private void handleSegmentNumber(SegmentHeader segmentHeader)
        {
            short[] segmentbytes = new short[4];
            reader.readbyte(segmentbytes);

            int segmentNumber = BinaryOperation.getInt32(segmentbytes);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("SegmentNumber = " + segmentNumber);
            }
            segmentHeader.setSegmentNumber(segmentNumber);
        }
        private void handleSegmentDataLength(SegmentHeader segmentHeader)
        {
            short[] buf = new short[4];
            reader.readbyte(buf);

            int dateLength = BinaryOperation.getInt32(buf);

            segmentHeader.setDataLength(dateLength);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("dateLength = " + dateLength);
            }
        }
        private void handleReferedToSegmentNumbers(SegmentHeader segmentHeader)
        {
            int referredToSegmentCount = segmentHeader.getReferredToSegmentCount();

            int[] referredToSegments = new int[referredToSegmentCount];

            int segmentNumber = segmentHeader.getSegmentNumber();

            if (segmentNumber <= 256)
            {
                for (int i = 0; i < referredToSegmentCount; i++)
                {
                    referredToSegments[i] = reader.readbyte();
                }
            }
            else if (segmentNumber <= 65536)
            {
                short[] buf = new short[2];
                for (int i = 0; i < referredToSegmentCount; i++)
                {
                    reader.readbyte(buf);
                    referredToSegments[i] = BinaryOperation.getInt16(buf);
                }
            }
            else
            {
                short[] buf = new short[4];
                for (int i = 0; i < referredToSegmentCount; i++)
                {
                    reader.readbyte(buf);
                    referredToSegments[i] = BinaryOperation.getInt32(buf);
                }
            }

            segmentHeader.setReferredToSegments(referredToSegments);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("referredToSegments = ");
                for (int i = 0; i < referredToSegments.Length; i++)
                {
                    Console.WriteLine(referredToSegments[i] + " ");
                }
                Console.WriteLine("");
            }
        }
Пример #4
0
        public override void readSegment()
        {
            short[] buff = new short[4];
            decoder.readbyte(buff);
            regionBitmapWidth = BinaryOperation.getInt32(buff);

            buff = new short[4];
            decoder.readbyte(buff);
            regionBitmapHeight = BinaryOperation.getInt32(buff);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("Bitmap size = " + regionBitmapWidth + 'x' + regionBitmapHeight);
            }

            buff = new short[4];
            decoder.readbyte(buff);
            regionBitmapXLocation = BinaryOperation.getInt32(buff);

            buff = new short[4];
            decoder.readbyte(buff);
            regionBitmapYLocation = BinaryOperation.getInt32(buff);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("Bitmap location = " + regionBitmapXLocation + ',' + regionBitmapYLocation);
            }

            /** extract region Segment flags */
            short regionFlagsField = decoder.readbyte();

            regionFlags.setFlags(regionFlagsField);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("region Segment flags = " + regionFlagsField);
            }
        }
        private void handlePageAssociation(SegmentHeader segmentHeader)
        {
            int pageAssociation;

            bool isPageAssociationSizeSet = segmentHeader.isPageAssociationSizeSet();

            if (isPageAssociationSizeSet)
            { // field is 4 bytes long
                short[] buf = new short[4];
                reader.readbyte(buf);
                pageAssociation = BinaryOperation.getInt32(buf);
            }
            else
            { // field is 1 byte long
                pageAssociation = reader.readbyte();
            }

            segmentHeader.setPageAssociation(pageAssociation);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("pageAssociation = " + pageAssociation);
            }
        }
        public override void readSegment()
        {
            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("==== Reading Text Region ====");
            }

            base.readSegment();

            /** read text region Segment flags */
            readTextRegionFlags();

            short[] buff = new short[4];
            decoder.readbyte(buff);
            long noOfSymbolInstances = BinaryOperation.getInt32(buff);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("noOfSymbolInstances = " + noOfSymbolInstances);
            }

            int noOfReferredToSegments = segmentHeader.getReferredToSegmentCount();

            int[] referredToSegments = segmentHeader.getReferredToSegments();

            //List codeTables = new ArrayList();
            List <Segment> segmentsReferenced = new List <Segment>();
            long           noOfSymbols        = 0;

