Please, could anyone answer the following questions?
I think that RAW files store RGB exposition (RGB-E) as continuous values, or, at least, much more continuous with respect to the discrete (i.e. integer) values of its TIFF version, is this right?
If so, do you know a software that allows the following procedure:
1) conversion of RGB-E to HSV-E, that is, E values expressed in HSV color space.
2) raising of V-E (i.e., the V channel of HSV-E) values to the power 1/g, where “g” is greek gamma and its value should be of one’s choice.
3) normalization of new V values and re-conversion of HSV-E to RGB-E (the RAW file should return to its original format after this process).
Thank you for your attention,
Andrea
All out-of-camera RAW files
All out-of-camera RAW files are 'integer', not continuous
-- Alex Tutubalin @LibRaw LLC
RAW conversion
Many thanks. From your answer, I understand that a camera applies the “GAMMA” function (with gamma 2.2, I suppose) to the inside-registered exposure values and converts them to integer numbers. No common user of a common digital camera can access the original exposure values in order to apply a different gamma and enhance the number of pixel levels in a low-exposure zone. Is this right? And does it also apply to any user, and any camera?
Nothing was said about gamma
my reply says nothing about gamma
-- Alex Tutubalin @LibRaw LLC
Yes I know: I wrote
Yes I know: I wrote “understand” instead of “guess”, because I was trying to fix the thing in one time, instead of by instalments . Then:
I’ve read that a raw file stores exposition (E) values linearly, and that a GAMMA function can be applied to them during raw conversion in order to increase the range of pixel values in the lower zones of exposition. This last result can be achieved if E values have not yet been rounded to nearest integers, otherwise the GAMMA application adds no information about these zones. As a first step, could you tell whether or not you agree on this point?