Image cropping in java

Question

Hi All,

I want to cut a particular shape of an image in java, for example an image which contains a man with white background, here I want to crop the man without the background. Don't want to make it as transparent image, want to cut with some coordinates. I think using the cropImageFilter we can only cut the rectangle region. Can anyone tel me how to do this?

Thanks is advance.

Answer 1

First, you need to create a java.awt.image.BufferedImage from a java.awt.Image. Here's some code to do that, from DZone Snippets.

/**
 * @author Anthony Eden
 */
public class BufferedImageBuilder {

    private static final int DEFAULT_IMAGE_TYPE = BufferedImage.TYPE_INT_RGB;

    public BufferedImage bufferImage(Image image) {
        return bufferImage(image, DEFAULT_IMAGE_TYPE);
    }

    public BufferedImage bufferImage(Image image, int type) {
        BufferedImage bufferedImage = new BufferedImage(image.getWidth(null), image.getHeight(null), type);
        Graphics2D g = bufferedImage.createGraphics();
        g.drawImage(image, null, null);
        waitForImage(bufferedImage);
        return bufferedImage;
    }

    private void waitForImage(BufferedImage bufferedImage) {
        final ImageLoadStatus imageLoadStatus = new ImageLoadStatus();
        bufferedImage.getHeight(new ImageObserver() {
            public boolean imageUpdate(Image img, int infoflags, int x, int y, int width, int height) {
                if (infoflags == ALLBITS) {
                    imageLoadStatus.heightDone = true;
                    return true;
                }
                return false;
            }
        });
        bufferedImage.getWidth(new ImageObserver() {
            public boolean imageUpdate(Image img, int infoflags, int x, int y, int width, int height) {
                if (infoflags == ALLBITS) {
                    imageLoadStatus.widthDone = true;
                    return true;
                }
                return false;
            }
        });
        while (!imageLoadStatus.widthDone && !imageLoadStatus.heightDone) {
            try {
                Thread.sleep(300);
            } catch (InterruptedException e) {

            }
        }
    }

    class ImageLoadStatus {

        public boolean widthDone = false;
        public boolean heightDone = false;
    }

}

Now that you have a BufferedImage, you can use that polygon of coordinates you have to turn the pixels that are not the man, transparent. Just use the methods provided in BufferedImage.

You can't literally cut a polygon from a BufferedImage. A BufferedImage has to be a rectangle. The best you can do is make the parts of the image you don't want transparent. Or, you can put the pixels you do want on another rectangular BufferedImage.

Answer 2

I'm not sure but class Graphics2D has amethod clip() that accepts a polygon and I think does what you need.

So create a BufferedImage from your image, and get Graphics2D object with createGraphics()