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("noOfReferredToSegments = " + noOfReferredToSegments);
            }
            int i = 0;

            for (i = 0; i < noOfReferredToSegments; i++)
            {
                Segment seg  = decoder.findSegment(referredToSegments[i]);
                int     type = seg.getSegmentHeader().getSegmentType();

                if (type == Segment.SYMBOL_DICTIONARY)
                {
                    segmentsReferenced.Add(seg);
                    noOfSymbols += ((SymbolDictionarySegment)seg).getNoOfExportedSymbols();
                }
                else if (type == Segment.TABLES)
                {
                    //codeTables.add(seg);
                }
            }

            long symbolCodeLength = 0;
            int  count            = 1;

            while (count < noOfSymbols)
            {
                symbolCodeLength++;
                count <<= 1;
            }

            int currentSymbol = 0;

            JBIG2Bitmap[] symbols = new JBIG2Bitmap[noOfSymbols];
            foreach (Segment it in segmentsReferenced)
            {
                if (it.getSegmentHeader().getSegmentType() == Segment.SYMBOL_DICTIONARY)
                {
                    JBIG2Bitmap[] bitmaps = ((SymbolDictionarySegment)it).getBitmaps();
                    for (int j = 0; j < bitmaps.Length; j++)
                    {
                        symbols[currentSymbol] = bitmaps[j];
                        currentSymbol++;
                    }
                }
            }

            long[,] huffmanFSTable = null;
            long[,] huffmanDSTable = null;
            long[,] huffmanDTTable = null;

            long[,] huffmanRDWTable = null;
            long[,] huffmanRDHTable = null;

            long[,] huffmanRDXTable   = null;
            long[,] huffmanRDYTable   = null;
            long[,] huffmanRSizeTable = null;

            bool sbHuffman = textRegionFlags.getFlagValue(TextRegionFlags.SB_HUFF) != 0;

            i = 0;
            if (sbHuffman)
            {
                int sbHuffFS = textRegionHuffmanFlags.getFlagValue(TextRegionHuffmanFlags.SB_HUFF_FS);
                if (sbHuffFS == 0)
                {
                    huffmanFSTable = HuffmanDecoder.huffmanTableF;
                }
                else if (sbHuffFS == 1)
                {
                    huffmanFSTable = HuffmanDecoder.huffmanTableG;
                }
                else
                {
                }

                int sbHuffDS = textRegionHuffmanFlags.getFlagValue(TextRegionHuffmanFlags.SB_HUFF_DS);
                if (sbHuffDS == 0)
                {
                    huffmanDSTable = HuffmanDecoder.huffmanTableH;
                }
                else if (sbHuffDS == 1)
                {
                    huffmanDSTable = HuffmanDecoder.huffmanTableI;
                }
                else if (sbHuffDS == 2)
                {
                    huffmanDSTable = HuffmanDecoder.huffmanTableJ;
                }
                else
                {
                }

                int sbHuffDT = textRegionHuffmanFlags.getFlagValue(TextRegionHuffmanFlags.SB_HUFF_DT);
                if (sbHuffDT == 0)
                {
                    huffmanDTTable = HuffmanDecoder.huffmanTableK;
                }
                else if (sbHuffDT == 1)
                {
                    huffmanDTTable = HuffmanDecoder.huffmanTableL;
                }
                else if (sbHuffDT == 2)
                {
                    huffmanDTTable = HuffmanDecoder.huffmanTableM;
                }
                else
                {
                }

                int sbHuffRDW = textRegionHuffmanFlags.getFlagValue(TextRegionHuffmanFlags.SB_HUFF_RDW);
                if (sbHuffRDW == 0)
                {
                    huffmanRDWTable = HuffmanDecoder.huffmanTableN;
                }
                else if (sbHuffRDW == 1)
                {
                    huffmanRDWTable = HuffmanDecoder.huffmanTableO;
                }
                else
                {
                }

                int sbHuffRDH = textRegionHuffmanFlags.getFlagValue(TextRegionHuffmanFlags.SB_HUFF_RDH);
                if (sbHuffRDH == 0)
                {
                    huffmanRDHTable = HuffmanDecoder.huffmanTableN;
                }
                else if (sbHuffRDH == 1)
                {
                    huffmanRDHTable = HuffmanDecoder.huffmanTableO;
                }
                else
                {
                }

