(I think this has been discussed on the list before, but not sure where/when.)
What is the best way to achieve the following functionality -
Given two layers L1 and L2, I want L2 limited by it's distance from L1
Result <- L1 - MIN( MAX(L1 - L2), -20), 20)
(This expression uses L1/L2 as placeholder for each pixel in all RGB channels)
Options:
A. Write a plugin
B. Write it as a script-fu (not sure if script-fu can iterate on pixels, and what is the speed implication). And I hate scheme.
C. Write it in python fu if I can compile it, but even though it is probably not as universally available as scrip-fu. Can I iterate over an image in python-fu?
D. I know I can do it with 5 layers and overlay modes. write this as a script-fu. Not elegant and requires loads of memory for large images.
Layer Mode
L1 Grain Merge 148 Darken Only 108 Lighten Only L1 Grain Extract L2 Normal
(148/108 stand for a layer filled with gray pixels (148,148,148)/(108,108,108)
E. Write a generic framework which allows any kind of expression(s) between layer(s) (Only kidding ...)
F. Anything better?
-Joseph
