a^b
a raised to the power b.
C programmers should be careful not to misread this notation as
exclusive-or. Note that zero raised to any positive power is zero.
x,y that precisely specify the color,
exept for the brightness information.
output = input ^ gamma
where both input and output are scaled to the range 0 to 1. Within this specification, gamma refers specifically to the function from display output to image samples.