/// <summary>
/// Processes the SOS (Start of scan marker).
/// </summary>
private void ProcessStartOfScanMarker()
{
int selectorsCount = this.InputStream.ReadByte();
int componentIndex = -1;
for (int i = 0; i < selectorsCount; i++)
{
componentIndex = -1;
int selector = this.InputStream.ReadByte();
for (int j = 0; j < this.Frame.ComponentIds.Length; j++)
{
byte id = this.Frame.ComponentIds[j];
if (selector == id)
{
componentIndex = j;
}
}
if (componentIndex < 0)
{
throw new ImageFormatException("Unknown component selector");
}
ref PdfJsFrameComponent component = ref this.Frame.Components[componentIndex];
int tableSpec = this.InputStream.ReadByte();
component.DCHuffmanTableId = tableSpec >> 4;
component.ACHuffmanTableId = tableSpec & 15;
}
internal void QuantizeAndInverseAllComponents()
{
for (int i = 0; i < this.components.Components.Length; i++)
{
PdfJsFrameComponent frameComponent = this.Frame.Components[i];
PdfJsComponent component = this.components.Components[i];
this.QuantizeAndInverseComponentData(component, frameComponent);
}
}
/// <summary>
/// Processes the Start of Frame marker. Specified in section B.2.2.
/// </summary>
/// <param name="remaining">The remaining bytes in the segment block.</param>
/// <param name="frameMarker">The current frame marker.</param>
private void ProcessStartOfFrameMarker(int remaining, PdfJsFileMarker frameMarker)
{
if (this.Frame != null)
{
throw new ImageFormatException("Multiple SOF markers. Only single frame jpegs supported.");
}
this.InputStream.Read(this.temp, 0, remaining);
this.Frame = new PdfJsFrame
{
Extended = frameMarker.Marker == PdfJsJpegConstants.Markers.SOF1,
Progressive = frameMarker.Marker == PdfJsJpegConstants.Markers.SOF2,
Precision = this.temp[0],
Scanlines = (short)((this.temp[1] << 8) | this.temp[2]),
SamplesPerLine = (short)((this.temp[3] << 8) | this.temp[4]),
ComponentCount = this.temp[5]
};
int maxH = 0;
int maxV = 0;
int index = 6;
// No need to pool this. They max out at 4
this.Frame.ComponentIds = new byte[this.Frame.ComponentCount];
this.Frame.Components = new PdfJsFrameComponent[this.Frame.ComponentCount];
for (int i = 0; i < this.Frame.Components.Length; i++)
{
int h = this.temp[index + 1] >> 4;
int v = this.temp[index + 1] & 15;
if (maxH < h)
{
maxH = h;
}
if (maxV < v)
{
maxV = v;
}
var component = new PdfJsFrameComponent(this.Frame, this.temp[index], h, v, this.temp[index + 2], i);
this.Frame.Components[i] = component;
this.Frame.ComponentIds[i] = component.Id;
index += 3;
}
this.Frame.MaxHorizontalFactor = maxH;
this.Frame.MaxVerticalFactor = maxV;
this.Frame.InitComponents();
}
public void ComponentScalingIsCorrect_1ChannelJpegPdfJs()
{
using (PdfJsJpegDecoderCore decoder = JpegFixture.ParsePdfJsStream(TestImages.Jpeg.Baseline.Jpeg400))
{
Assert.Equal(1, decoder.ComponentCount);
Assert.Equal(1, decoder.Components.Length);
Size expectedSizeInBlocks = decoder.ImageSizeInPixels.DivideRoundUp(8);
Assert.Equal(expectedSizeInBlocks, decoder.ImageSizeInMCU);
var uniform1 = new Size(1, 1);
PdfJsFrameComponent c0 = decoder.Components[0];
VerifyJpeg.VerifyComponent(c0, expectedSizeInBlocks, uniform1, uniform1);
}
}
public void PrintComponentDataPdfJs(string imageFile)
{
var sb = new StringBuilder();
using (PdfJsJpegDecoderCore decoder = JpegFixture.ParsePdfJsStream(imageFile))
{
sb.AppendLine(imageFile);
sb.AppendLine($"Size:{decoder.ImageSizeInPixels} MCU:{decoder.ImageSizeInMCU}");
PdfJsFrameComponent c0 = decoder.Components[0];
PdfJsFrameComponent c1 = decoder.Components[1];
sb.AppendLine($"Luma: SAMP: {c0.SamplingFactors} BLOCKS: {c0.SizeInBlocks}");
sb.AppendLine($"Chroma: {c1.SamplingFactors} BLOCKS: {c1.SizeInBlocks}");
}
this.Output.WriteLine(sb.ToString());
}
public static ComponentData Load(PdfJsFrameComponent c, int index)
{
var result = new ComponentData(
c.WidthInBlocks,
c.HeightInBlocks,
index
);
for (int y = 0; y < result.HeightInBlocks; y++)
{
for (int x = 0; x < result.WidthInBlocks; x++)
{
short[] data = c.GetBlockReference(x, y).ToArray();
result.MakeBlock(data, y, x);
}
}
return(result);
}
public void ComponentScalingIsCorrect_MultiChannelJpegPdfJs(
string imageFile,
int componentCount,
object expectedLumaFactors,
object expectedChromaFactors)
{
var fLuma = (Size)expectedLumaFactors;
var fChroma = (Size)expectedChromaFactors;
using (PdfJsJpegDecoderCore decoder = JpegFixture.ParsePdfJsStream(imageFile))
{
Assert.Equal(componentCount, decoder.ComponentCount);
Assert.Equal(componentCount, decoder.Components.Length);
PdfJsFrameComponent c0 = decoder.Components[0];
PdfJsFrameComponent c1 = decoder.Components[1];
PdfJsFrameComponent c2 = decoder.Components[2];
var uniform1 = new Size(1, 1);
Size expectedLumaSizeInBlocks = decoder.ImageSizeInMCU.MultiplyBy(fLuma);
Size divisor = fLuma.DivideBy(fChroma);
Size expectedChromaSizeInBlocks = expectedLumaSizeInBlocks.DivideRoundUp(divisor);
VerifyJpeg.VerifyComponent(c0, expectedLumaSizeInBlocks, fLuma, uniform1);
VerifyJpeg.VerifyComponent(c1, expectedChromaSizeInBlocks, fChroma, divisor);
VerifyJpeg.VerifyComponent(c2, expectedChromaSizeInBlocks, fChroma, divisor);
if (componentCount == 4)
{
PdfJsFrameComponent c3 = decoder.Components[2];
VerifyJpeg.VerifyComponent(c3, expectedLumaSizeInBlocks, fLuma, uniform1);
}
}
}
/// <summary>
/// Parses the input stream for file markers
/// </summary>
/// <param name="metaData">Contains the metadata for an image</param>
/// <param name="metadataOnly">Whether to decode metadata only.</param>
private void ParseStream(ImageMetaData metaData, bool metadataOnly)
{
// TODO: metadata only logic
// Check for the Start Of Image marker.
