public Bitmap Load()
{
if (this.ImageWidth == 0 || this.ImageHeight == 0)
{
JpegThrowHelper.ThrowInvalidImageDimensions(this.ImageWidth, this.ImageHeight);
}
var buffer = new Buffer2D <Vector4>(MemoryGroup <Vector4> .Allocate(this.ImageWidth * this.ImageHeight, this.ImageWidth), this.ImageWidth, this.ImageHeight);
using (var postProcessor = new JpegImagePostProcessor(this.RawData))
{
postProcessor.PostProcess(buffer, new System.Threading.CancellationToken());
}
var bitmap = new Bitmap(this.ImageWidth, this.ImageHeight);
for (int y = 0; y < bitmap.Height; y++)
{
for (int x = 0; x < bitmap.Width; x++)
{
ref var p = ref buffer[x, y];
bitmap.PixelBufferView[x, y] = new Pixel()
{
A = p.W,
B = p.Z,
G = p.Y,
R = p.X
};
}
}
/// <summary>
/// Parses the input stream for file markers
/// </summary>
/// <param name="stream">The input stream</param>
/// <param name="metadataOnly">Whether to decode metadata only.</param>
/// <param name="cancellationToken">The token to monitor cancellation.</param>
public void ParseStream(BufferedReadStream stream, bool metadataOnly = false, CancellationToken cancellationToken = default)
{
this.Metadata = new ImageMetadata();
// Check for the Start Of Image marker.
stream.Read(this.markerBuffer, 0, 2);
var fileMarker = new JpegFileMarker(this.markerBuffer[1], 0);
if (fileMarker.Marker != JpegConstants.Markers.SOI)
{
JpegThrowHelper.ThrowInvalidImageContentException("Missing SOI marker.");
}
stream.Read(this.markerBuffer, 0, 2);
byte marker = this.markerBuffer[1];
fileMarker = new JpegFileMarker(marker, (int)stream.Position - 2);
this.QuantizationTables = new Block8x8F[4];
// Only assign what we need
if (!metadataOnly)
{
const int maxTables = 4;
this.dcHuffmanTables = new HuffmanTable[maxTables];
this.acHuffmanTables = new HuffmanTable[maxTables];
}
// Break only when we discover a valid EOI marker.
// https://github.com/SixLabors/ImageSharp/issues/695
while (fileMarker.Marker != JpegConstants.Markers.EOI ||
(fileMarker.Marker == JpegConstants.Markers.EOI && fileMarker.Invalid))
{
cancellationToken.ThrowIfCancellationRequested();
if (!fileMarker.Invalid)
{
// Get the marker length
int remaining = this.ReadUint16(stream) - 2;
switch (fileMarker.Marker)
{
case JpegConstants.Markers.SOF0:
case JpegConstants.Markers.SOF1:
case JpegConstants.Markers.SOF2:
this.ProcessStartOfFrameMarker(stream, remaining, fileMarker, metadataOnly);
break;
case JpegConstants.Markers.SOS:
if (!metadataOnly)
{
this.ProcessStartOfScanMarker(stream, cancellationToken);
break;
}
else
{
// It's highly unlikely that APPn related data will be found after the SOS marker
// We should have gathered everything we need by now.
return;
}
case JpegConstants.Markers.DHT:
if (metadataOnly)
{
stream.Skip(remaining);
}
else
{
this.ProcessDefineHuffmanTablesMarker(stream, remaining);
}
break;
case JpegConstants.Markers.DQT:
this.ProcessDefineQuantizationTablesMarker(stream, remaining);
break;
case JpegConstants.Markers.DRI:
if (metadataOnly)
{
stream.Skip(remaining);
}
else
{
this.ProcessDefineRestartIntervalMarker(stream, remaining);
}
break;
case JpegConstants.Markers.APP0:
this.ProcessApplicationHeaderMarker(stream, remaining);
break;
case JpegConstants.Markers.APP1:
this.ProcessApp1Marker(stream, remaining);
break;
case JpegConstants.Markers.APP2:
this.ProcessApp2Marker(stream, remaining);
break;
case JpegConstants.Markers.APP3:
case JpegConstants.Markers.APP4:
case JpegConstants.Markers.APP5:
case JpegConstants.Markers.APP6:
case JpegConstants.Markers.APP7:
case JpegConstants.Markers.APP8:
case JpegConstants.Markers.APP9:
case JpegConstants.Markers.APP10:
case JpegConstants.Markers.APP11:
case JpegConstants.Markers.APP12:
stream.Skip(remaining);
break;
case JpegConstants.Markers.APP13:
this.ProcessApp13Marker(stream, remaining);
break;
case JpegConstants.Markers.APP14:
this.ProcessApp14Marker(stream, remaining);
break;
case JpegConstants.Markers.APP15:
case JpegConstants.Markers.COM:
stream.Skip(remaining);
break;
}
}
// Read on.
fileMarker = FindNextFileMarker(this.markerBuffer, stream);
}
}