                int sbHuffRDX = textRegionHuffmanFlags.getFlagValue(TextRegionHuffmanFlags.SB_HUFF_RDX);
                if (sbHuffRDX == 0)
                {
                    huffmanRDXTable = HuffmanDecoder.huffmanTableN;
                }
                else if (sbHuffRDX == 1)
                {
                    huffmanRDXTable = HuffmanDecoder.huffmanTableO;
                }
                else
                {
                }

                int sbHuffRDY = textRegionHuffmanFlags.getFlagValue(TextRegionHuffmanFlags.SB_HUFF_RDY);
                if (sbHuffRDY == 0)
                {
                    huffmanRDYTable = HuffmanDecoder.huffmanTableN;
                }
                else if (sbHuffRDY == 1)
                {
                    huffmanRDYTable = HuffmanDecoder.huffmanTableO;
                }
                else
                {
                }

                int sbHuffRSize = textRegionHuffmanFlags.getFlagValue(TextRegionHuffmanFlags.SB_HUFF_RSIZE);
                if (sbHuffRSize == 0)
                {
                    huffmanRSizeTable = HuffmanDecoder.huffmanTableA;
                }
                else
                {
                }
            }

            long[][] runLengthTable  = new long[36][];
            long[][] symbolCodeTable = new long[noOfSymbols + 1][];
            if (sbHuffman)
            {
                decoder.consumeRemainingBits();

                for (i = 0; i < 32; i++)
                {
                    runLengthTable[i] = new long[] { i, decoder.readBits(4), 0, 0 };
                }

                runLengthTable[32] = new long[] { 0x103, decoder.readBits(4), 2, 0 };

                runLengthTable[33] = new long[] { 0x203, decoder.readBits(4), 3, 0 };

                runLengthTable[34] = new long[] { 0x20b, decoder.readBits(4), 7, 0 };

                runLengthTable[35] = new long[] { 0, 0, HuffmanDecoder.jbig2HuffmanEOT };

                runLengthTable = HuffmanDecoder.buildTable(runLengthTable, 35);

                for (i = 0; i < noOfSymbols; i++)
                {
                    symbolCodeTable[i] = new long[] { i, 0, 0, 0 };
                }

                i = 0;
                while (i < noOfSymbols)
                {
                    long j = huffmanDecoder.decodeInt(runLengthTable).intResult();
                    if (j > 0x200)
                    {
                        for (j -= 0x200; j != 0 && i < noOfSymbols; j--)
                        {
                            symbolCodeTable[i++][1] = 0;
                        }
                    }
                    else if (j > 0x100)
                    {
                        for (j -= 0x100; j != 0 && i < noOfSymbols; j--)
                        {
                            symbolCodeTable[i][1] = symbolCodeTable[i - 1][1];
                            i++;
                        }
                    }
                    else
                    {
                        symbolCodeTable[i++][1] = j;
                    }
                }

                symbolCodeTable[noOfSymbols][1] = 0;
                symbolCodeTable[noOfSymbols][2] = HuffmanDecoder.jbig2HuffmanEOT;
                symbolCodeTable = HuffmanDecoder.buildTable(symbolCodeTable, (int)noOfSymbols);

                decoder.consumeRemainingBits();
            }
            else
            {
                symbolCodeTable = null;
                arithmeticDecoder.resetIntStats((int)symbolCodeLength);
                arithmeticDecoder.start();
            }

            bool symbolRefine        = textRegionFlags.getFlagValue(TextRegionFlags.SB_REFINE) != 0;
            long logStrips           = textRegionFlags.getFlagValue(TextRegionFlags.LOG_SB_STRIPES);
            int  defaultPixel        = textRegionFlags.getFlagValue(TextRegionFlags.SB_DEF_PIXEL);
            int  combinationOperator = textRegionFlags.getFlagValue(TextRegionFlags.SB_COMB_OP);
            bool transposed          = textRegionFlags.getFlagValue(TextRegionFlags.TRANSPOSED) != 0;
            int  referenceCorner     = textRegionFlags.getFlagValue(TextRegionFlags.REF_CORNER);
            int  sOffset             = textRegionFlags.getFlagValue(TextRegionFlags.SB_DS_OFFSET);
            int  template            = textRegionFlags.getFlagValue(TextRegionFlags.SB_R_TEMPLATE);

            if (symbolRefine)
            {
                arithmeticDecoder.resetRefinementStats(template, null);
            }

