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

I don't believe there's a single simple command to do this. A few options:

• copy into another image with an AlphaComposite specified (downside: not converted in place)
• directly manipulate the raster (downside: can lead to unmanaged images)
• use a filter or BufferedImageOp

The first is the simplest to implement, IMO.