/// <summary>
/// Generated from text on F-23, F.13 - Huffman decoded of AC coefficients
/// on ISO DIS 10918-1. Requirements and Guidelines.
/// </summary>
internal void decode_ac_coefficients(JPEGBinaryReader JPEGStream, float[] zz)
{
for (int k = 1; k < 64; k++)
{
int s = ACTable.Decode(JPEGStream);
int r = s >> 4;
s &= 15;
if (s != 0)
{
k += r;
r = (int)JPEGStream.ReadBits(s);
s = (int)HuffmanTable.Extend(r, s);
zz[k] = s;
}
else
{
if (r != 15)
{
//throw new JPEGMarkerFoundException();
return;
}
k += 15;
}
}
}
public JpegComponent(JpegScan parentScan, byte id, byte factorHorizontal, byte factorVertical,
byte quantizationID, byte colorMode)
{
parent = parentScan;
/* Set default tables in case they're not provided. J. Powers */
// TODO: only gen if needed
if (colorMode == JPEGFrame.JPEG_COLOR_YCbCr)
{
if (id == 1) // Luminance
{
ACTable = new HuffmanTable(JpegHuffmanTable.StdACLuminance);
DCTable = new HuffmanTable(JpegHuffmanTable.StdDCLuminance);
}
else
{
ACTable = new HuffmanTable( JpegHuffmanTable.StdACChrominance);
DCTable = new HuffmanTable( JpegHuffmanTable.StdACLuminance);
}
}
component_id = id;
factorH = factorHorizontal;
factorV = factorVertical;
quant_id = quantizationID;
}
public JpegComponent(JpegScan parentScan, byte id, byte factorHorizontal, byte factorVertical,
byte quantizationID, byte colorMode)
{
parent = parentScan;
/* Set default tables in case they're not provided. J. Powers */
// TODO: only gen if needed
if (colorMode == JPEGFrame.JPEG_COLOR_YCbCr)
{
if (id == 1) // Luminance
{
ACTable = new HuffmanTable(JpegHuffmanTable.StdACLuminance);
DCTable = new HuffmanTable(JpegHuffmanTable.StdDCLuminance);
}
else
{
ACTable = new HuffmanTable(JpegHuffmanTable.StdACChrominance);
DCTable = new HuffmanTable(JpegHuffmanTable.StdACLuminance);
}
}
component_id = id;
factorH = factorHorizontal;
factorV = factorVertical;
quant_id = quantizationID;
}
/// <summary>
/// Generated from text on F-22, F.2.2.1 - Huffman decoding of DC
/// coefficients on ISO DIS 10918-1. Requirements and Guidelines.
/// </summary>
/// <param name="JPEGStream">Stream that contains huffman bits</param>
/// <returns>DC coefficient</returns>
public float decode_dc_coefficient(JPEGBinaryReader JPEGStream)
{
int t = DCTable.Decode(JPEGStream);
float diff = JPEGStream.ReadBits(t);
diff = HuffmanTable.Extend((int)diff, t);
diff = (previousDC + diff);
previousDC = diff;
return(diff);
}
public void DecodeDCFirst(JPEGBinaryReader stream, float[] dest)
{
float[] datablock = new float[64];
int s = DCTable.Decode(stream);
int r = stream.ReadBits(s);
s = HuffmanTable.Extend(r, s);
s = (int)previousDC + s;
previousDC = s;
dest[0] = s << successiveLow;
}
/// <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, int quality, Stream outStream)
{
_input = decodedJpeg;
/* This encoder requires YCbCr */
_input.Image.ChangeColorSpace(ColorSpace.YCbCr);
_quality = quality;
_height = _input.Image.Height;
_width = _input.Image.Width;
_outStream = outStream;
_dct = new DCT(_quality);
_huf = new HuffmanTable(null);
}
public void DecodeACFirst(JPEGBinaryReader stream, float[] zz)
{
if (stream.eob_run > 0)
{
stream.eob_run--;
return;
}
for (int k = spectralStart; k <= spectralEnd; k++)
{
int s = ACTable.Decode(stream);
int r = s >> 4;
s &= 15;
if (s != 0)
{
k += r;
r = (int)stream.ReadBits(s);
s = (int)HuffmanTable.Extend(r, s);
zz[k] = s << successiveLow;
}
else
{
if (r != 15)
{
stream.eob_run = 1 << r;
if (r != 0)
{
stream.eob_run += stream.ReadBits(r);
}
stream.eob_run--;
break;
}
k += 15;
}
}
}
public void setDCTable(JpegHuffmanTable table)
{
DCTable = new HuffmanTable(table);
}
public void setACTable(JpegHuffmanTable table)
{
ACTable = new HuffmanTable(table);
}
