private void applyParameters(CompressionParameters parameters)
{
Debug.Assert(parameters is object);
ClassicCompressor.SmoothingFactor = parameters.SmoothingFactor;
ClassicCompressor.JpegSetQuality(parameters.Quality, true);
if (parameters.SimpleProgressive)
{
ClassicCompressor.JpegSimpleProgression();
}
}
#pragma warning disable IDE1006 // Naming Styles
private void applyParameters(CompressionParameters parameters)
#pragma warning restore IDE1006 // Naming Styles
{
Debug.Assert(parameters is object);
ClassicCompressor.SmoothingFactor = parameters.SmoothingFactor;
ClassicCompressor.JpegSetQuality(parameters.Quality, true);
if (parameters.SimpleProgressive)
{
ClassicCompressor.JpegSimpleProgression();
}
}
/// <summary>
/// Compresses any image described as ICompressSource to JPEG
/// </summary>
/// <param name="source">Contains description of input image</param>
/// <param name="output">Stream for output of compressed JPEG</param>
public void Compress(IRawImage source, Stream output)
{
if (source is null)
{
throw new ArgumentNullException(nameof(source));
}
if (output is null)
{
throw new ArgumentNullException(nameof(output));
}
ClassicCompressor.Image_width = source.Width;
ClassicCompressor.Image_height = source.Height;
ClassicCompressor.In_color_space = (JColorSpace)source.Colorspace;
ClassicCompressor.Input_components = source.ComponentsPerPixel;
//m_compressor.Data_precision = source.DataPrecision;
ClassicCompressor.JpegSetDefaults();
//we need to set density parameters after setting of default jpeg parameters
//m_compressor.Density_unit = source.DensityUnit;
//m_compressor.X_density = (short)source.DensityX;
//m_compressor.Y_density = (short)source.DensityY;
applyParameters(m_compressionParameters);
// Specify data destination for compression
ClassicCompressor.JpegStdioDest(output);
// Start compression
ClassicCompressor.JpegStartCompression(true);
// Process pixels
source.BeginRead();
while (ClassicCompressor.Next_scanline < ClassicCompressor.Image_height)
{
var row = source.GetPixelRow();
var rowForDecompressor = new byte[1][];
rowForDecompressor[0] = row ?? throw new InvalidDataException("Row of pixels is null");
ClassicCompressor.JpegWriteScanlines(rowForDecompressor, 1);
}
source.EndRead();
// Finish compression and release memory
ClassicCompressor.JpegFinishCompress();
}
