保留BufferedImage.setRGB（）中的alpha值？

Question

I'd like to composite a few images together. Each image has some transparency to it. I'm trying to use BufferedImage for this but there doesn't seem to be any way to use it for this purpose?

We only get the BufferedImage.setRGB() method. Instead I need something where transparent pixels won't overwrite the pixel values below them. How can I go about doing that?

Thanks

Answer 1

/* imageType should be one of the variants that includes alpha  */
final BufferedImage composited = new BufferedImage(width, height, imageType);
final Graphics graphics = composited.getGraphics();
for (final Image layer : layers) {
  /* draw the image at 0,0 */
  graphics.drawImage(layer, 0, 0, null);
}
graphics.dispose();