iTextSharp CCITTFAX3 CCITTFAX4

Hi,

Given a fax image embedded in a pdf. I have used the code below to successfully extract an image.

My particular image uses CCITTFAX3 and not CCITTFAX4. Does anyone know what property I can read in the PDF or infer using LibTiff.NET to obtain the correct compression depending on how the image was encoded.

case "/CCITTFaxDecode":

      byte[] data = PdfReader.GetStreamBytesRaw((PRStream)pdfStream);
      int tiff = TIFFOpen("example.tif", "w");
      TIFFSetField(tiff, (uint)BitMiracle.LibTiff.Classic.TiffTag.IMAGEWIDTH,(uint)Int32.Parse(width));
      TIFFSetField(tiff, (uint)BitMiracle.LibTiff.Classic.TiffTag.IMAGEHEIGHT, (uint)Int32.Parse(height));
      TIFFSetField(tiff, (uint)BitMiarcle.LibTiff.Classic.TiffTag.COMPRESSION, (uint)BitMiracle.Libtiff.Classic.Compression.CCITTFAX4);
      TIFFSetField(tiff, (uint)BitMiracle.LibTiff.Classic.TiffTag.BITSPERSAMPLE, (uint)Int32.Parse(bpp));
      TIFFSetField(tiff, (uint)BitMiarcle.Libtiff.Classic.TiffTag.SAMPLESPERPIXEL,1 );

      IntPtr pointer = Marshal.AllocHGlobal(data.length);
      Marshal.copy(data, 0, pointer, data.length);
      TIFFWriteRawStrip(tiff, 0, pointer, data.length);
      TIFFClose(tiff);

      break;

The code above is originally from this question http://stackoverflow.com/questions/2641770/extracting-image-from-pdf-with-ccittfaxdecode-filter

Thanks

ansaurus

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iTextSharp CCITTFAX3 CCITTFAX4

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