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Add identify API

pull/525/head
James Jackson-South 8 years ago
parent
e927e307d8
commit
6c8da2bf9e
3 changed files with 124 additions and 61 deletions
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  1. 2
      src/ImageSharp/Formats/Jpeg/GolangPort/OrigJpegDecoder.cs
  2. 13
      src/ImageSharp/Formats/Jpeg/PdfJsPort/PdfJsJpegDecoder.cs
  3. 170
      src/ImageSharp/Formats/Jpeg/PdfJsPort/PdfJsJpegDecoderCore.cs

2
src/ImageSharp/Formats/Jpeg/GolangPort/OrigJpegDecoder.cs
View File

@ -31,7 +31,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
/// <inheritdoc/> /// <inheritdoc/>
public IImageInfo Identify(Configuration configuration, Stream stream) public IImageInfo Identify(Configuration configuration, Stream stream)
{ {
Guard.NotNull(stream, "stream"); Guard.NotNull(stream, nameof(stream));
using (var decoder = new OrigJpegDecoderCore(configuration, this)) using (var decoder = new OrigJpegDecoderCore(configuration, this))
{ {

13
src/ImageSharp/Formats/Jpeg/PdfJsPort/PdfJsJpegDecoder.cs
View File

@ -9,7 +9,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// <summary> /// <summary>
/// Image decoder for generating an image out of a jpg stream. /// Image decoder for generating an image out of a jpg stream.
/// </summary> /// </summary>
internal sealed class PdfJsJpegDecoder : IImageDecoder, IJpegDecoderOptions internal sealed class PdfJsJpegDecoder : IImageDecoder, IJpegDecoderOptions, IImageInfoDetector
{ {
/// <summary> /// <summary>
/// Gets or sets a value indicating whether the metadata should be ignored when the image is being decoded. /// Gets or sets a value indicating whether the metadata should be ignored when the image is being decoded.
@ -27,5 +27,16 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
return decoder.Decode<TPixel>(stream); return decoder.Decode<TPixel>(stream);
} }
} }
/// <inheritdoc/>
public IImageInfo Identify(Configuration configuration, Stream stream)
{
Guard.NotNull(stream, nameof(stream));
using (var decoder = new PdfJsJpegDecoderCore(configuration, this))
{
return decoder.Identify(stream);
}
}
} }
} }

