PHP Manual: Applies a function on the image

Description

public bool Imagick::functionImage ( int $function , array $arguments [, int $channel = Imagick::CHANNEL_DEFAULT ] )

Applies an arithmetic, relational, or logical expression to an image. Use these operators to create lighter or darker versions of an image, to increase or decrease contrast in an image, or to negate the image colors. This method is available if Imagick has been compiled against ImageMagick version 6.4.9 or newer.

Parameters

function: Refer to this list of function constants
arguments: Array of arguments to pass to this function.

Return Values

Returns TRUE on success.

Errors/Exceptions

Throws ImagickException on error.