wouldnt it make more sense adding a feature that allows average/subtract/sum dngs directly? and then develop the resulting dng?
because right now, for example if i want to average 10 dngs, i have to convert 10 dngs to raw, then average them, then develop the resulting file.
the other way would save at least one intermediary step. but of course this also adds a lot of code overhead (but we *could* get rid of the CHDK raw format alltogether in the long term?)