This class reads the file format wrapper that may or may not exist around a valid JPEG 2000 codestream. Since no information from the file format is used in the actual decoding, this class simply goes through the file and finds the first valid codestream.
Example #1
0
        public static Image FromStream(Stream stream)
        {
            RandomAccessIO in_stream = new ISRandomAccessIO(stream);

            // Initialize default parameters
            ParameterList defpl = GetDefaultParameterList(decoder_pinfo);

            // Create parameter list using defaults
            ParameterList pl = new ParameterList(defpl);

            // **** File Format ****
            // If the codestream is wrapped in the jp2 fileformat, Read the
            // file format wrapper
            FileFormatReader ff = new FileFormatReader(in_stream);
            ff.readFileFormat();
            if (ff.JP2FFUsed)
            {
                in_stream.seek(ff.FirstCodeStreamPos);
            }

            // +----------------------------+
            // | Instantiate decoding chain |
            // +----------------------------+

            // **** Header decoder ****
            // Instantiate header decoder and read main header 
            HeaderInfo hi = new HeaderInfo();
            HeaderDecoder hd;
            try
            {
                hd = new HeaderDecoder(in_stream, pl, hi);
            }
            catch (EndOfStreamException e)
            {
                throw new ApplicationException("Codestream too short or bad header, unable to decode.", e);
            }

            int nCompCod = hd.NumComps;
            int nTiles = hi.sizValue.NumTiles;
            DecoderSpecs decSpec = hd.DecoderSpecs;

            // Get demixed bitdepths
            int[] depth = new int[nCompCod];
            for (int i = 0; i < nCompCod; i++)
            {
                depth[i] = hd.getOriginalBitDepth(i);
            }

            // **** Bit stream reader ****
            BitstreamReaderAgent breader;
            try
            {
                breader = BitstreamReaderAgent.
                    createInstance(in_stream, hd, pl, decSpec,
                                   false, hi);
            }
            catch (IOException e)
            {
                throw new ApplicationException("Error while reading bit stream header or parsing packets.", e);
            }
            catch (ArgumentException e)
            {
                throw new ApplicationException("Cannot instantiate bit stream reader.", e);
            }

            // **** Entropy decoder ****
            EntropyDecoder entdec;
            try
            {
                entdec = hd.createEntropyDecoder(breader, pl);
            }
            catch (ArgumentException e)
            {
                throw new ApplicationException("Cannot instantiate entropy decoder.", e);
            }

            // **** ROI de-scaler ****
            ROIDeScaler roids;
            try
            {
                roids = hd.createROIDeScaler(entdec, pl, decSpec);
            }
            catch (ArgumentException e)
            {
                throw new ApplicationException("Cannot instantiate roi de-scaler.", e);
            }

            // **** Dequantizer ****
            Dequantizer deq;
            try
            {
                deq = hd.createDequantizer(roids, depth, decSpec);
            }
            catch (ArgumentException e)
            {
                throw new ApplicationException("Cannot instantiate dequantizer.", e);
            }

            // **** Inverse wavelet transform ***
            InverseWT invWT;
            try
            {
                // full page inverse wavelet transform
                invWT = InverseWT.createInstance(deq, decSpec);
            }
            catch (ArgumentException e)
            {
                throw new ApplicationException("Cannot instantiate inverse wavelet transform.", e);
            }

            int res = breader.ImgRes;
            invWT.ImgResLevel = res;

            // **** Data converter **** (after inverse transform module)
            ImgDataConverter converter = new ImgDataConverter(invWT, 0);

            // **** Inverse component transformation **** 
            InvCompTransf ictransf = new InvCompTransf(converter, decSpec, depth, pl);

            // **** Color space mapping ****
            BlkImgDataSrc color;
            if (ff.JP2FFUsed && pl.getParameter("nocolorspace").Equals("off"))
            {
                try
                {
                    ColorSpace csMap = new ColorSpace(in_stream, hd, pl);
                    BlkImgDataSrc channels = hd.createChannelDefinitionMapper(ictransf, csMap);
                    BlkImgDataSrc resampled = hd.createResampler(channels, csMap);
                    BlkImgDataSrc palettized = hd.createPalettizedColorSpaceMapper(resampled, csMap);
                    color = hd.createColorSpaceMapper(palettized, csMap);
                }
                catch (ArgumentException e)
                {
                    throw new ApplicationException("Could not instantiate ICC profiler.", e);
                }
                catch (ColorSpaceException e)
                {
                    throw new ApplicationException("Error processing ColorSpace information.", e);
                }
            }
            else
            { // Skip colorspace mapping
                color = ictransf;
            }

            // This is the last image in the decoding chain and should be
            // assigned by the last transformation:
            BlkImgDataSrc decodedImage = color;
            if (color == null)
            {
                decodedImage = ictransf;
            }
            int numComps = decodedImage.NumComps;

            int bytesPerPixel = (numComps == 4 ? 4 : 3);

            // **** Copy to Bitmap ****
            PixelFormat pixelFormat;
            switch (numComps)
            {
                case 1:
                    pixelFormat = PixelFormat.Format24bppRgb; break;
                case 3:
                    pixelFormat = PixelFormat.Format24bppRgb; break;
                case 4:
                    pixelFormat = PixelFormat.Format32bppArgb; break;
                default:
                    throw new ApplicationException("Unsupported PixelFormat.  " + numComps + " components.");
            }

            Bitmap dst = new Bitmap(decodedImage.ImgWidth, decodedImage.ImgHeight, pixelFormat);

