public JpegFrameContext(byte quality, ushort height, ushort width,
JpegQuantizationTable luminance = null, JpegQuantizationTable chrominance = null, byte[] hSampFactor = null, byte[] vSampFactor = null)
{
Quality = quality;
Height = height;
Width = width;
HSampFactor = hSampFactor ?? FrameDefaults.HSampFactor;
VSampFactor = vSampFactor ?? FrameDefaults.VSampFactor;
Luminance = luminance ?? JpegQuantizationTable.K1Luminance;
Chrominance = chrominance ?? JpegQuantizationTable.K2Chrominance;
DCT = new DCT(Quality, Luminance, Chrominance);
HuffmanTable = HuffmanTable.GetHuffmanTable(null);
JpegFrame = new JpegFrame();
JpegFrame.ScanLines = height;
JpegFrame.SamplesPerLine = width;
JpegFrame.Precision = 8; // Number of bits per sample
JpegFrame.ComponentCount = FrameDefaults.NumberOfComponents; // Number of components (Y, Cb, Cr)
var qTables = new JpegQuantizationTable[2];
qTables[0] = JpegQuantizationTable.GetJpegQuantizationTable(DCT.quantum[0]);
qTables[1] = JpegQuantizationTable.GetJpegQuantizationTable(DCT.quantum[1]);
for (byte i = 0; i < FrameDefaults.NumberOfComponents; i++)
{
JpegFrame.AddComponent(FrameDefaults.CompId[i], HSampFactor[i], VSampFactor[i], qTables[FrameDefaults.QtableNumber[i]]);
JpegFrame.SetHuffmanTables(FrameDefaults.CompId[i], JpegFrame.AcTables[FrameDefaults.ACtableNumber[i]], JpegFrame.DcTables[FrameDefaults.DCtableNumber[i]]);
}
}
/// <summary>
/// Encodes a JPEG, preserving the colorspace and metadata of the input JPEG.
/// </summary>
/// <param name="decodedJpeg">Decoded Jpeg to start with.</param>
/// <param name="quality">Quality of the image from 0 to 100. (Compression from max to min.)</param>
/// <param name="outStream">Stream where the result will be placed.</param>
public JpegEncoder(DecodedJpeg decodedJpeg, short quality, Stream outStream)
{
input = decodedJpeg;
/* This encoder requires YCbCr */
input.Image.ChangeColorSpace(ColorSpace.YCbCr);
this.quality = quality;
height = input.Image.Height;
width = input.Image.Width;
this.outStream = outStream;
dct = new DCT(quality);
huf = HuffmanTable.GetHuffmanTable(null);
}