I’m learning to use GIMP. I see I could add layer mask, but I don’t see the option to add a Level, Curve, etc layer mask, is there a way to do this (like in PS)? (the effect is to have an adjustment layer)
What I could do so far, is to make a duplicate of a base layer, and adjust level/curve in it. but this makes the file grow very big - each additional layer is a copy of the original.
… or you could try with the PhotoFlow GIMP plug-in, which allows to apply a sequence of non-destructive adjustments on a give GIMP layer, and store the result as a new layer.
Here for example I show how to apply adjustments to a GIMP layer in Lab colorspace…