. . . I guess pneumatic tools/scaner sampling/graphic arts & photographic data manipulation technology makes this On Topic for the OTech thread . . .
. . . which would be better for inquiring about the manipulation of this type of data? All the 'pegs are about 150k - 210k and make an interesting slide show documenting the gradual destruction of a PCB with a disk sander attachment/air powered die grinder.
WARNING! If anyone gets the urge to try this at home: eye, lung and finger protection are definitely required/highly recommended (in no particular order, btw!) for the health and safety of biological subsystems held near and dear to all.
What I need to be able to do is to ask for suggestions for an automated a/o drag & drop method of combining bitmap files by addition or subtraction. I used to be able to do this to some extent in X-Res, but it wasn't even close to the same as layering/posterizing big Kodalith transparencies (that'd be the High Contrast Graphic Arts Film that Neanderthalers used to work with on light boxes in the pre-PhotoShop age, to you pixel pushers!)
What I'd really like to be able to do is develop a low budget system for reverse engineering. Using the proper software, a scanner, the afore mentioned implements of destruction and a positioning jig for scanner platen/PCB registration, the traces on a multilayer PCB ought to be easily determined and artwork generated for visual display of the data. Using a spreadsheet or database for parts list and connection listings, a methodology for schematic generation should be fairly easy to develop.
I can visualize doing this using software I already have, but doing it would require a whole lot of coprocessor time (the pattern matching abilities of my brain as opposed to a CPU) and automating the process through batch processing in current software is beyond my experience. I've never really even used photoshop, just some of the alternatives bundled with the vector graphics apps I've needed to buy over the years.
I guess what I'll need is a way to discuss availble filter options to do what amounts to what would now be called the high and low pass digital signal processing that graphics artists used to do optically using photograpihic tools. This was a common practice back in the analog era when automated tools didn't really exist for this type of thing or were unavailable/too expensive for general use.
This whole exercise is actually an interesting twist on the developmental history of graphics arts processes.
p.s. The linked images are extremely high contrast grayscale manipulations of 24 bit jpegs produced to illustrate the process just to get this far into asking for help!