/** * @param li ImageLevelInfo object * @param con JDBC Connection * @return the resolution for li, based on a random chosen tile * @throws SQLException * @throws IOException */ protected double[] getPixelResolution(ImageLevelInfo li, Connection con) throws SQLException, IOException { double[] result = null; String statementString = getRandomTileStatement(li); PreparedStatement s = con.prepareStatement(statementString); ResultSet r = s.executeQuery(); while (r.next()) { byte[] tileBytes = getTileBytes(r); if (tileBytes == null) { continue; } BufferedImage buffImage = null; li.setCanImageIOReadFromInputStream(true); try { buffImage = ImageIO.read(new ByteArrayInputStream(tileBytes)); } catch (IOException e) { } if (buffImage == null) { if (LOGGER.isLoggable(Level.WARNING)) { LOGGER.warning( "Image IO cannot read from ByteInputStream,use less efficient jai methods"); } li.setCanImageIOReadFromInputStream(false); SeekableStream stream = new ByteArraySeekableStream(tileBytes); String decoderName = null; for (String dn : ImageCodec.getDecoderNames(stream)) { decoderName = dn; break; } ImageDecoder decoder = ImageCodec.createImageDecoder(decoderName, stream, null); PlanarImage img = PlanarImage.wrapRenderedImage(decoder.decodeAsRenderedImage()); buffImage = img.getAsBufferedImage(); } Envelope env = getEnvelopeFromResultSet(r); result = new double[] { env.getWidth() / buffImage.getWidth(), env.getHeight() / buffImage.getHeight() }; break; } r.close(); s.close(); return result; }