Thank you for the help.
I’m being a bit OCD here, but I’d like to be certain that I’m getting the full depth. When I show in 0-1, casual mousing around seems to suggest that it’s scaling from 8-bits to float via value/255.0 division. For example, I can get .5607, .5648, and .5686, but can’t seem to get any intermediate values between those. Those numbers happen to be .0039 apart, and 1/255 happens to equal .0039.
I’ve uploaded an image here:
https://drive.google.com/file/d/0B_YUjY4N7ZJxVDhWS0dGRHF0ek0/view?usp=sharing
if it makes any difference.
(The image is of a Secchi disk in water colored with food coloring. We’re developing a model to map RGB values to absorbance at 440 nm. So I take a picture, then run the water through a spectrophotometer. Of course, still need to adjust for exposure.)
If nothing else, I can look through the code and try to figure out where to just add some printf’s, though I’d rather not do that at this stage. Another solution would be just manually figure out the rectangle coords of the desired region, use dcraw to dump to ASCII PPM, then write a script to average the values in the rectangle. Though, it’d be clunky.