170
src/ImageSharp/Formats/Jpeg/PdfJsPort/PdfJsJpegDecoderCore.cs
View File

@ -24,6 +24,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// </summary> /// </summary>
internal sealed class PdfJsJpegDecoderCore : IDisposable internal sealed class PdfJsJpegDecoderCore : IDisposable
{ {
/// <summary>
/// The only supported precision
/// </summary>
public const int SupportedPrecision = 8;
#pragma warning disable SA1401 // Fields should be private #pragma warning disable SA1401 // Fields should be private
/// <summary> /// <summary>
/// The global configuration /// The global configuration
@ -103,6 +108,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// </summary> /// </summary>
public int NumberOfComponents { get; private set; } public int NumberOfComponents { get; private set; }
/// <summary>
/// Gets the color depth, in number of bits per pixel.
/// </summary>
public int BitsPerPixel => this.NumberOfComponents * SupportedPrecision;
/// <summary> /// <summary>
/// Gets the input stream. /// Gets the input stream.
/// </summary> /// </summary>
@ -113,6 +123,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// </summary> /// </summary>
public bool IgnoreMetadata { get; } public bool IgnoreMetadata { get; }
/// <summary>
/// Gets the <see cref="ImageMetaData"/> decoded by this decoder instance.
/// </summary>
public ImageMetaData MetaData { get; private set; }
/// <summary> /// <summary>
/// Finds the next file marker within the byte stream. /// Finds the next file marker within the byte stream.
/// </summary> /// </summary>
@ -158,55 +173,36 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
public Image<TPixel> Decode<TPixel>(Stream stream) public Image<TPixel> Decode<TPixel>(Stream stream)
where TPixel : struct, IPixel<TPixel> where TPixel : struct, IPixel<TPixel>
{ {
ImageMetaData metadata = this.ParseStream(stream); this.ParseStream(stream);
this.QuantizeAndInverseAllComponents(); this.QuantizeAndInverseAllComponents();
var image = new Image<TPixel>(this.configuration, this.ImageWidth, this.ImageHeight, metadata); var image = new Image<TPixel>(this.configuration, this.ImageWidth, this.ImageHeight, this.MetaData);
this.FillPixelData(image.Frames.RootFrame); this.FillPixelData(image.Frames.RootFrame);
this.AssignResolution(image); this.AssignResolution();
return image; return image;
} }
/// <inheritdoc/> /// <summary>
public void Dispose() /// Reads the raw image information from the specified stream.
{ /// </summary>
this.Frame?.Dispose(); /// <param name="stream">The <see cref="Stream"/> containing image data.</param>
this.components?.Dispose(); public IImageInfo Identify(Stream stream)
this.quantizationTables?.Dispose();
this.pixelArea.Dispose();
// Set large fields to null.
this.Frame = null;
this.components = null;
this.quantizationTables = null;
this.dcHuffmanTables = null;
this.acHuffmanTables = null;
}
internal ImageMetaData ParseStream(Stream stream)
{
this.InputStream = stream;
var metadata = new ImageMetaData();
this.ParseStream(metadata, false);
return metadata;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static int GetBlockBufferOffset(ref PdfJsComponent component, int row, int col)
{ {
return 64 * (((component.BlocksPerLine + 1) * row) + col); this.ParseStream(stream, true);
this.AssignResolution();
return new ImageInfo(new PixelTypeInfo(this.BitsPerPixel), this.ImageWidth, this.ImageHeight, this.MetaData);
} }
/// <summary> /// <summary>
/// Parses the input stream for file markers /// Parses the input stream for file markers
/// </summary> /// </summary>
/// <param name="metaData">Contains the metadata for an image</param> /// <param name="stream">The input stream</param>
/// <param name="metadataOnly">Whether to decode metadata only.</param> /// <param name="metadataOnly">Whether to decode metadata only.</param>
private void ParseStream(ImageMetaData metaData, bool metadataOnly) public void ParseStream(Stream stream, bool metadataOnly = false)
{ {
// TODO: metadata only logic this.MetaData = new ImageMetaData();
this.InputStream = stream;
// Check for the Start Of Image marker. // Check for the Start Of Image marker.
var fileMarker = new PdfJsFileMarker(this.ReadUint16(), 0); var fileMarker = new PdfJsFileMarker(this.ReadUint16(), 0);
if (fileMarker.Marker != PdfJsJpegConstants.Markers.SOI) if (fileMarker.Marker != PdfJsJpegConstants.Markers.SOI)
