no_auto_scale is very special use parameter, quote from docs/API-datastruct.html:
Disables pixel values scaling (call to LibRaw::scale_colors()) in LibRaw::dcraw_process().
This is special use value because white balance is performed in scale_colors(), so skipping it will result in non-balanced image.
This setting is targeted to use with no_interpolation, or with own interpolation callback call.
For normal processing you probably need no_auto_bright=1 (and, may be, adjust_maximum_thr=0.0 too)
P.S. www.libraw.org/docs need update w/ actual LibRaw/doc/ contents (forgot to do it on LibRaw 0.20 release)
no_auto_scale is very special use parameter, quote from docs/API-datastruct.html:
Disables pixel values scaling (call to LibRaw::scale_colors()) in LibRaw::dcraw_process().
This is special use value because white balance is performed in scale_colors(), so skipping it will result in non-balanced image.
This setting is targeted to use with no_interpolation, or with own interpolation callback call.
For normal processing you probably need no_auto_bright=1 (and, may be, adjust_maximum_thr=0.0 too)
P.S. www.libraw.org/docs need update w/ actual LibRaw/doc/ contents (forgot to do it on LibRaw 0.20 release)