Searching for a way to do Bitwise XOR on images

Question

I am looking for a way to get the Bitwise XOR of two images on the command line(or in another way that can be implemented in a program or script).

This should result in

Answer 1

Here is how I would do in Java:

Iterate over all the pixels of the two images at once. (for loop (x) inside a for loop (y)). Of course, use a BufferedImage. You can get the color of the pixel by doing:

int color = img.getRGB(x, y);

Do the same for the other image as well and perform the xor operation on the two colors. Store the resulting value in a new BufferedImage with the same dimensions as the two input images.

Here is some sample code:

public static BufferedImage xorEffect(BufferedImage imageA, BufferedImage imageB) {
    if (imageA.getWidth() != imageB.getWidth() ||
        imageA.getHeight() != imageB.getHeight())
    {
        throw new IllegalArgumentException("Dimensions are not the same!");
    }
    BufferedImage img = new BufferedImage(imageA.getWidth(),
                                          imageA.getHeight(),
                                          BufferedImage.TYPE_INT_ARGB_PRE);

    for (int y = 0; y < imageA.getHeight(); ++y) {
        for (int x = 0; x < imageA.getWidth(); ++x) {
           int pixelA = imageA.getRGB(x, y);
           int pixelB = imageB.getRGB(x, y);
           int pixelXOR = pixelA ^ pixelB;
           img.setRGB(x, y, pixelXOR);
        }
    }
    return img;
}

To load an image from a file use:

BufferedImage imageA = ImageIO.read(new File("/home/username/image.png"));