public CCITTFaxDecodeFilter() 
{

}

Constructor.

 public  void decode(InputStream compressedData,
    OutputStream result,
    COSDictionary options,
    int filterIndex) throws IOException 
{
        // log.warn( "Warning: CCITTFaxDecode.decode is not implemented yet,
        // skipping this stream." );
        // Get ImageParams from PDF
        COSBase baseObj = options.getDictionaryObject(new String[] {"DecodeParms","DP"});
        COSDictionary dict = null;
        if( baseObj instanceof COSDictionary )
        {
            dict = (COSDictionary)baseObj;
        }
        else if( baseObj instanceof COSArray )
        {
            COSArray paramArray = (COSArray)baseObj;
            if( filterIndex <  paramArray.size() )
            {
                dict = (COSDictionary)paramArray.getObject( filterIndex );
            }
            else
            {
                throw new IOException( "Error: DecodeParms cannot be null for CCITTFaxDecode" );
            }
        }
        else if( baseObj == null )
        {
            throw new IOException( "Error: DecodeParms cannot be null for CCITTFaxDecode" );
        }
        else
        {
            throw new IOException( "Error: Expected COSArray or COSDictionary and not " 
                    + baseObj.getClass().getName() );
        }
        int width = options.getInt("Width");
        int height = options.getInt("Height");
        int length = options.getInt(COSName.LENGTH);
        int compressionType = dict.getInt("K");
        boolean blackIs1 = dict.getBoolean("BlackIs1", false);
        // HEADER-INFO and starting point of TAG-DICTIONARY
        writeTagHeader(result, length);
        // IMAGE-DATA
        int i = 0;
        //int sum = 0;
        byte[] buffer = new byte[32768];
        int lentoread = length;
        while ((lentoread  > 0) && ((i = compressedData.read(buffer, 0, Math.min(lentoread, 32768))) != -1))
        {
            //sum += i;
            result.write(buffer, 0, i);
            lentoread = lentoread - i;
        }
        // If lentoread is  > 0 then we need to write out some padding to equal the header
        // We'll use what we have in the buffer it's just padding after all
        while (lentoread  > 0)
        {
            result.write(buffer, 0, Math.min(lentoread, 32768));
            lentoread = lentoread - Math.min(lentoread, 32738);
        }
        //System.out.println("Gelesen: " + sum);
        // TAG-COUNT
        writeTagCount(result);
        // WIDTH 0x0100
        writeTagWidth(result, width);
        // HEIGHT 0x0101
        writeTagHeight(result, height);
        // BITSPERSAMPLE 0x0102
        // Always 1 for CCITTFax
        writeTagBitsPerSample(result, 1);
        // COMPRESSION 0x0103
        writeTagCompression(result, compressionType);
        // PHOTOMETRIC 0x0106
        writeTagPhotometric(result, blackIs1);
        // STRIPOFFSET 0x0111
        // HERE ALWAYS 8, because ImageData comes before TAG-DICTIONARY
        writeTagStripOffset(result, 8);
        // ORIENTATION 0x0112
        writeTagOrientation(result, 1);
        // SamplesPerPixel 0x0115
        writeTagSamplesPerPixel(result, 1);
        // RowsPerStrip 0x0116
        writeTagRowsPerStrip(result, height);
        // Stripcount 0x0117
        writeTagStripByteCount(result, length);
        // XRESOLUTION 0x011A
        // HERE: 200 DPI
        writeTagXRes(result, 200, 1);
        // YRESOLITION 0x011B
        // HERE: 200 DPI
        writeTagYRes(result, 200, 1);
        // ResolutionUnit 0x0128
        // HERE: DPI
        writeTagResolutionUnit(result, 2);
        // SOFTWARE 0x0131
        // minimum 4 chars
        writeTagSoftware(result, "pdfbox".getBytes());
        // DATE AND TIME 0x0132
        writeTagDateTime(result, new Date());
        // END OF TAG-DICT
        writeTagTailer(result);
}

{@inheritDoc}

 public  void encode(InputStream rawData,
    OutputStream result,
    COSDictionary options,
    int filterIndex) throws IOException 
{
        System.err.println("Warning: CCITTFaxDecode.encode is not implemented yet, skipping this stream.");
}

{@inheritDoc}

 public  void writeTagCompression(OutputStream result,
    int type) throws IOException 
{
        // TAG-ID 103
        result.write(1);
        result.write(3);
        // TAG-TYPE SHORT=3
        result.write(0);
        result.write(3);
        // TAG-LEGNTH = 1
        result.write(0);
        result.write(0);
        result.write(0);
        result.write(1);
        // TAG-VALUE
        //@todo typ eintragen; hier immer 4
        result.write(0);
        if (type <  0)
        {
            result.write(4);// G4
        }
        else if (type == 0)
        {
            result.write(3);// G3-1D
        }
        else
        {
            result.write(2);// G3-2D
        }
        result.write(0);
        result.write(0);
}

Write the tag compression.