This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Create a BufferedImage with the same size. Paint the original image on the BufferedImage. Then, go through all pixels of the BufferedImage using getWidth(), getHeight() and getRGB(), and reset the pixel using setRGB if it's a white pixel.