            JBIG2Bitmap bitmap = new JBIG2Bitmap(regionBitmapWidth, regionBitmapHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder);

            bitmap.readTextRegion2(sbHuffman, symbolRefine, noOfSymbolInstances, logStrips, noOfSymbols, symbolCodeTable, symbolCodeLength, symbols, defaultPixel, combinationOperator, transposed, referenceCorner, sOffset, huffmanFSTable, huffmanDSTable, huffmanDTTable, huffmanRDWTable, huffmanRDHTable, huffmanRDXTable, huffmanRDYTable, huffmanRSizeTable, template, symbolRegionAdaptiveTemplateX, symbolRegionAdaptiveTemplateY, decoder);

            if (inlineImage)
            {
                PageInformationSegment pageSegment = decoder.findPageSegement(segmentHeader.getPageAssociation());
                JBIG2Bitmap            pageBitmap  = pageSegment.getPageBitmap();

                if (JBIG2StreamDecoder.debug)
                {
                    Console.WriteLine(pageBitmap + " " + bitmap);
                }

                int externalCombinationOperator = regionFlags.getFlagValue(RegionFlags.EXTERNAL_COMBINATION_OPERATOR);
                pageBitmap.combine(bitmap, regionBitmapXLocation, regionBitmapYLocation, externalCombinationOperator);
            }
            else
            {
                bitmap.setBitmapNumber(getSegmentHeader().getSegmentNumber());
                decoder.appendBitmap(bitmap);
            }

            decoder.consumeRemainingBits();
        }
        private void readSymbolDictionaryFlags()
        {
            /** extract symbol dictionary flags */
            short[] symbolDictionaryFlagsField = new short[2];
            decoder.readbyte(symbolDictionaryFlagsField);

            int flags = BinaryOperation.getInt16(symbolDictionaryFlagsField);

            symbolDictionaryFlags.setFlags(flags);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("symbolDictionaryFlags = " + flags);
            }

            // symbol dictionary AT flags
            int sdHuff     = symbolDictionaryFlags.getFlagValue(SymbolDictionaryFlags.SD_HUFF);
            int sdTemplate = symbolDictionaryFlags.getFlagValue(SymbolDictionaryFlags.SD_TEMPLATE);

            if (sdHuff == 0)
            {
                if (sdTemplate == 0)
                {
                    symbolDictionaryAdaptiveTemplateX[0] = readATValue();
                    symbolDictionaryAdaptiveTemplateY[0] = readATValue();
                    symbolDictionaryAdaptiveTemplateX[1] = readATValue();
                    symbolDictionaryAdaptiveTemplateY[1] = readATValue();
                    symbolDictionaryAdaptiveTemplateX[2] = readATValue();
                    symbolDictionaryAdaptiveTemplateY[2] = readATValue();
                    symbolDictionaryAdaptiveTemplateX[3] = readATValue();
                    symbolDictionaryAdaptiveTemplateY[3] = readATValue();
                }
                else
                {
                    symbolDictionaryAdaptiveTemplateX[0] = readATValue();
                    symbolDictionaryAdaptiveTemplateY[0] = readATValue();
                }
            }

            // symbol dictionary refinement AT flags
            int refAgg      = symbolDictionaryFlags.getFlagValue(SymbolDictionaryFlags.SD_REF_AGG);
            int sdrTemplate = symbolDictionaryFlags.getFlagValue(SymbolDictionaryFlags.SD_R_TEMPLATE);

            if (refAgg != 0 && sdrTemplate == 0)
            {
                symbolDictionaryRAdaptiveTemplateX[0] = readATValue();
                symbolDictionaryRAdaptiveTemplateY[0] = readATValue();
                symbolDictionaryRAdaptiveTemplateX[1] = readATValue();
                symbolDictionaryRAdaptiveTemplateY[1] = readATValue();
            }

            /** extract no of exported symbols */
            short[] noOfExportedSymbolsField = new short[4];
            decoder.readbyte(noOfExportedSymbolsField);

            int noOfExportedSymbols = BinaryOperation.getInt32(noOfExportedSymbolsField);

            this.noOfExportedSymbols = noOfExportedSymbols;

