bugzilla.mozilla.org/show_bug.cgi?id=55918 // https://bugzilla.mozilla.org/show_bug.cgi?id=55918
if (availableCode < MaxStackSize) if (this.availableCode < MaxStackSize)
{ {
Unsafe.Add(ref prefixRef, (uint)availableCode) = oldCode; Unsafe.Add(ref prefixRef, (uint)this.availableCode) = this.oldCode;
Unsafe.Add(ref suffixRef, (uint)availableCode) = first; Unsafe.Add(ref suffixRef, (uint)this.availableCode) = this.first;
availableCode++; this.availableCode++;
if (availableCode == codeMask + 1 && availableCode < MaxStackSize) if (this.availableCode == this.codeMask + 1 && this.availableCode < MaxStackSize)
{ {
codeSize++; this.codeSize++;
codeMask = (1 << codeSize) - 1; this.codeMask = (1 << this.codeSize) - 1;
} }
} }
oldCode = inCode; this.oldCode = inCode;
} }
// Pop a pixel off the pixel stack. // Pop a pixel off the pixel stack.
top--; this.top--;
// Clear missing pixels // Clear missing pixels
xyz++; xyz++;
Unsafe.Add(ref pixelsRowRef, (uint)x++) = (byte)Unsafe.Add(ref pixelStackRef, (uint)top); Unsafe.Add(ref pixelsRowRef, (uint)x++) = (byte)Unsafe.Add(ref pixelStackRef, (uint)this.top);
} }
} }
/// <summary> /// <summary>
/// Decodes and decompresses all pixel indices from the stream allowing skipping of the data. /// Decodes and decompresses all pixel indices from the stream allowing skipping of the data.
/// </summary> /// </summary>
/// <param name="minCodeSize">Minimum code size of the data.</param>
/// <param name="length">The resulting index table length.</param> /// <param name="length">The resulting index table length.</param>
public void SkipIndices(int minCodeSize, int length) public void SkipIndices(int length)
{ {
// Calculate the clear code. The value of the clear code is 2 ^ minCodeSize
int clearCode = 1 << minCodeSize;
// It is possible to specify a larger LZW minimum code size than the palette length in bits
// which may leave a gap in the codes where no colors are assigned.
// http://www.matthewflickinger.com/lab/whatsinagif/lzw_image_data.asp#lzw_compression
if (minCodeSize < 2 || minCodeSize > MaximumLzwBits || clearCode > MaxStackSize)
{
// Don't attempt to decode the frame indices.
// Theoretically we could determine a min code size from the length of the provided
// color palette but we won't bother since the image is most likely corrupted.
return;
}
int codeSize = minCodeSize + 1;
// Calculate the end code
int endCode = clearCode + 1;
// Calculate the available code.
int availableCode = clearCode + 2;
// Jillzhangs Code see: http://giflib.codeplex.com/
// Adapted from John Cristy's ImageMagick.
int code;
int oldCode = NullCode;
int codeMask = (1 << codeSize) - 1;
int bits = 0;
int top = 0;
int count = 0;
int bi = 0;
int xyz = 0;
int data = 0;
int first = 0;
ref int prefixRef = ref MemoryMarshal.GetReference(this.prefix.GetSpan()); ref int prefixRef = ref MemoryMarshal.GetReference(this.prefix.GetSpan());
ref int suffixRef = ref MemoryMarshal.GetReference(this.suffix.GetSpan()); ref int suffixRef = ref MemoryMarshal.GetReference(this.suffix.GetSpan());
ref int pixelStackRef = ref MemoryMarshal.GetReference(this.pixelStack.GetSpan()); ref int pixelStackRef = ref MemoryMarshal.GetReference(this.pixelStack.GetSpan());
Span<byte> buffer = this.scratchBuffer.GetSpan();
for (code = 0; code < clearCode; code++) int xyz = 0;
{
Unsafe.Add(ref suffixRef, (uint)code) = (byte)code;
}
Span<byte> buffer = stackalloc byte[byte.MaxValue];
while (xyz < length) while (xyz < length)
{ {
if (top == 0) if (this.top == 0)
{ {
if (bits < codeSize) if (this.bits < this.codeSize)
{ {
// Load bytes until there are enough bits for a code. // Load bytes until there are enough bits for a code.
if (count == 0) if (this.count == 0)
{ {
