public Segment(JBIG2StreamDecoder streamDecoder)
{
this.decoder = streamDecoder;
huffmanDecoder = decoder.GetHuffmanDecoder();
arithmeticDecoder = decoder.GetArithmeticDecoder();
mmrDecoder = decoder.GetMMRDecoder();
}
public byte[] DecodeJBIG2(byte[] data, ImageFormat format = ImageFormat.TIFF, int NewWidth = 0, int NewHeight = 0)
{
reader = new Big2StreamReader(data);
ResetDecoder();
bool validFile = CheckHeader();
if (JBIG2StreamDecoder.debug)
{
Console.WriteLine("validFile = " + validFile);
}
if (!validFile)
{
/**
* Assume this is a stream from a PDF so there is no file header,
* end of page segments, or end of file segments. Organisation must
* be sequential, and the number of pages is assumed to be 1.
*/
noOfPagesKnown = true;
randomAccessOrganisation = false;
noOfPages = 1;
/** check to see if there is any global data to be read */
if (globalData != null)
{
/** set the reader to read from the global data */
reader = new Big2StreamReader(globalData);
huffmanDecoder = new HuffmanDecoder(reader);
mmrDecoder = new MMRDecoder(reader);
arithmeticDecoder = new ArithmeticDecoder(reader);
/** read in the global data segments */
ReadSegments();
/** set the reader back to the main data */
reader = new Big2StreamReader(data);
}
else
{
/**
* There's no global data, so move the file pointer back to the
* start of the stream
*/
reader.MovePointer(-8);
}
}
else
{
/**
* We have the file header, so assume it is a valid stand-alone
* file.
*/
if (JBIG2StreamDecoder.debug)
{
Console.WriteLine("==== File Header ====");
}
SetFileHeaderFlags();
if (JBIG2StreamDecoder.debug)
{
Console.WriteLine("randomAccessOrganisation = " + randomAccessOrganisation);
Console.WriteLine("noOfPagesKnown = " + noOfPagesKnown);
}
if (noOfPagesKnown)
{
noOfPages = GetNoOfPages();
if (JBIG2StreamDecoder.debug)
{
Console.WriteLine("noOfPages = " + noOfPages);
}
}
}
huffmanDecoder = new HuffmanDecoder(reader);
mmrDecoder = new MMRDecoder(reader);
arithmeticDecoder = new ArithmeticDecoder(reader);
/** read in the main segment data */
ReadSegments();
//Create Image
var rawimage = FindPageSegement(1).GetPageBitmap();
int width = (int)rawimage.GetWidth();
int height = (int)rawimage.GetHeight();
var dataStream = rawimage.GetData(true);
int stride = (width * 1 + 7) / 8;
// This section is new for .net standard 2.0
var bmp = BitsToImage(dataStream, width, height, stride, format);
if (NewWidth != 0 && NewHeight != 0)
{
var newbitmap = ResizeHelpers.ScaleImage(bmp, NewWidth, NewHeight);
return(newbitmap);
}
return(bmp);
}
