(PECL imagick 2.0.0)
Imagick::evaluateImage — Applies an expression to an image
本函数还未编写文档,仅有参数列表。
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. Refer to this list of channel constants.
Returns TRUE on success.
Throws ImagickException on error.