Apply a gamma correction to a GD image
(PHP 3>= 3.0.13, PHP 4 )
int imagegammacorrect ( resourceimage, floatinputgamma, floatoutputgamma )
The imagegammacorrect() function applies gamma
correction to a gd image stream (image) given
an input gamma, the parameter inputgamma
and an output gamma, the parameter
outputgamma.