(No version information available, might be only in CVS)
Imagick::evaluateImage — Applies an expression to an image
This function is currently not documented; only its argument list is available.
Applys an arithmetic, relational, or logical expression to an image. Use these operators to lighten or darken an image, to increase or decrease contrast in an image, or to produce the "negative" of an image.
The operator
The value of the operator
Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channeltype constants using bitwise operators. Defaults to Imagick::CHANNEL_ALL. Refer to this list of channel constants.
Returns TRUE on success.
Throws ImagickException on error.