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("noOfExportedSymbols = " + noOfExportedSymbols);
            }

            /** extract no of new symbols */
            short[] noOfNewSymbolsField = new short[4];
            decoder.readbyte(noOfNewSymbolsField);

            int noOfNewSymbols = BinaryOperation.getInt32(noOfNewSymbolsField);

            this.noOfNewSymbols = noOfNewSymbols;

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("noOfNewSymbols = " + noOfNewSymbols);
            }
        }
Пример #8
0
        public override void readSegment()
        {
            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("==== Reading Page Information Dictionary ====");
            }

            short[] buff = new short[4];
            decoder.readbyte(buff);
            pageBitmapWidth = BinaryOperation.getInt32(buff);

            buff = new short[4];
            decoder.readbyte(buff);
            pageBitmapHeight = BinaryOperation.getInt32(buff);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("Bitmap size = " + pageBitmapWidth + 'x' + pageBitmapHeight);
            }

            buff = new short[4];
            decoder.readbyte(buff);
            xResolution = BinaryOperation.getInt32(buff);

            buff = new short[4];
            decoder.readbyte(buff);
            yResolution = BinaryOperation.getInt32(buff);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("Resolution = " + xResolution + 'x' + yResolution);
            }

            /** extract page information flags */
            short pageInformationFlagsField = decoder.readbyte();

            pageInformationFlags.setFlags(pageInformationFlagsField);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("symbolDictionaryFlags = " + pageInformationFlagsField);
            }

            buff = new short[2];
            decoder.readbyte(buff);
            pageStriping = BinaryOperation.getInt16(buff);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("Page Striping = " + pageStriping);
            }

            int defPix = pageInformationFlags.getFlagValue(PageInformationFlags.DEFAULT_PIXEL_VALUE);

            int height;

            if (pageBitmapHeight == -1)
            {
                height = pageStriping & 0x7fff;
            }
            else
            {
                height = pageBitmapHeight;
            }

            pageBitmap = new JBIG2Bitmap(pageBitmapWidth, height, arithmeticDecoder, huffmanDecoder, mmrDecoder);
            pageBitmap.clear(defPix);
        }
        public override void readSegment()
        {
            /** read text region Segment flags */
            readPatternDictionaryFlags();

            width  = decoder.readbyte();
            height = decoder.readbyte();

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("pattern dictionary size = " + width + " , " + height);
            }

            short[] buf = new short[4];
            decoder.readbyte(buf);
            grayMax = BinaryOperation.getInt32(buf);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("grey max = " + grayMax);
            }

            bool useMMR   = patternDictionaryFlags.getFlagValue(PatternDictionaryFlags.HD_MMR) == 1;
            int  template = patternDictionaryFlags.getFlagValue(PatternDictionaryFlags.HD_TEMPLATE);

            if (!useMMR)
            {
                arithmeticDecoder.resetGenericStats(template, null);
                arithmeticDecoder.start();
            }

            short[] genericBAdaptiveTemplateX = new short[4], genericBAdaptiveTemplateY = new short[4];

            genericBAdaptiveTemplateX[0] = (short)-width;
            genericBAdaptiveTemplateY[0] = 0;
            genericBAdaptiveTemplateX[1] = -3;
            genericBAdaptiveTemplateY[1] = -1;
            genericBAdaptiveTemplateX[2] = 2;
            genericBAdaptiveTemplateY[2] = -2;
            genericBAdaptiveTemplateX[3] = -2;
            genericBAdaptiveTemplateY[3] = -2;

            size = grayMax + 1;

            JBIG2Bitmap bitmap = new JBIG2Bitmap(size * width, height, arithmeticDecoder, huffmanDecoder, mmrDecoder);

            bitmap.clear(0);
            bitmap.readBitmap(useMMR, template, false, false, null, genericBAdaptiveTemplateX, genericBAdaptiveTemplateY, segmentHeader.getSegmentDataLength() - 7);

