QT4: which QPainter::CompositionMode is suitable to merge two pixmaps with white background to mix the two foreground contents

Question

I am using QPainter to put a pixmap onto another. The pixmaps have white BG. I want that the result is a pixmap with white BG but with mixed content, even if it is ugly and confused. I want to create a "fusion" image.

Answer 1

It seems that CompositionMode_Darken or CompositionMode_Multiply are suitable for my purpose but I do not know the underlyng maths. I just tried.