gamma (power-law) transformation

A tunable point operation, f(v) = v^gamma, that lightens or darkens depending on the exponent.

The gamma transformation, $f(v)=v^\gamma$ on normalized $[0,1]$ values, bows the mapping curve upward ( $\gamma<1$ , lightening dark values) or downward ( $\gamma>1$ , darkening them); gamma correction applies $\gamma\approx1/2.2$ to pre-compensate for display nonlinearity.