@ -233,11 +229,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
break; break;
case PdfJsJpegConstants.Markers.APP1: case PdfJsJpegConstants.Markers.APP1:
this.ProcessApp1Marker(remaining, metaData); this.ProcessApp1Marker(remaining);
break; break;
case PdfJsJpegConstants.Markers.APP2: case PdfJsJpegConstants.Markers.APP2:
this.ProcessApp2Marker(remaining, metaData); this.ProcessApp2Marker(remaining);
break; break;
case PdfJsJpegConstants.Markers.APP3: case PdfJsJpegConstants.Markers.APP3:
case PdfJsJpegConstants.Markers.APP4: case PdfJsJpegConstants.Markers.APP4:
@ -263,24 +259,58 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
break; break;
case PdfJsJpegConstants.Markers.DQT: case PdfJsJpegConstants.Markers.DQT:
this.ProcessDefineQuantizationTablesMarker(remaining); if (metadataOnly)
{
this.InputStream.Skip(remaining);
}
else
{
this.ProcessDefineQuantizationTablesMarker(remaining);
}
break; break;
case PdfJsJpegConstants.Markers.SOF0: case PdfJsJpegConstants.Markers.SOF0:
case PdfJsJpegConstants.Markers.SOF1: case PdfJsJpegConstants.Markers.SOF1:
case PdfJsJpegConstants.Markers.SOF2: case PdfJsJpegConstants.Markers.SOF2:
this.ProcessStartOfFrameMarker(remaining, fileMarker); this.ProcessStartOfFrameMarker(remaining, fileMarker);
if (metadataOnly && !this.jFif.Equals(default))
{
this.InputStream.Skip(remaining);
}
break; break;
case PdfJsJpegConstants.Markers.DHT: case PdfJsJpegConstants.Markers.DHT:
this.ProcessDefineHuffmanTablesMarker(remaining); if (metadataOnly)
{
this.InputStream.Skip(remaining);
}
else
{
this.ProcessDefineHuffmanTablesMarker(remaining);
}
break; break;
case PdfJsJpegConstants.Markers.DRI: case PdfJsJpegConstants.Markers.DRI:
this.ProcessDefineRestartIntervalMarker(remaining); if (metadataOnly)
{
this.InputStream.Skip(remaining);
}
else
{
this.ProcessDefineRestartIntervalMarker(remaining);
}
break; break;
case PdfJsJpegConstants.Markers.SOS: case PdfJsJpegConstants.Markers.SOS:
if (metadataOnly)
{
return;
}
this.ProcessStartOfScanMarker(); this.ProcessStartOfScanMarker();
break; break;
} }
@ -312,6 +342,28 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
this.NumberOfComponents = this.components.Components.Length; this.NumberOfComponents = this.components.Components.Length;
} }
/// <inheritdoc/>
public void Dispose()
{
this.Frame?.Dispose();
this.components?.Dispose();
this.quantizationTables?.Dispose();
this.pixelArea.Dispose();
// Set large fields to null.
this.Frame = null;
this.components = null;
this.quantizationTables = null;
this.dcHuffmanTables = null;
this.acHuffmanTables = null;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static int GetBlockBufferOffset(ref PdfJsComponent component, int row, int col)
{
return 64 * (((component.BlocksPerLine + 1) * row) + col);
}
internal void QuantizeAndInverseAllComponents() internal void QuantizeAndInverseAllComponents()
{ {
for (int i = 0; i < this.components.Components.Length; i++) for (int i = 0; i < this.components.Components.Length; i++)
@ -373,31 +425,28 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// <summary> /// <summary>
/// Assigns the horizontal and vertical resolution to the image if it has a JFIF header or EXIF metadata. /// Assigns the horizontal and vertical resolution to the image if it has a JFIF header or EXIF metadata.
/// </summary> /// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam> private void AssignResolution()
/// <param name="image">The image to assign the resolution to.</param>
private void AssignResolution<TPixel>(Image<TPixel> image)
where TPixel : struct, IPixel<TPixel>
{ {
if (this.isExif) if (this.isExif)
{ {
double horizontalValue = image.MetaData.ExifProfile.TryGetValue(ExifTag.XResolution, out ExifValue horizontalTag) double horizontalValue = this.MetaData.ExifProfile.TryGetValue(ExifTag.XResolution, out ExifValue horizontalTag)
? ((Rational)horizontalTag.Value).ToDouble() ? ((Rational)horizontalTag.Value).ToDouble()
: 0; : 0;
double verticalValue = image.MetaData.ExifProfile.TryGetValue(ExifTag.YResolution, out ExifValue verticalTag) double verticalValue = this.MetaData.ExifProfile.TryGetValue(ExifTag.YResolution, out ExifValue verticalTag)
? ((Rational)verticalTag.Value).ToDouble() ? ((Rational)verticalTag.Value).ToDouble()
: 0; : 0;
if (horizontalValue > 0 && verticalValue > 0) if (horizontalValue > 0 && verticalValue > 0)
{ {