            JBIG2Bitmap[] bitmaps = new JBIG2Bitmap[size];

            int x = 0;

            for (int i = 0; i < size; i++)
            {
                bitmaps[i] = bitmap.getSlice(x, 0, width, height);
                x         += width;
            }

            this.bitmaps = bitmaps;
        }
 private int getNoOfPages()
 {
     short[] noOfPages = new short[4];
     reader.readbyte(noOfPages);
     return(BinaryOperation.getInt32(noOfPages));
 }
        private void handleSegmentReferredToCountAndRententionFlags(SegmentHeader segmentHeader)
        {
            short referedToSegmentCountAndRetentionFlags = reader.readbyte();

            int referredToSegmentCount = (referedToSegmentCountAndRetentionFlags & 224) >> 5; // 224

            // =
            // 11100000
            short[] retentionFlags = null;
            /** take off the first three bits of the first byte */
            short firstbyte = (short)(referedToSegmentCountAndRetentionFlags & 31); // 31 =

            // 00011111

            if (referredToSegmentCount <= 4)
            { // short form
                retentionFlags    = new short[1];
                retentionFlags[0] = firstbyte;
            }
            else if (referredToSegmentCount == 7)
            { // long form
                short[] longFormCountAndFlags = new short[4];
                /** add the first byte of the four */
                longFormCountAndFlags[0] = firstbyte;

                for (int i = 1; i < 4; i++)
                {
                    // add the next 3 bytes to the array
                    longFormCountAndFlags[i] = reader.readbyte();
                }

                /** get the count of the referred to Segments */
                referredToSegmentCount = BinaryOperation.getInt32(longFormCountAndFlags);

                /** calculate the number of bytes in this field */
                int noOfbytesInField = (int)Math.Ceiling(4 + ((referredToSegmentCount + 1) / 8d));
                // System.out.println("noOfbytesInField = " + noOfbytesInField);

                int noOfRententionFlagbytes = noOfbytesInField - 4;
                retentionFlags = new short[noOfRententionFlagbytes];
                reader.readbyte(retentionFlags);
            }
            else
            { // error
              //throw new JBIG2Exception("Error, 3 bit Segment count field = " + referredToSegmentCount);
            }

            segmentHeader.setReferredToSegmentCount(referredToSegmentCount);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("referredToSegmentCount = " + referredToSegmentCount);
            }

            segmentHeader.setRententionFlags(retentionFlags);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("retentionFlags = ");
            }

            if (JBIG2StreamDecoder.debug)
            {
                for (int i = 0; i < retentionFlags.Length; i++)
                {
                    Console.WriteLine(retentionFlags[i] + " ");
                }
                Console.WriteLine("");
            }
        }
        public override void readSegment()
        {
            readSegment();

            /** read text region Segment flags */
            readHalftoneRegionFlags();

            short[] buf = new short[4];
            decoder.readbyte(buf);
            int gridWidth = BinaryOperation.getInt32(buf);

            buf = new short[4];
            decoder.readbyte(buf);
            int gridHeight = BinaryOperation.getInt32(buf);

            buf = new short[4];
            decoder.readbyte(buf);
            int gridX = BinaryOperation.getInt32(buf);

            buf = new short[4];
            decoder.readbyte(buf);
            int gridY = BinaryOperation.getInt32(buf);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("grid pos and size = " + gridX + ',' + gridY + ' ' + gridWidth + ',' + gridHeight);
            }

            buf = new short[2];
            decoder.readbyte(buf);
            int stepX = BinaryOperation.getInt16(buf);

            buf = new short[2];
            decoder.readbyte(buf);
            int stepY = BinaryOperation.getInt16(buf);

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("step size = " + stepX + ',' + stepY);
            }

            int[] referedToSegments = segmentHeader.getReferredToSegments();
            if (referedToSegments.Length != 1)
            {
                Console.WriteLine("Error in halftone Segment. refSegs should == 1");
            }

            Segment segment = decoder.findSegment(referedToSegments[0]);

            if (segment.getSegmentHeader().getSegmentType() != Segment.PATTERN_DICTIONARY)
            {
                if (JBIG2StreamDecoder.debug)
                {
                    Console.WriteLine("Error in halftone Segment. bad symbol dictionary reference");
                }
            }

            PatternDictionarySegment patternDictionarySegment = (PatternDictionarySegment)segment;

            int bitsPerValue = 0, i = 1;

            while (i < patternDictionarySegment.getSize())
            {
                bitsPerValue++;
                i <<= 1;
            }