// Read a new data block. // Read a new data block.
count = this.ReadBlock(buffer); this.count = this.ReadBlock(buffer);
if (count == 0) if (this.count == 0)
{ {
break; break;
} }
bi = 0; this.bufferIndex = 0;
} }
data += buffer[bi] << bits; this.data += buffer[this.bufferIndex] << this.bits;
bits += 8; this.bits += 8;
bi++; this.bufferIndex++;
count--; this.count--;
continue; continue;
} }
// Get the next code // Get the next code
code = data & codeMask; this.code = this.data & this.codeMask;
data >>= codeSize; this.data >>= this.codeSize;
bits -= codeSize; this.bits -= this.codeSize;
// Interpret the code // Interpret the code
if (code > availableCode || code == endCode) if (this.code > this.availableCode || this.code == this.endCode)
{ {
break; break;
} }
if (code == clearCode) if (this.code == this.clearCode)
{ {
// Reset the decoder // Reset the decoder
codeSize = minCodeSize + 1; this.codeSize = this.minCodeSize + 1;
codeMask = (1 << codeSize) - 1; this.codeMask = (1 << this.codeSize) - 1;
availableCode = clearCode + 2; this.availableCode = this.clearCode + 2;
oldCode = NullCode; this.oldCode = NullCode;
continue; continue;
} }
if (oldCode == NullCode) if (this.oldCode == NullCode)
{ {
Unsafe.Add(ref pixelStackRef, (uint)top++) = Unsafe.Add(ref suffixRef, (uint)code); Unsafe.Add(ref pixelStackRef, (uint)this.top++) = Unsafe.Add(ref suffixRef, (uint)this.code);
oldCode = code; this.oldCode = this.code;
first = code; this.first = this.code;
continue; continue;
} }
int inCode = code; int inCode = this.code;
if (code == availableCode) if (this.code == this.availableCode)
{ {
Unsafe.Add(ref pixelStackRef, (uint)top++) = (byte)first; Unsafe.Add(ref pixelStackRef, (uint)this.top++) = (byte)this.first;
code = oldCode; this.code = this.oldCode;
} }
while (code > clearCode) while (this.code > this.clearCode)
{ {
Unsafe.Add(ref pixelStackRef, (uint)top++) = Unsafe.Add(ref suffixRef, (uint)code); Unsafe.Add(ref pixelStackRef, (uint)this.top++) = Unsafe.Add(ref suffixRef, (uint)this.code);
code = Unsafe.Add(ref prefixRef, (uint)code); this.code = Unsafe.Add(ref prefixRef, (uint)this.code);
} }
int suffixCode = Unsafe.Add(ref suffixRef, (uint)code); int suffixCode = Unsafe.Add(ref suffixRef, (uint)this.code);
first = suffixCode; this.first = suffixCode;
Unsafe.Add(ref pixelStackRef, (uint)top++) = suffixCode; Unsafe.Add(ref pixelStackRef, (uint)this.top++) = suffixCode;
// Fix for Gifs that have "deferred clear code" as per here : // Fix for Gifs that have "deferred clear code" as per here :
// https://bugzilla.mozilla.org/show_bug.cgi?id=55918 // https://bugzilla.mozilla.org/show_bug.cgi?id=55918
if (availableCode < MaxStackSize) if (this.availableCode < MaxStackSize)
{ {
Unsafe.Add(ref prefixRef, (uint)availableCode) = oldCode; Unsafe.Add(ref prefixRef, (uint)this.availableCode) = this.oldCode;
Unsafe.Add(ref suffixRef, (uint)availableCode) = first; Unsafe.Add(ref suffixRef, (uint)this.availableCode) = this.first;
availableCode++; this.availableCode++;
if (availableCode == codeMask + 1 && availableCode < MaxStackSize) if (this.availableCode == this.codeMask + 1 && this.availableCode < MaxStackSize)
{ {
codeSize++; this.codeSize++;
codeMask = (1 << codeSize) - 1; this.codeMask = (1 << this.codeSize) - 1;
} }
} }
oldCode = inCode; this.oldCode = inCode;
} }
// Pop a pixel off the pixel stack. // Pop a pixel off the pixel stack.
top--; this.top--;
// Clear missing pixels // Clear missing pixels
xyz++; xyz++;
@ -419,5 +380,6 @@ internal sealed class LzwDecoder : IDisposable
this.prefix.Dispose(); this.prefix.Dispose();
this.suffix.Dispose(); this.suffix.Dispose();
this.pixelStack.Dispose(); this.pixelStack.Dispose();
this.scratchBuffer.Dispose();
} }
} }