            Coord numTiles = decodedImage.getNumTiles(null);

            int tIdx = 0;

            for (int y = 0; y < numTiles.y; y++)
            {
                // Loop on horizontal tiles
                for (int x = 0; x < numTiles.x; x++, tIdx++)
                {
                    decodedImage.setTile(x, y);

                    int height = decodedImage.getTileCompHeight(tIdx, 0);
                    int width = decodedImage.getTileCompWidth(tIdx, 0);

                    int tOffx = decodedImage.getCompULX(0) -
                        (int)Math.Ceiling(decodedImage.ImgULX /
                           (double)decodedImage.getCompSubsX(0));

                    int tOffy = decodedImage.getCompULY(0) -
                        (int)Math.Ceiling(decodedImage.ImgULY /
                            (double)decodedImage.getCompSubsY(0));

                    DataBlkInt[] db = new DataBlkInt[numComps];
                    int[] ls = new int[numComps];
                    int[] mv = new int[numComps];
                    int[] fb = new int[numComps];
                    for (int i = 0; i < numComps; i++)
                    {
                        db[i] = new DataBlkInt();
                        ls[i] = 1 << (decodedImage.getNomRangeBits(0) - 1);
                        mv[i] = (1 << decodedImage.getNomRangeBits(0)) - 1;
                        fb[i] = decodedImage.getFixedPoint(0);
                    }
                    for (int l = 0; l < height; l++)
                    {
                        for (int i = numComps - 1; i >= 0; i--)
                        {
                            db[i].ulx = 0;
                            db[i].uly = l;
                            db[i].w = width;
                            db[i].h = 1;
                            decodedImage.getInternCompData(db[i], i);
                        }
                        int[] k = new int[numComps];
                        for (int i = numComps - 1; i >= 0; i--) k[i] = db[i].offset + width - 1;

                        byte[] rowvalues = new byte[width * bytesPerPixel];

                        for (int i = width - 1; i >= 0; i--)
                        {
                            int[] tmp = new int[numComps];
                            for (int j = numComps - 1; j >= 0; j--)
                            {
                                tmp[j] = (db[j].data_array[k[j]--] >> fb[j]) + ls[j];
                                tmp[j] = (tmp[j] < 0) ? 0 : ((tmp[j] > mv[j]) ? mv[j] : tmp[j]);

                                if (decodedImage.getNomRangeBits(j) != 8)
                                    tmp[j] = (int)Math.Round(((double)tmp[j] / Math.Pow(2D, (double)decodedImage.getNomRangeBits(j))) * 255D);

                            }
                            int offset = i * bytesPerPixel;
                            switch (numComps)
                            {
                                case 1:
                                    rowvalues[offset + 0] = (byte)tmp[0];
                                    rowvalues[offset + 1] = (byte)tmp[0];
                                    rowvalues[offset + 2] = (byte)tmp[0];
                                    break;
                                case 3:
                                    rowvalues[offset + 0] = (byte)tmp[2];
                                    rowvalues[offset + 1] = (byte)tmp[1];
                                    rowvalues[offset + 2] = (byte)tmp[0];
                                    break;
                                case 4:
                                    rowvalues[offset + 0] = (byte)tmp[3];
                                    rowvalues[offset + 1] = (byte)tmp[2];
                                    rowvalues[offset + 2] = (byte)tmp[1];
                                    rowvalues[offset + 3] = (byte)tmp[0];
                                    break;
                            }
                        }

                        BitmapData dstdata = dst.LockBits(
                            new System.Drawing.Rectangle(tOffx, tOffy + l, width, 1),
                            ImageLockMode.ReadWrite, pixelFormat);

                        IntPtr ptr = dstdata.Scan0;
                        System.Runtime.InteropServices.Marshal.Copy(rowvalues, 0, ptr, rowvalues.Length);
                        dst.UnlockBits(dstdata);
                    }
                }
            }
            return dst;
        }
Example #2
0
        public static List<int> GetLayerBoundaries(Stream stream)
        {
            RandomAccessIO in_stream = new ISRandomAccessIO(stream);

            // Create parameter list using defaults
            ParameterList pl = new ParameterList(GetDefaultParameterList(decoder_pinfo));

            // **** File Format ****
            // If the codestream is wrapped in the jp2 fileformat, Read the
            // file format wrapper
            FileFormatReader ff = new FileFormatReader(in_stream);
            ff.readFileFormat();
            if (ff.JP2FFUsed)
            {
                in_stream.seek(ff.FirstCodeStreamPos);
            }

            // +----------------------------+
            // | Instantiate decoding chain |
            // +----------------------------+

            // **** Header decoder ****
            // Instantiate header decoder and read main header 
            HeaderInfo hi = new HeaderInfo();
            HeaderDecoder hd;
            try
            {
                hd = new HeaderDecoder(in_stream, pl, hi);
            }
            catch (EndOfStreamException e)
            {
                throw new ArgumentException("Codestream too short or bad header, unable to decode.", e);
            }

            int nCompCod = hd.NumComps;
            int nTiles = hi.sizValue.NumTiles;
            DecoderSpecs decSpec = hd.DecoderSpecs;

            // Get demixed bitdepths
            int[] depth = new int[nCompCod];
            for (int i = 0; i < nCompCod; i++)
            {
                depth[i] = hd.getOriginalBitDepth(i);
            }

            // **** Bit stream reader ****
            BitstreamReaderAgent breader;
            try
            {
                breader = BitstreamReaderAgent.createInstance(in_stream, hd, pl, decSpec, false, hi);
            }
            catch (IOException e)
            {
                throw new ArgumentException("Error while reading bit stream header or parsing packets.", e);
            }
            catch (ArgumentException e)
            {
                throw new ArgumentException("Cannot instantiate bit stream reader.", e);
            }

            breader.setTile(0, 0);

            return ((FileBitstreamReaderAgent)breader).layerStarts;
        }