Change a Specific Color in an ImageIcon

Question

I am working with 24x24 pixel icons. And I would like to be able to change a specific color within this icon to a different color. For example turn the white areas to red.

Answer 1

You can do this with a BufferedImage. Take a look at the Java Image I/O documentation.

Answer 2

I don't know of an API method that does that. And by default, Images are not writable. However, if you have a BufferedImage, you could do it like this:

public void changeColor(BufferedImage img, Color old, Color new) {
    final int oldRGB = old.getRGB();
    final int newRGB = new.getRGB();
    for (int x = 0; x < img.getWidth(); x++) {
        for (int y = 0; y < img.getHeight(); y++) {
            if (img.getRGB(x, y) == oldRGB)
                img.setRGB(x, y, newRGB);
        }
    }
}

This is not the most efficient way to do it (it's possible to fetch RGB data into an array instead of one pixel at a time), but for 24x24 images it shouldn't be a problem.