image.MetaData.HorizontalResolution = horizontalValue; this.MetaData.HorizontalResolution = horizontalValue;
image.MetaData.VerticalResolution = verticalValue; this.MetaData.VerticalResolution = verticalValue;
} }
} }
else if (this.jFif.XDensity > 0 && this.jFif.YDensity > 0) else if (this.jFif.XDensity > 0 && this.jFif.YDensity > 0)
{ {
image.MetaData.HorizontalResolution = this.jFif.XDensity; this.MetaData.HorizontalResolution = this.jFif.XDensity;
image.MetaData.VerticalResolution = this.jFif.YDensity; this.MetaData.VerticalResolution = this.jFif.YDensity;
} }
} }
@ -430,8 +479,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// Processes the App1 marker retrieving any stored metadata /// Processes the App1 marker retrieving any stored metadata
/// </summary> /// </summary>
/// <param name="remaining">The remaining bytes in the segment block.</param> /// <param name="remaining">The remaining bytes in the segment block.</param>
/// <param name="metadata">The image.</param> private void ProcessApp1Marker(int remaining)
private void ProcessApp1Marker(int remaining, ImageMetaData metadata)
{ {
if (remaining < 6 || this.IgnoreMetadata) if (remaining < 6 || this.IgnoreMetadata)
{ {
@ -451,7 +499,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
profile[5] == PdfJsJpegConstants.Markers.Exif.Null) profile[5] == PdfJsJpegConstants.Markers.Exif.Null)
{ {
this.isExif = true; this.isExif = true;
metadata.ExifProfile = new ExifProfile(profile); this.MetaData.ExifProfile = new ExifProfile(profile);
} }
} }
@ -459,8 +507,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// Processes the App2 marker retrieving any stored ICC profile information /// Processes the App2 marker retrieving any stored ICC profile information
/// </summary> /// </summary>
/// <param name="remaining">The remaining bytes in the segment block.</param> /// <param name="remaining">The remaining bytes in the segment block.</param>
/// <param name="metadata">The image.</param> private void ProcessApp2Marker(int remaining)
private void ProcessApp2Marker(int remaining, ImageMetaData metadata)
{ {
// Length is 14 though we only need to check 12. // Length is 14 though we only need to check 12.
const int Icclength = 14; const int Icclength = 14;
@ -490,13 +537,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
byte[] profile = new byte[remaining]; byte[] profile = new byte[remaining];
this.InputStream.Read(profile, 0, remaining); this.InputStream.Read(profile, 0, remaining);
if (metadata.IccProfile == null) if (this.MetaData.IccProfile == null)
{ {
metadata.IccProfile = new IccProfile(profile); this.MetaData.IccProfile = new IccProfile(profile);
} }
else else
{ {
metadata.IccProfile.Extend(profile); this.MetaData.IccProfile.Extend(profile);
} }
} }
else else
@ -619,6 +666,12 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
this.InputStream.Read(this.temp, 0, remaining); this.InputStream.Read(this.temp, 0, remaining);
// We only support 8-bit precision.
if (this.temp[0] != SupportedPrecision)
{
throw new ImageFormatException("Only 8-Bit precision supported.");
}
this.Frame = new PdfJsFrame this.Frame = new PdfJsFrame
{ {
Extended = frameMarker.Marker == PdfJsJpegConstants.Markers.SOF1, Extended = frameMarker.Marker == PdfJsJpegConstants.Markers.SOF1,
@ -791,7 +844,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
int blocksPerLine = component.BlocksPerLine; int blocksPerLine = component.BlocksPerLine;
int blocksPerColumn = component.BlocksPerColumn; int blocksPerColumn = component.BlocksPerColumn;
using (IBuffer<short> computationBuffer = this.configuration.MemoryManager.Allocate<short>(64, true)) using (IBuffer<short> computationBuffer = this.configuration.MemoryManager.Allocate<short>(64, true))
using (IBuffer<short> multiplicationBuffer = this.configuration.MemoryManager.Allocate<short>(64, true))
{ {
ref short quantizationTableRef = ref MemoryMarshal.GetReference(this.quantizationTables.Tables.GetRowSpan(frameComponent.QuantizationTableIndex)); ref short quantizationTableRef = ref MemoryMarshal.GetReference(this.quantizationTables.Tables.GetRowSpan(frameComponent.QuantizationTableIndex));
ref short computationBufferSpan = ref MemoryMarshal.GetReference(computationBuffer.Span); ref short computationBufferSpan = ref MemoryMarshal.GetReference(computationBuffer.Span);

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