(PECL imagick 2 >= 2.2.1, PECL imagick 3)
Imagick::getImageChannelRange — Gets channel range
$channel): arrayGets the range for one or more image channels. 此方法在Imagick基于ImageMagick 6.4.0以上版本編譯時(shí)可用。
channel
Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channel constants using bitwise operators. 缺省為Imagick::CHANNEL_DEFAULT.
參考此 通道常數列表
Returns an array containing minima and maxima values of the channel(s).
錯誤時(shí)拋出 ImagickException。