public void TestYCbCr8ToRgba32(byte y, byte cb, byte cr)
{
var converter = TiffYCbCrConverter8.CreateDefault();
Span <byte> ycbcr = stackalloc byte[9];
ycbcr[0] = y;
ycbcr[1] = cb;
ycbcr[2] = cr;
ycbcr[3] = y;
ycbcr[4] = cb;
ycbcr[5] = cr;
ycbcr[6] = y;
ycbcr[7] = cb;
ycbcr[8] = cr;
Span <TiffRgba32> rgba = stackalloc TiffRgba32[3];
Span <byte> ycbcrBack = stackalloc byte[9];
converter.ConvertToRgba32(ycbcr, rgba, 3);
for (int i = 0; i < 3; i++)
{
converter.ConvertFromRgb24(new TiffRgb24(rgba[i].R, rgba[i].G, rgba[i].B), out ycbcrBack[i * 3], out ycbcrBack[i * 3 + 1], out ycbcrBack[i * 3 + 2]);
}
Assert.True(ycbcr.SequenceEqual(ycbcrBack));
}
public void TestYCbCr8ToRgb24(byte y, byte cb, byte cr)
{
var converter = TiffYCbCrConverter8.CreateDefault();
TiffRgb24 pixel = converter.ConvertToRgb24(y, cb, cr);
converter.ConvertFromRgb24(pixel, out byte oy, out byte ocb, out byte ocr);
Assert.Equal(y, oy);
Assert.Equal(cb, ocb);
Assert.Equal(cr, ocr);
Span <byte> ycbcr = stackalloc byte[9];
ycbcr[0] = y;
ycbcr[1] = cb;
ycbcr[2] = cr;
ycbcr[3] = y;
ycbcr[4] = cb;
ycbcr[5] = cr;
ycbcr[6] = y;
ycbcr[7] = cb;
ycbcr[8] = cr;
Span <TiffRgb24> rgb = stackalloc TiffRgb24[3];
Span <byte> ycbcrBack = stackalloc byte[9];
converter.ConvertToRgb24(ycbcr, rgb, 3);
converter.ConvertFromRgb24(rgb, ycbcrBack, 3);
Assert.True(ycbcr.SequenceEqual(ycbcrBack));
}
public async ValueTask InvokeAsync(TiffImageEncoderContext <TPixel> context, ITiffImageEncoderPipelineNode <TPixel> next)
{
MemoryPool <byte> memoryPool = context.MemoryPool ?? MemoryPool <byte> .Shared;
TiffSize imageSize = context.ImageSize;
int arraySize = 3 * imageSize.Width * imageSize.Height;
using (IMemoryOwner <byte> pixelData = memoryPool.Rent(arraySize))
{
Memory <byte> pixelDataMemory = pixelData.Memory;
using (var writer = new TiffMemoryPixelBufferWriter <TiffRgb24>(memoryPool, pixelDataMemory, imageSize.Width, imageSize.Height))
using (TiffPixelBufferWriter <TPixel> convertedWriter = context.ConvertWriter(writer.AsPixelBufferWriter()))
{
await context.GetReader().ReadAsync(convertedWriter, context.CancellationToken).ConfigureAwait(false);
}
TiffYCbCrConverter8.CreateDefault().ConvertFromRgb24(MemoryMarshal.Cast <byte, TiffRgb24>(pixelDataMemory.Span), pixelDataMemory.Span, imageSize.Width * imageSize.Height);
context.PhotometricInterpretation = TiffPhotometricInterpretation.YCbCr;
context.BitsPerSample = TiffValueCollection.UnsafeWrap(s_bitsPerSample);
context.UncompressedData = pixelDataMemory.Slice(0, arraySize);
await next.RunAsync(context).ConfigureAwait(false);
context.UncompressedData = default;
}
TiffImageFileDirectoryWriter?ifdWriter = context.IfdWriter;
if (!(ifdWriter is null))
{
using (await context.LockAsync().ConfigureAwait(false))
{
await ifdWriter.WriteTagAsync(TiffTag.PhotometricInterpretation, TiffValueCollection.Single((ushort)context.PhotometricInterpretation)).ConfigureAwait(false);
await ifdWriter.WriteTagAsync(TiffTag.BitsPerSample, context.BitsPerSample).ConfigureAwait(false);
await ifdWriter.WriteTagAsync(TiffTag.SamplesPerPixel, TiffValueCollection.Single <ushort>(3)).ConfigureAwait(false);
await ifdWriter.WriteTagAsync(TiffTag.YCbCrCoefficients, TiffYCbCrConverter8.DefaultLuma).ConfigureAwait(false);
await ifdWriter.WriteTagAsync(TiffTag.ReferenceBlackWhite, TiffYCbCrConverter8.DefaultReferenceBlackWhite).ConfigureAwait(false);
}
}
}