2
src/ImageSharp/Formats/Jpeg/Components/Quantization.cs
View File

@ -146,7 +146,7 @@ internal static class Quantization
quality = (int)Math.Round(5000.0 / sumPercent); quality = (int)Math.Round(5000.0 / sumPercent);
} }
return quality; return Numerics.Clamp(quality, MinQualityFactor, MaxQualityFactor);
} }
/// <summary> /// <summary>

11
tests/ImageSharp.Tests/Formats/Gif/GifDecoderTests.cs
View File

@ -204,6 +204,17 @@ public class GifDecoderTests
image.CompareToReferenceOutputMultiFrame(provider, ImageComparer.Exact); image.CompareToReferenceOutputMultiFrame(provider, ImageComparer.Exact);
} }
// https://github.com/SixLabors/ImageSharp/issues/2758
[Theory]
[WithFile(TestImages.Gif.Issues.Issue2758, PixelTypes.Rgba32)]
public void Issue2758_BadDescriptorDimensions<TPixel>(TestImageProvider<TPixel> provider)
where TPixel : unmanaged, IPixel<TPixel>
{
using Image<TPixel> image = provider.GetImage();
image.DebugSaveMultiFrame(provider);
image.CompareToReferenceOutputMultiFrame(provider, ImageComparer.Exact);
}
// https://github.com/SixLabors/ImageSharp/issues/405 // https://github.com/SixLabors/ImageSharp/issues/405
[Theory] [Theory]
[WithFile(TestImages.Gif.Issues.BadAppExtLength, PixelTypes.Rgba32)] [WithFile(TestImages.Gif.Issues.BadAppExtLength, PixelTypes.Rgba32)]

28
tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.Metadata.cs
View File

@ -8,6 +8,7 @@ using SixLabors.ImageSharp.Metadata;
using SixLabors.ImageSharp.Metadata.Profiles.Exif; using SixLabors.ImageSharp.Metadata.Profiles.Exif;
using SixLabors.ImageSharp.Metadata.Profiles.Icc; using SixLabors.ImageSharp.Metadata.Profiles.Icc;
using SixLabors.ImageSharp.PixelFormats; using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;
using SixLabors.ImageSharp.Tests.TestUtilities; using SixLabors.ImageSharp.Tests.TestUtilities;
// ReSharper disable InconsistentNaming // ReSharper disable InconsistentNaming
@ -438,6 +439,33 @@ public partial class JpegDecoderTests
Assert.Equal(expectedComment, metadata.Comments.ElementAtOrDefault(0).ToString()); Assert.Equal(expectedComment, metadata.Comments.ElementAtOrDefault(0).ToString());
image.DebugSave(provider); image.DebugSave(provider);
image.CompareToOriginal(provider); image.CompareToOriginal(provider);
}
// https://github.com/SixLabors/ImageSharp/issues/2758
[Theory]
[WithFile(TestImages.Jpeg.Issues.Issue2758, PixelTypes.L8)]
public void Issue2758_DecodeWorks<TPixel>(TestImageProvider<TPixel> provider)
where TPixel : unmanaged, IPixel<TPixel>
{
using Image<TPixel> image = provider.GetImage(JpegDecoder.Instance);
Assert.Equal(59787, image.Width);
Assert.Equal(511, image.Height);
JpegMetadata meta = image.Metadata.GetJpegMetadata();
// Quality determination should be between 1-100.
Assert.Equal(15, meta.LuminanceQuality);
Assert.Equal(1, meta.ChrominanceQuality);
// We want to test the encoder to ensure the determined values can be encoded but not by encoding
// the full size image as it would be too slow.
// We will crop the image to a smaller size and then encode it.
image.Mutate(x => x.Crop(new(0, 0, 100, 100)));
using MemoryStream ms = new();
image.Save(ms, new JpegEncoder());
} }
private static void VerifyEncodedStrings(ExifProfile exif) private static void VerifyEncodedStrings(ExifProfile exif)

