Presumably much preprocessing went on before the tutorial actually started. I am hoping for some more information.
1) POSS2 Red and Blue images are ~1.01 "/pixel, the Quick-V images are ~1.7 "/pixel from POSS 1. Is the Quick-V data the source of the green channel, or was it synthesized from the red and blue channels? If the quick-v data, was it resampled to ~1.01 "/pixel or was the red and blue channel data down sampled? If synthesized, how?
2) What is the source of the initial chromatic balance adjustment curves in the tutorial?
3) I am especially curious about the statement "Considering that photographic emulsions have wildly nonlinear responses, a complex transfer curves adjustment is required to achieve the correct chromatic balance. " As far as I can tell from this link:
http://www.astro.caltech.edu/~george/dposs/DPOSS_II.pdf, a large amount of effort went into calibrating the digital data scanned from these plates.
As you might suspect, I am hoping to use POSS2 source data and concentrate on learning PixInsight's huge collection of tools, and how to actually apply them in image processing.
Thanks in advance,
Dan colesworthy
