Is it possible to extract raw luminance values from raw image files? Actually, a de-Bayerized flat matrix would be ideal but could (? maybe) deal with a 3 layer RGB matrix -- rather like the output from dcraw, only in PS. Preferably without gamma applied.
What I'd like to do: I'd like to use image stacking for exposure accumulation using "summation" but find that highlights blow out readily. Right now the workaround is to let the highlights go and bring them back with HDR from one (or more) of the original frames, but that's seriously clunky. I'd like a "scaled summation" where a luminance-dependent scaling factor is applied in the sum. I don't yet know how to get there from here in PS (there's a megaclunky way involving dcraw, Matlab, and a stacking program ...), but it seems to me that the first step is to get the luminance info.
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