var fileMarker = new PdfJsFileMarker(this.ReadUint16(), 0);
if (fileMarker.Marker != PdfJsJpegConstants.Markers.SOI)
{
throw new ImageFormatException("Missing SOI marker.");
}
ushort marker = this.ReadUint16();
fileMarker = new PdfJsFileMarker(marker, (int)this.InputStream.Position - 2);
this.quantizationTables = new PdfJsQuantizationTables();
this.dcHuffmanTables = new PdfJsHuffmanTables();
this.acHuffmanTables = new PdfJsHuffmanTables();
while (fileMarker.Marker != PdfJsJpegConstants.Markers.EOI)
{
// Get the marker length
int remaining = this.ReadUint16() - 2;
switch (fileMarker.Marker)
{
case PdfJsJpegConstants.Markers.APP0:
this.ProcessApplicationHeaderMarker(remaining);
break;
case PdfJsJpegConstants.Markers.APP1:
this.ProcessApp1Marker(remaining, metaData);
break;
case PdfJsJpegConstants.Markers.APP2:
this.ProcessApp2Marker(remaining, metaData);
break;
case PdfJsJpegConstants.Markers.APP3:
case PdfJsJpegConstants.Markers.APP4:
case PdfJsJpegConstants.Markers.APP5:
case PdfJsJpegConstants.Markers.APP6:
case PdfJsJpegConstants.Markers.APP7:
case PdfJsJpegConstants.Markers.APP8:
case PdfJsJpegConstants.Markers.APP9:
case PdfJsJpegConstants.Markers.APP10:
case PdfJsJpegConstants.Markers.APP11:
case PdfJsJpegConstants.Markers.APP12:
case PdfJsJpegConstants.Markers.APP13:
this.InputStream.Skip(remaining);
break;
case PdfJsJpegConstants.Markers.APP14:
this.ProcessApp14Marker(remaining);
break;
case PdfJsJpegConstants.Markers.APP15:
case PdfJsJpegConstants.Markers.COM:
this.InputStream.Skip(remaining);
break;
case PdfJsJpegConstants.Markers.DQT:
this.ProcessDefineQuantizationTablesMarker(remaining);
break;
case PdfJsJpegConstants.Markers.SOF0:
case PdfJsJpegConstants.Markers.SOF1:
case PdfJsJpegConstants.Markers.SOF2:
this.ProcessStartOfFrameMarker(remaining, fileMarker);
break;
case PdfJsJpegConstants.Markers.DHT:
this.ProcessDefineHuffmanTablesMarker(remaining);
break;
case PdfJsJpegConstants.Markers.DRI:
this.ProcessDefineRestartIntervalMarker(remaining);
break;
case PdfJsJpegConstants.Markers.SOS:
this.ProcessStartOfScanMarker();
break;
}
// Read on.
fileMarker = FindNextFileMarker(this.markerBuffer, this.InputStream);
}
this.ImageWidth = this.Frame.SamplesPerLine;
this.ImageHeight = this.Frame.Scanlines;
this.components = new PdfJsComponentBlocks {
Components = new PdfJsComponent[this.Frame.ComponentCount]
};
for (int i = 0; i < this.components.Components.Length; i++)
{
PdfJsFrameComponent frameComponent = this.Frame.Components[i];
var component = new PdfJsComponent
{
Scale = new System.Numerics.Vector2(
frameComponent.HorizontalSamplingFactor / (float)this.Frame.MaxHorizontalFactor,
frameComponent.VerticalSamplingFactor / (float)this.Frame.MaxVerticalFactor),
BlocksPerLine = frameComponent.WidthInBlocks,
BlocksPerColumn = frameComponent.HeightInBlocks
};
// this.QuantizeAndInverseComponentData(ref component, frameComponent);
this.components.Components[i] = component;
}
this.NumberOfComponents = this.components.Components.Length;
}
