public static async Task <int> Wrap(FileInfo source, FileInfo output, CancellationToken cancellationToken)
{
if (source is null || !source.Exists)
{
Console.WriteLine(source is null ? "Input JPEG image is not specified." : "File not found: " + source.FullName);
return(1);
}
if (output is null)
{
Console.WriteLine("Output TIFF file is not specified.");
return(1);
}
byte[] jpegFile = await File.ReadAllBytesAsync(source.FullName, cancellationToken);
var decoder = new JpegDecoder();
decoder.SetInput(jpegFile);
decoder.Identify(loadQuantizationTables: false);
ushort[] bitsPerSample = new ushort[decoder.NumberOfComponents];
ushort bits = (ushort)decoder.Precision;
for (int i = 0; i < bitsPerSample.Length; i++)
{
bitsPerSample[i] = bits;
}
TiffPhotometricInterpretation photometricInterpretation =
bitsPerSample.Length == 1 ? TiffPhotometricInterpretation.BlackIsZero :
bitsPerSample.Length == 3 ? TiffPhotometricInterpretation.YCbCr :
throw new InvalidDataException("Photometric interpretation not supported.");
using (TiffFileWriter writer = await TiffFileWriter.OpenAsync(output.FullName, useBigTiff: false))
{
TiffStreamOffset imageOffset = await writer.WriteAlignedBytesAsync(jpegFile);
TiffStreamOffset ifdOffset;
using (TiffImageFileDirectoryWriter ifdWriter = writer.CreateImageFileDirectory())
{
await ifdWriter.WriteTagAsync(TiffTag.ImageWidth, TiffValueCollection.Single((ushort)decoder.Width));
await ifdWriter.WriteTagAsync(TiffTag.ImageLength, TiffValueCollection.Single((ushort)decoder.Height));
await ifdWriter.WriteTagAsync(TiffTag.BitsPerSample, TiffValueCollection.UnsafeWrap(bitsPerSample));
await ifdWriter.WriteTagAsync(TiffTag.Compression, TiffValueCollection.Single((ushort)TiffCompression.Jpeg));
await ifdWriter.WriteTagAsync(TiffTag.PhotometricInterpretation, TiffValueCollection.Single((ushort)photometricInterpretation));
await ifdWriter.WriteTagAsync(TiffTag.SamplesPerPixel, TiffValueCollection.Single((ushort)bitsPerSample.Length));
await ifdWriter.WriteTagAsync(TiffTag.PlanarConfiguration, TiffValueCollection.Single((ushort)TiffPlanarConfiguration.Chunky));
await ifdWriter.WriteTagAsync(TiffTag.RowsPerStrip, TiffValueCollection.Single((ushort)decoder.Height));
await ifdWriter.WriteTagAsync(TiffTag.StripOffsets, TiffValueCollection.Single((uint)imageOffset.Offset));
await ifdWriter.WriteTagAsync(TiffTag.StripByteCounts, TiffValueCollection.Single((uint)jpegFile.Length));
if (photometricInterpretation == TiffPhotometricInterpretation.YCbCr)
{
int maxHorizontalSampling = decoder.GetMaximumHorizontalSampling();
int maxVerticalSampling = decoder.GetMaximumVerticalSampling();
int yHorizontalSubSampling = maxHorizontalSampling / decoder.GetHorizontalSampling(0);
int yVerticalSubSampling = maxVerticalSampling / decoder.GetVerticalSampling(0);
int cbHorizontalSubSampling = maxHorizontalSampling / decoder.GetHorizontalSampling(1) / yHorizontalSubSampling;
int cbVerticalSubSampling = maxVerticalSampling / decoder.GetVerticalSampling(1) / yVerticalSubSampling;
int crHorizontalSubSampling = maxHorizontalSampling / decoder.GetHorizontalSampling(2) / yHorizontalSubSampling;
int crVerticalSubSampling = maxVerticalSampling / decoder.GetVerticalSampling(2) / yVerticalSubSampling;
if (cbHorizontalSubSampling != crHorizontalSubSampling || cbVerticalSubSampling != crVerticalSubSampling)
{
throw new InvalidDataException("Unsupported JPEG image.");
}
await ifdWriter.WriteTagAsync(TiffTag.YCbCrSubSampling, TiffValueCollection.UnsafeWrap(new ushort[] { (ushort)cbHorizontalSubSampling, (ushort)cbVerticalSubSampling }));
}
// Write other properties here (eg, XResolution, YResolution)
await ifdWriter.WriteTagAsync(TiffTag.XResolution, TiffValueCollection.Single(new TiffRational(96, 1)));
await ifdWriter.WriteTagAsync(TiffTag.YResolution, TiffValueCollection.Single(new TiffRational(96, 1)));
await ifdWriter.WriteTagAsync(TiffTag.ResolutionUnit, TiffValueCollection.Single((ushort)TiffResolutionUnit.Inch));
ifdOffset = await ifdWriter.FlushAsync();
}
writer.SetFirstImageFileDirectoryOffset(ifdOffset);
await writer.FlushAsync();
}
return(0);
}