2
tests/ImageSharp.Tests/TestImages.cs
View File

@ -321,6 +321,7 @@ public static class TestImages
public const string Issue2517 = "Jpg/issues/issue2517-bad-d7.jpg"; public const string Issue2517 = "Jpg/issues/issue2517-bad-d7.jpg";
public const string Issue2067_CommentMarker = "Jpg/issues/issue-2067-comment.jpg"; public const string Issue2067_CommentMarker = "Jpg/issues/issue-2067-comment.jpg";
public const string Issue2638 = "Jpg/issues/Issue2638.jpg"; public const string Issue2638 = "Jpg/issues/Issue2638.jpg";
public const string Issue2758 = "Jpg/issues/issue-2758.jpg";
public static class Fuzz public static class Fuzz
{ {
@ -531,6 +532,7 @@ public static class TestImages
public const string Issue2450_A = "Gif/issues/issue_2450.gif"; public const string Issue2450_A = "Gif/issues/issue_2450.gif";
public const string Issue2450_B = "Gif/issues/issue_2450_2.gif"; public const string Issue2450_B = "Gif/issues/issue_2450_2.gif";
public const string Issue2198 = "Gif/issues/issue_2198.gif"; public const string Issue2198 = "Gif/issues/issue_2198.gif";
public const string Issue2758 = "Gif/issues/issue_2758.gif";
} }
public static readonly string[] Animated = public static readonly string[] Animated =

4
tests/Images/External/ReferenceOutput/GifDecoderTests/Issue2012BadMinCode_Rgba32_issue2012_drona1.png
View File

@ -1,3 +1,3 @@
version https://git-lfs.github.com/spec/v1 version https://git-lfs.github.com/spec/v1
oid sha256:a3a24c066895fd3a76649da376485cbc1912d6a3ae15369575f523e66364b3b6 oid sha256:588d055a93c7b4fdb62e8b77f3ae08753a9e8990151cb0523f5e761996189b70
size 141563 size 142244

3
tests/Images/External/ReferenceOutput/GifDecoderTests/Issue2758_BadDescriptorDimensions_Rgba32_issue_2758.gif/00.png
View File

@ -0,0 +1,3 @@
version https://git-lfs.github.com/spec/v1
oid sha256:4f39b23217f1d095eeb8eed5ccea36be813c307a60ef4b1942e9f74028451c38
size 81944

3
tests/Images/External/ReferenceOutput/GifDecoderTests/Issue2758_BadDescriptorDimensions_Rgba32_issue_2758.gif/01.png
View File

@ -0,0 +1,3 @@
version https://git-lfs.github.com/spec/v1
oid sha256:4f39b23217f1d095eeb8eed5ccea36be813c307a60ef4b1942e9f74028451c38
size 81944

4
tests/Images/External/ReferenceOutput/GifDecoderTests/IssueTooLargeLzwBits_Rgba32_issue_2743.gif/07.png
View File

@ -1,3 +1,3 @@
version https://git-lfs.github.com/spec/v1 version https://git-lfs.github.com/spec/v1
oid sha256:489642f0c81fd12e97007fe6feb11b0e93e351199a922ce038069a3782ad0722 oid sha256:5016a323018f09e292165ad5392d82dcbad5e79c2b6b93aff3322dffff80b309
size 135 size 126

3
tests/Images/Input/Gif/issues/issue_2758.gif
View File

@ -0,0 +1,3 @@
version https://git-lfs.github.com/spec/v1
oid sha256:13e9374181c7536d1d2ecb514753a5290c0ec06234ca079c6c8c8a832586b668
size 199

3
tests/Images/Input/Jpg/issues/issue-2758.jpg
View File

@ -0,0 +1,3 @@
version https://git-lfs.github.com/spec/v1
oid sha256:f32a238b57b7073f7442f8ae7efd6ba3ae4cda30d57e6666fb8a1eaa27108558
size 1412
Write Preview
Loading…
Cancel
Save