Exposure Fusion and Intel Neo drivers

[anon41087856]

@Entropy512

x^a*y^a = (xy)^a

Now, for fixed y, and x1 = r, x2 = g, x3 = b
r^a y^a = (ry)^a
g^a y^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

Yeah. Now try f(x)^a * f(y)^a where f is a general transfer function defined implicitely by interpolation of nodes. What is it equal to ?

@Entropy512

You keep on ranting about chrominance shifts… Chrominance shifts that I’ve only seen when playing with your tone equalizer.

Or maybe I have more experience than you do on these matters and I know how to make these things break. You are one year too late for this conversation. Chrominance shifts can’t happen in my code, because it’s a simple exposure compensation, so I wonder what you have seen.

@Entropy512

blending in linear space causes haloing not seen when blending/exposure fusing in gamma-2.4 space.

You are annoying.

darktable-org/darktable/blob/a195abd59a3a935946d1432c4ecdf4b0472c78c0/src/iop/basecurve.c#L875-L904

is called before

darktable-org/darktable/blob/a195abd59a3a935946d1432c4ecdf4b0472c78c0/src/iop/basecurve.c#L1076-L1089

where the gaussian pyramid blending and exposures blending happens. So, the blending is not done over pure log, or pure gamma or linearly encoded data, but on whatever goes outside of the tone curve, which is usually an S-shaped curve with raised midtones.