PHP Manual: Control the brightness, saturation, and hue

Description

public void Gmagick::modulateimage ( float $brightness , float $saturation , float $hue )

Lets you control the brightness, saturation, and hue of an image. Hue is the percentage of absolute rotation from the current position. For example 50 results in a counter-clockwise rotation of 90 degrees, 150 results in a clockwise rotation of 90 degrees, with 0 and 200 both resulting in a rotation of 180 degrees.

Parameters

brightness: The percent change in brighness (-100 thru +100).
saturation: The percent change in saturation (-100 thru +100)
hue: The percent change in hue (-100 thru +100)

Return Values

The Gmagick object on success

Errors/Exceptions

Throws an GmagickException on error.