This class implements a wrapper to turn an InputStream into a RandomAccessIO. To provide random access, the input data from the InputStream is cached in an in-memory buffer. The in-memory buffer size can be limited to a specified size. The data is read into the cache on a as needed basis, blocking only when necessary.

The cache grows automatically as necessary. However, if the data length is known prior to the creation of a ISRandomAccessIO object, it is best to specify that as the initial in-memory buffer size. That will minimize data copying and multiple allocation.

Multi-byte data is read in big-endian order. The in-memory buffer storage is released when 'close()' is called. This class can only be used for data input, not output. The wrapped InputStream is closed when all the input data is cached or when 'close()' is called.

If an out of memory condition is encountered when growing the in-memory buffer an IOException is thrown instead of an OutOfMemoryError. The exception message is "Out of memory to cache input data".

This class is intended for use as a "quick and dirty" way to give network connectivity to RandomAccessIO based classes. It is not intended as an efficient means of implementing network connectivity. Doing such requires reimplementing the RandomAccessIO based classes to directly use network connections.

This class does not use temporary files as buffers, because that would preclude the use in unsigned applets.

Inheritance: RandomAccessIO
コード例 #1
0
ファイル: J2kImage.cs プロジェクト: RavenB/gridsearch
        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;
        }
コード例 #2
0
ファイル: J2kImage.cs プロジェクト: RavenB/gridsearch
        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;
        }