Programming Web Graphics with Perl and GNU Softwar

Name

Modulate( ) — adjust the brightness, saturation, and hue

Synopsis

$image->Modulate(brightness=>percentage,
                    saturation=>percentage,
                    hue=>percentage)

Modulate( ) lets you control the brightness, saturation, and hue of an image. Each parameter is in the form of a percentage of the current value for that parameter. For example, to decrease brightness by 10% and increase saturation by 50%, use:

$image->Modulate(brightness=>-10, saturation=>50);