/**
* The CodecOptions parameter should have the following fields set: {@link CodecOptions#width
* width} {@link CodecOptions#height height} {@link CodecOptions#channels channels} {@link
* CodecOptions#bitsPerSample bitsPerSample} {@link CodecOptions#interleaved interleaved} {@link
* CodecOptions#littleEndian littleEndian} {@link CodecOptions#signed signed}
*
* @see Codec#compress(byte[], CodecOptions)
*/
@Override
public byte[] compress(final byte[] data, CodecOptions options) throws FormatException {
if (data == null || data.length == 0) return data;
if (options == null) options = CodecOptions.getDefaultOptions();
if (options.bitsPerSample > 8) {
throw new FormatException("> 8 bit data cannot be compressed with JPEG.");
}
final ByteArrayOutputStream out = new ByteArrayOutputStream();
final BufferedImage img =
AWTImageTools.makeImage(
data,
options.width,
options.height,
options.channels,
options.interleaved,
options.bitsPerSample / 8,
false,
options.littleEndian,
options.signed);
try {
ImageIO.write(img, "jpeg", out);
} catch (final IOException e) {
throw new FormatException("Could not write JPEG data", e);
}
return out.toByteArray();
}
/**
* The CodecOptions parameter should have the following fields set: {@link
* CodecOptions#interleaved interleaved} {@link CodecOptions#littleEndian littleEndian}
*
* @see Codec#decompress(RandomAccessInputStream, CodecOptions)
*/
@Override
public byte[] decompress(final RandomAccessInputStream in, CodecOptions options)
throws FormatException, IOException {
BufferedImage b;
final long fp = in.getFilePointer();
try {
try {
while (in.read() != (byte) 0xff || in.read() != (byte) 0xd8) {
/* Read to data. */
}
in.seek(in.getFilePointer() - 2);
} catch (final EOFException e) {
in.seek(fp);
}
b = ImageIO.read(new BufferedInputStream(new DataInputStream(in), 8192));
} catch (final IOException exc) {
// probably a lossless JPEG; delegate to LosslessJPEGCodec
in.seek(fp);
return new LosslessJPEGCodec().decompress(in, options);
}
if (options == null) options = CodecOptions.getDefaultOptions();
final byte[][] buf = AWTImageTools.getPixelBytes(b, options.littleEndian);
// correct for YCbCr encoding, if necessary
if (options.ycbcr && buf.length == 3) {
final int nBytes = buf[0].length / (b.getWidth() * b.getHeight());
final int mask = (int) (Math.pow(2, nBytes * 8) - 1);
for (int i = 0; i < buf[0].length; i += nBytes) {
final int y = DataTools.bytesToInt(buf[0], i, nBytes, options.littleEndian);
int cb = DataTools.bytesToInt(buf[1], i, nBytes, options.littleEndian);
int cr = DataTools.bytesToInt(buf[2], i, nBytes, options.littleEndian);
cb = Math.max(0, cb - 128);
cr = Math.max(0, cr - 128);
final int red = (int) (y + 1.402 * cr) & mask;
final int green = (int) (y - 0.34414 * cb - 0.71414 * cr) & mask;
final int blue = (int) (y + 1.772 * cb) & mask;
DataTools.unpackBytes(red, buf[0], i, nBytes, options.littleEndian);
DataTools.unpackBytes(green, buf[1], i, nBytes, options.littleEndian);
DataTools.unpackBytes(blue, buf[2], i, nBytes, options.littleEndian);
}
}
byte[] rtn = new byte[buf.length * buf[0].length];
if (buf.length == 1) rtn = buf[0];
else {
if (options.interleaved) {
int next = 0;
for (int i = 0; i < buf[0].length; i++) {
for (int j = 0; j < buf.length; j++) {
rtn[next++] = buf[j][i];
}
}
} else {
for (int i = 0; i < buf.length; i++) {
System.arraycopy(buf[i], 0, rtn, i * buf[0].length, buf[i].length);
}
}
}
return rtn;
}
