public void ComponentScalingIsCorrect_1ChannelJpegGolang()
{
using (GolangJpegDecoderCore decoder = JpegFixture.ParseGolangStream(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);
GolangComponent c0 = decoder.Components[0];
VerifyJpeg.VerifyComponent(c0, expectedSizeInBlocks, uniform1, uniform1);
}
}
public void PrintComponentDataGolang(string imageFile)
{
var sb = new StringBuilder();
using (GolangJpegDecoderCore decoder = JpegFixture.ParseGolangStream(imageFile))
{
sb.AppendLine(imageFile);
sb.AppendLine($"Size:{decoder.ImageSizeInPixels} MCU:{decoder.ImageSizeInMCU}");
GolangComponent c0 = decoder.Components[0];
GolangComponent c1 = decoder.Components[1];
sb.AppendLine($"Luma: SAMP: {c0.SamplingFactors} BLOCKS: {c0.SizeInBlocks}");
sb.AppendLine($"Chroma: {c1.SamplingFactors} BLOCKS: {c1.SizeInBlocks}");
}
this.Output.WriteLine(sb.ToString());
}
public static ComponentData Load(GolangComponent c)
{
var result = new ComponentData(
c.SizeInBlocks.Width,
c.SizeInBlocks.Height,
c.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_MultiChannelJpegGolang(
string imageFile,
int componentCount,
object expectedLumaFactors,
object expectedChromaFactors)
{
var fLuma = (Size)expectedLumaFactors;
var fChroma = (Size)expectedChromaFactors;
using (GolangJpegDecoderCore decoder = JpegFixture.ParseGolangStream(imageFile))
{
Assert.Equal(componentCount, decoder.ComponentCount);
Assert.Equal(componentCount, decoder.Components.Length);
GolangComponent c0 = decoder.Components[0];
GolangComponent c1 = decoder.Components[1];
GolangComponent 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)
{
GolangComponent c3 = decoder.Components[2];
VerifyJpeg.VerifyComponent(c3, expectedLumaSizeInBlocks, fLuma, uniform1);
}
}
}
/// <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="metadataOnly">Whether to decode metadata only.</param>
private void ProcessStartOfFrameMarker(int remaining, bool metadataOnly)
{
if (this.ComponentCount != 0)
{
throw new ImageFormatException("Multiple SOF markers");
}
switch (remaining)
{
case 6 + (3 * 1): // grayscale image.
this.ComponentCount = 1;
break;
case 6 + (3 * 3): // YCbCr or RGB image.
this.ComponentCount = 3;
break;
case 6 + (3 * 4): // YCbCrK or CMYK image.
this.ComponentCount = 4;
break;
default:
throw new ImageFormatException("Incorrect number of components");
}
this.InputProcessor.ReadFull(this.Temp, 0, remaining);
// We only support 8-bit precision.
if (this.Temp[0] != SupportedPrecision)
{
throw new ImageFormatException("Only 8-Bit precision supported.");
}
int height = (this.Temp[1] << 8) + this.Temp[2];
int width = (this.Temp[3] << 8) + this.Temp[4];
this.ImageSizeInPixels = new Size(width, height);
if (this.Temp[5] != this.ComponentCount)
{
throw new ImageFormatException("SOF has wrong length");
}
if (!metadataOnly)
{
this.Components = new GolangComponent[this.ComponentCount];
for (int i = 0; i < this.ComponentCount; i++)
{
byte componentIdentifier = this.Temp[6 + (3 * i)];
var component = new GolangComponent(componentIdentifier, i);
component.InitializeCoreData(this);
this.Components[i] = component;
}
int h0 = this.Components[0].HorizontalSamplingFactor;
int v0 = this.Components[0].VerticalSamplingFactor;
this.ImageSizeInMCU = this.ImageSizeInPixels.DivideRoundUp(8 * h0, 8 * v0);
this.ColorSpace = this.DeduceJpegColorSpace();
foreach (GolangComponent component in this.Components)
{
component.InitializeDerivedData(this.configuration.MemoryManager, this);
}
}
}
