how i can rotate image by array of byte in java?

Question

I have array of byte for image , and I want to rotate image by this array , this is my code :

BufferedImage img = ImageUtil.load(inputImagePath);
WritableRaster raster = img .getRaster();
DataBufferByte data   = (DataBufferByte) raster.getDataBuffer();

byte [] pixel = data.getData();

how i can do this ? , thanks

Why do you need to rotate the byte array? Could you use [This](http://stackoverflow.com/questions/15927014/rotating-an-image-90-degrees-in-java)? — J Atkin, May 06 '15 at 20:54
@JAtkin , my goal to create a new algorithm for rotating image by using just array , How to get pixels locations at least ? — safana, May 07 '15 at 11:27
If you want to _create_ a new algorithm, then what exactly are asking? Us to create it for you? If you want to _implement_ some algorithm, then try to do it and if you encounter a problems then ask more specific question. — Nikolay K, May 07 '15 at 15:53
Also working with pixels via byte array is ineffective, see [this](http://stackoverflow.com/a/9470843/4182275) answer for more information. — Nikolay K, May 07 '15 at 16:04
@NikolayKondratyev my problems was I haven't any reference to pixels , but now I have by using this : int w = img.getWidth(null); int h = img.getHeight(null); int[] rgbs = new int[w*h]; img.getRGB(0, 0, w, h, rgbs, 0, w); _ and I create my own algorithm for rotation and flipping image - thanks for your comment — safana, May 07 '15 at 21:01

score 2 · Accepted Answer · answered May 07 '15 at 18:16

After some work, I came up with this:

public class ImageRotation {
    public static void main(String[] args) throws IOException {

        BufferedImage img = ImageIO.read(
                ImageRotation.class
                        .getResourceAsStream("Capture.PNG"));

        JPanel pane = new JPanel();
        pane.setLayout(new BorderLayout());
        pane.add(
                new JLabel("Original", new ImageIcon(img), JLabel.CENTER),
                BorderLayout.WEST);

        pane.add(
                new JLabel("Rotated", new ImageIcon(rotateClockwise(img)), JLabel.CENTER),
                BorderLayout.EAST);

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(pane);
        frame.setVisible(true);
        frame.pack();
    }

    static BufferedImage rotateClockwise(BufferedImage img) {
        int[] origPix = getIntBuff(img);

        int newWidth = img.getHeight();
        int newHeight = img.getWidth();
        int[] buff = new int[newWidth * newHeight];

        // formula for determining pixel mapping
        // (sizeOf(old y) - 1) - old y -> new x
        // old x -> new y

        for (int x = 0; x < img.getWidth(); x++)
            for (int y = 0; y < img.getHeight(); y++) {

                int pix = origPix[x + (y * img.getWidth())];
                int newX = img.getHeight() - 1 - y, newY = x;

                buff[newX + (newWidth * newY)] = pix;
            }
        // we have now rotated the array clockwise, time to place the buffer in an image


        int type = BufferedImage.TYPE_INT_ARGB;
        BufferedImage ret = new BufferedImage(newWidth, newHeight, type);
        WritableRaster wr = ret.getRaster();
        wr.setDataElements(0, 0, newWidth, newHeight, buff);
        return ret;
    }

    // variation of convertTo2DWithoutUsingGetRGB http://stackoverflow.com/a/9470843/4683264
    private static int[] getIntBuff(BufferedImage image) {

        final byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
        final int width = image.getWidth();
        final int height = image.getHeight();
        final boolean hasAlphaChannel = image.getAlphaRaster() != null;

        int[] result = new int[height * width];

        final int pixelLength = hasAlphaChannel ? 4 : 3;
        for (int pixel = 0, resInd = 0; pixel < pixels.length; pixel += pixelLength) {
            int argb = 0;
            if (hasAlphaChannel)
                argb += (((int) pixels[pixel] & 0xff) << 24); // alpha
            else
                argb += -16777216; // 255 alpha

            argb += ((int) pixels[pixel + 1] & 0xff); // blue
            argb += (((int) pixels[pixel + 2] & 0xff) << 8); // green
            argb += (((int) pixels[pixel + 3] & 0xff) << 16); // red
            result[resInd++] = argb;
        }

        return result;
    }

}

Result:

enter image description here

Right now it only rotates the image clockwise, but once you find the pixel mappings from the old to new image for, say, counterclockwise, all you need to change is in the nested for loop in the rotateClockwise method to:

int newX = y, newY = img.getWidth() - 1 - x;

thanks for you , I didn't use your code , but I use this array for rotate image and flipping it and it worked good : int w = img.getWidth(null); int h = img.getHeight(null); int[] rgbs = new int[w*h]; img.getRGB(0, 0, w, h, rgbs, 0, w); — safana, May 07 '15 at 20:52
@safana If this answer helped you, please select as "best answer" — J Atkin, May 08 '15 at 12:47
The little check mark under the vote count on this post. http://stackoverflow.com/help/accepted-answer — J Atkin, May 08 '15 at 14:29

how i can rotate image by array of byte in java?

1 Answers1