Change the alpha value of a BufferedImage?

Question

How do I change the global alpha value of a BufferedImage in Java? (I.E. make every pixel in the image that has a alpha value of 100 have a alpha value of 80)

Answer 1

@Neil Coffey: Thanks, I've been looking for this too; however, Your code didn't work very well for me (white background became black).

I coded something like this and it works perfectly:

public void setAlpha(byte alpha) {       
    alpha %= 0xff; 
    for (int cx=0;cx

Where obj_img is BufferedImage.TYPE_INT_ARGB.

I change alpha with setAlpha((byte)125); alpha range is now 0-255.

Hope someone finds this useful.