'gimp-levels' procedure with GEGL activated.
If I pull the high(right) slider down to, say, 150 the layer gets
extremely white, burned white.
If I deactivate the 'Use GEGL' the layer doesn't get that white, more
close to what I would expect by looking at the histogram.
I noticed something similar with levels, with 2.8. At least on my
computer (opensuse, 2.8 compiled from source) there are three places
where "gegl" can be activated in 2.8: "View, Use Gegl", "Colors, Use
Gegl", and also "Tools, Gegl Operation".
If I use levels to raise the black point of an image (use the lower
left slider rather than the upper right slider) from 0 to 25 (ten
percent of 255), the shadows should be brighter than they used to be,
the midtones affected less, and the highlights hardly at all.
Levels with nothing checked or with "View, Use Gegl" checked (and
"Colors, Use Gegl" not checked) acts as expected.
"Tools, Gegl Operation, levels" using 0.10 (ten percent of 1 rather
than ten percent of 255) also acts as expected, producing the same
effect as above.
But Levels with "Colors, Use Gegl" checked affects the midtones more
than the shadows. The difference is noticeable with an sRGB image,
drastic with a linear gamma image.
Elle
