ByteBuffer to BufferedImage over WritableRaster: Image is upside down

Question

Hey all!
I have a native Buffer containing RGB-Values (3 bytes per Pixel). I found a Code-Sample in this Forum which works fine for me:
[http://forums.sun.com/thread.jspa?messageID=10784665#10784665]
The thing is, the BufferedImage is "Upside down". Is there a simple way to tell the Raster (or whatever) in which direction the buffer should be read?
I don't wan't to use image transformation because of the time needed by CPU for the transformation.
Best regards,
Billie

Answer 1

The BufferedImage is stored in a File (JPEG).
The callback-Function is called from JNI and the ByteBuffer contains the RGB value's. This code creates my BufferedImage:
    private ByteBuffer buffer = null;
    private int[] bOffs = { 0, 1, 2 };
    private ColorModel colorModel =
        new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
            new int[] { 8, 8, 8 },
            false,
            false,
            Transparency.TRANSLUCENT,
            DataBuffer.TYPE_BYTE);
     * Called within JNI
     * @param byteBuffer the native memory buffer
     * @param width the image with in pixels
     * @param height the image height in pixels
     * @param bitCount the number of bits per pixel
    protected synchronized void callback(ByteBuffer byteBuffer, int width, int height, int bitCount) {
        String method = "callback(ByteBuffer, int, int, int)";
        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug(method, "byteBuffer="
                + byteBuffer
                + ",width="
                + width
                + ",height="
                + height
                + ",bitCount="
                + bitCount);
        try {
            if (buffer == null) {
                buffer = ByteBuffer.allocate(byteBuffer.capacity());
            buffer.position(0);
            buffer.put(byteBuffer);
            WritableRaster raster =
                Raster.createInterleavedRaster(new DataBufferByte(buffer.array(), buffer.capacity()),
                    width,
                    height,
                    width * 3,
                    3,
                    bOffs,
                    null);
            bfImage = new BufferedImage(colorModel, raster, false, null);
        } catch (Exception e) {
            LOGGER.error(method, "Error createing BufferedImage", e);
        notify();
    }And this code stores the image on disk:
        ImageWriterSpi imageWriterSpi = (ImageWriterSpi) IIORegistry
            .getDefaultInstance()
            .getServiceProviderByClass(Class.forName(properties.getProperty(KEY_IMAGE_SPI))); // com.sun.imageio.plugins.jpeg.JPEGImageWriterSpi
        imageWriter = imageWriterSpi.createWriterInstance();
                    imageWriter.reset();
                    imageWriter.setOutput(ImageIO.createImageOutputStream(new FileOutputStream(new File(
                        directory,
                        fileName + ".jpg"))));
                    imageWriter.write(null, new IIOImage(bufferedImage, null, null), imageWriteParam);The BufferedImage isn't touched between this two parts.