Hi, I need to batch process some pngs, and I'm struggling to simply put them one over another, and blend the alpha channels. Whatever I do, I end up with an image which does NOT preserve alpha values; for instance if a pixel is transparent in both images, it won't be transparent in the output. Of course, I need it to be still transparent.
Obviously I'm missing something.
Which is the way to simply put two png images one over another, and keep transparency?
Sorry to bother with such a basic question, but I didn't find the answer in the alphablending tutorial (where the result is fully opaque)...