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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/>
public IImageInfo Identify(Configuration configuration, Stream stream)
{
Guard.NotNull(stream, "stream");
Guard.NotNull(stream, nameof(stream));
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>
/// Image decoder for generating an image out of a jpg stream.
/// </summary>
internal sealed class PdfJsJpegDecoder : IImageDecoder, IJpegDecoderOptions
internal sealed class PdfJsJpegDecoder : IImageDecoder, IJpegDecoderOptions, IImageInfoDetector
{
/// <summary>
/// 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);
}
}
/// <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>
internal sealed class PdfJsJpegDecoderCore : IDisposable
{
/// <summary>
/// The only supported precision
/// </summary>
public const int SupportedPrecision = 8;
#pragma warning disable SA1401 // Fields should be private
/// <summary>
/// The global configuration
@ -103,6 +108,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// </summary>
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>
/// Gets the input stream.
/// </summary>
@ -113,6 +123,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// </summary>
public bool IgnoreMetadata { get; }
/// <summary>
/// Gets the <see cref="ImageMetaData"/> decoded by this decoder instance.
/// </summary>
public ImageMetaData MetaData { get; private set; }
/// <summary>
/// Finds the next file marker within the byte stream.
/// </summary>
@ -158,55 +173,36 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
public Image<TPixel> Decode<TPixel>(Stream stream)
where TPixel : struct, IPixel<TPixel>
{
ImageMetaData metadata = this.ParseStream(stream);
this.ParseStream(stream);
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.AssignResolution(image);
this.AssignResolution();
return image;
}
/// <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;
}
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)
/// <summary>
/// Reads the raw image information from the specified stream.
/// </summary>
/// <param name="stream">The <see cref="Stream"/> containing image data.</param>
public IImageInfo Identify(Stream stream)
{
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>
/// Parses the input stream for file markers
/// </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>
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.
var fileMarker = new PdfJsFileMarker(this.ReadUint16(), 0);
if (fileMarker.Marker != PdfJsJpegConstants.Markers.SOI)
@ -233,11 +229,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
break;
case PdfJsJpegConstants.Markers.APP1:
this.ProcessApp1Marker(remaining, metaData);
this.ProcessApp1Marker(remaining);
break;
case PdfJsJpegConstants.Markers.APP2:
this.ProcessApp2Marker(remaining, metaData);
this.ProcessApp2Marker(remaining);
break;
case PdfJsJpegConstants.Markers.APP3:
case PdfJsJpegConstants.Markers.APP4:
@ -263,24 +259,58 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
break;
case PdfJsJpegConstants.Markers.DQT:
this.ProcessDefineQuantizationTablesMarker(remaining);
if (metadataOnly)
{
this.InputStream.Skip(remaining);
}
else
{
this.ProcessDefineQuantizationTablesMarker(remaining);
}
break;
case PdfJsJpegConstants.Markers.SOF0:
case PdfJsJpegConstants.Markers.SOF1:
case PdfJsJpegConstants.Markers.SOF2:
this.ProcessStartOfFrameMarker(remaining, fileMarker);
if (metadataOnly && !this.jFif.Equals(default))
{
this.InputStream.Skip(remaining);
}
break;
case PdfJsJpegConstants.Markers.DHT:
this.ProcessDefineHuffmanTablesMarker(remaining);
if (metadataOnly)
{
this.InputStream.Skip(remaining);
}
else
{
this.ProcessDefineHuffmanTablesMarker(remaining);
}
break;
case PdfJsJpegConstants.Markers.DRI:
this.ProcessDefineRestartIntervalMarker(remaining);
if (metadataOnly)
{
this.InputStream.Skip(remaining);
}
else
{
this.ProcessDefineRestartIntervalMarker(remaining);
}
break;
case PdfJsJpegConstants.Markers.SOS:
if (metadataOnly)
{
return;
}
this.ProcessStartOfScanMarker();
break;
}
@ -312,6 +342,28 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
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()
{
for (int i = 0; i < this.components.Components.Length; i++)
@ -373,31 +425,28 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// <summary>
/// Assigns the horizontal and vertical resolution to the image if it has a JFIF header or EXIF metadata.
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="image">The image to assign the resolution to.</param>
private void AssignResolution<TPixel>(Image<TPixel> image)
where TPixel : struct, IPixel<TPixel>
private void AssignResolution()
{
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()
: 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()
: 0;
if (horizontalValue > 0 && verticalValue > 0)
{
image.MetaData.HorizontalResolution = horizontalValue;
image.MetaData.VerticalResolution = verticalValue;
this.MetaData.HorizontalResolution = horizontalValue;
this.MetaData.VerticalResolution = verticalValue;
}
}
else if (this.jFif.XDensity > 0 && this.jFif.YDensity > 0)
{
image.MetaData.HorizontalResolution = this.jFif.XDensity;
image.MetaData.VerticalResolution = this.jFif.YDensity;
this.MetaData.HorizontalResolution = this.jFif.XDensity;
this.MetaData.VerticalResolution = this.jFif.YDensity;
}
}
@ -430,8 +479,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
/// Processes the App1 marker retrieving any stored metadata
/// </summary>
/// <param name="remaining">The remaining bytes in the segment block.</param>
/// <param name="metadata">The image.</param>
private void ProcessApp1Marker(int remaining, ImageMetaData metadata)
private void ProcessApp1Marker(int remaining)
{
if (remaining < 6 || this.IgnoreMetadata)
{
@ -451,7 +499,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
profile[5] == PdfJsJpegConstants.Markers.Exif.Null)
{
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
/// </summary>
/// <param name="remaining">The remaining bytes in the segment block.</param>
/// <param name="metadata">The image.</param>
private void ProcessApp2Marker(int remaining, ImageMetaData metadata)
private void ProcessApp2Marker(int remaining)
{
// Length is 14 though we only need to check 12.
const int Icclength = 14;
@ -490,13 +537,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
byte[] profile = new byte[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
{
metadata.IccProfile.Extend(profile);
this.MetaData.IccProfile.Extend(profile);
}
}
else
@ -619,6 +666,12 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
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
{
Extended = frameMarker.Marker == PdfJsJpegConstants.Markers.SOF1,
@ -791,7 +844,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort
int blocksPerLine = component.BlocksPerLine;
int blocksPerColumn = component.BlocksPerColumn;
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 computationBufferSpan = ref MemoryMarshal.GetReference(computationBuffer.Span);

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