On some files libraw_colordata_t::data_maximum is larger than libraw_colordata_t::maximum. Is this considered a bug or a normal situation? Doc says that maximum is a theoretical maximum value for a camera.
LibRaw
raw image decoder
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This is possible and normal
This is possible and normal for some formats. For example, for DNG files color.maximum is read from corresponding tag, that may contain anything.
BTW, could you provide sample file for analysis?
-- Alex Tutubalin @LibRaw LLC
Sure, how to send you the
Sure, how to send you the file (46,9 MB)?
The best way it to share it
The best way it to share it somewhere (Dropbox, google) and send me link.
Or just send via E-mail
my personal e-mail is lexa@lexa.ru
-- Alex Tutubalin @LibRaw LLC
Got the file, thanks.
Got the file, thanks.
This is very special case:
color.maximum is calculated from metadata for these files, this is just 0xfffc - black_level
And after LibRaw::unpack() real data maximum is within this range.
But on postprocessing stage, PhaseOne data are linearized using other metadata contained in file (complex process in phase_one_flat_field() call).
After that stage, real (linearized) data values may have values above color.maximum
-- Alex Tutubalin @LibRaw LLC