[bjornornorn]

Just a small correction: Logarithmic != gamma encoded. Most software use sRGB encoding which is close to a power function (often referred to as a gamma function). Logarithmic encoding is often used for encoding HDR images, but is not what most software use.

[jpap]

When I referred to "logarithmic domain", I'm not talking about a purely log/exp transfer function, but one that is "log like". Perhaps it is more accurate to say "non-linear domain"... but I hope you get the idea. :)

The sRGB transfer function is piecewise linear + exponential but can be closely approximated by a simple exponential with \gamma ~= 2.2 [1]. Either way, the encoding between linear and non-linear is generally referred to as "gamma correction", even when using a transfer function that is not a simple exponential.

[1] https://en.wikipedia.org/wiki/SRGB#The_forward_transformatio...

[mark-r]

sRGB was engineered to be indistinguishable from a power 2.2 function, even though it's harder to calculate.