            JBIG2Bitmap bitmap        = patternDictionarySegment.getBitmaps()[0];
            long        patternWidth  = bitmap.getWidth();
            long        patternHeight = bitmap.getHeight();

            if (JBIG2StreamDecoder.debug)
            {
                Console.WriteLine("pattern size = " + patternWidth + ',' + patternHeight);
            }

            bool useMMR   = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_MMR) != 0;
            int  template = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_TEMPLATE);

            if (!useMMR)
            {
                arithmeticDecoder.resetGenericStats(template, null);
                arithmeticDecoder.start();
            }

            int halftoneDefaultPixel = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_DEF_PIXEL);

            bitmap = new JBIG2Bitmap(regionBitmapWidth, regionBitmapHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder);
            bitmap.clear(halftoneDefaultPixel);

            bool enableSkip = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_ENABLE_SKIP) != 0;

            JBIG2Bitmap skipBitmap = null;

            if (enableSkip)
            {
                skipBitmap = new JBIG2Bitmap(gridWidth, gridHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder);
                skipBitmap.clear(0);
                for (int y = 0; y < gridHeight; y++)
                {
                    for (int x = 0; x < gridWidth; x++)
                    {
                        int xx = gridX + y * stepY + x * stepX;
                        int yy = gridY + y * stepX - x * stepY;

                        if (((xx + patternWidth) >> 8) <= 0 || (xx >> 8) >= regionBitmapWidth || ((yy + patternHeight) >> 8) <= 0 || (yy >> 8) >= regionBitmapHeight)
                        {
                            skipBitmap.setPixel(y, x, 1);
                        }
                    }
                }
            }

            int[] grayScaleImage = new int[gridWidth * gridHeight];

            short[] genericBAdaptiveTemplateX = new short[4], genericBAdaptiveTemplateY = new short[4];

            genericBAdaptiveTemplateX[0] = (short)(template <= 1 ? 3 : 2);
            genericBAdaptiveTemplateY[0] = -1;
            genericBAdaptiveTemplateX[1] = -3;
            genericBAdaptiveTemplateY[1] = -1;
            genericBAdaptiveTemplateX[2] = 2;
            genericBAdaptiveTemplateY[2] = -2;
            genericBAdaptiveTemplateX[3] = -2;
            genericBAdaptiveTemplateY[3] = -2;

            JBIG2Bitmap grayBitmap;

            for (int j = bitsPerValue - 1; j >= 0; --j)
            {
                grayBitmap = new JBIG2Bitmap(gridWidth, gridHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder);

                grayBitmap.readBitmap(useMMR, template, false, enableSkip, skipBitmap, genericBAdaptiveTemplateX, genericBAdaptiveTemplateY, -1);

                i = 0;
                for (int row = 0; row < gridHeight; row++)
                {
                    for (int col = 0; col < gridWidth; col++)
                    {
                        int bit = grayBitmap.getPixel(col, row) ^ grayScaleImage[i] & 1;
                        grayScaleImage[i] = (grayScaleImage[i] << 1) | bit;
                        i++;
                    }
                }
            }

            int combinationOperator = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_COMB_OP);

            i = 0;
            for (int col = 0; col < gridHeight; col++)
            {
                int xx = gridX + col * stepY;
                int yy = gridY + col * stepX;
                for (int row = 0; row < gridWidth; row++)
                {
                    if (!(enableSkip && skipBitmap.getPixel(col, row) == 1))
                    {
                        JBIG2Bitmap patternBitmap = patternDictionarySegment.getBitmaps()[grayScaleImage[i]];
                        bitmap.combine(patternBitmap, xx >> 8, yy >> 8, combinationOperator);
                    }

                    xx += stepX;
                    yy -= stepY;

                    i++;
                }
            }

            if (inlineImage)
            {
                PageInformationSegment pageSegment = decoder.findPageSegement(segmentHeader.getPageAssociation());
                JBIG2Bitmap            pageBitmap  = pageSegment.getPageBitmap();

                int externalCombinationOperator = regionFlags.getFlagValue(RegionFlags.EXTERNAL_COMBINATION_OPERATOR);
                pageBitmap.combine(bitmap, regionBitmapXLocation, regionBitmapYLocation, externalCombinationOperator);
            }
            else
            {
                bitmap.setBitmapNumber(getSegmentHeader().getSegmentNumber());
                decoder.appendBitmap(bitmap);
            }
        }