Speaking about file formats. Why is 'bitmap' not supported? I tried it, because often a mask in pure black/white is good enough, and the file size is very low. Very handy if you need a really large mask for sharpness, but don't want it to consume all memory. Another question has already been answered, I think; that a small sized jpg has no effect as it has to be 'unpacked' within TG and eats memory as well.
---Dune