x^a*y^a = (xy)^a
Now, for fixed y, and x1 = r, x2 = g, x3 = b
r^ay^a = (ry)^a
g^ay^a = (gy)^a
b^a*y^a = (by^a
hey look, no change in the ratios of g/y/b whether multiplying by y inside of the gamma relationship or by y^a outside
your mind = blown
You keep on ranting about chrominance shifts… Chrominance shifts that I’ve only seen when playing with your tone equalizer.
Undesired luminance changes? Maybe. But, perceptually (as opposed to mathematically) - averaging two values in gamma-space gives a perception closer to a midpoint between those two values than averaging in linear-space prior to converting to gamma. I need to do more digging, but it probebly explains why (despite your insistence that blending in nonlinear space will cause haloing) - blending in linear space causes haloing not seen when blending/exposure fusing in gamma-2.4 space.
Upper is interpolation in linear space. Lower is interpolation in gamma-space (specifically, gamma=2.4) - and yes, I readily admit I’m currently not dealing with the linear transfer at very low values seen in sRGB (where the gamma outside of said linear region is 2.4 but the average is 2.2-2.3)
BTW, where’s the chrominance shift you insist MUST me occurring in such an operation as shown in this image?