Imagick::getImageChannelDistortions

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Imagick::getImageChannelDistortions — Gets channel distortions

说明

float Imagick::getImageChannelDistortions ( Imagick $reference , int $metric [, int $channel = Imagick::CHANNEL_DEFAULT ] )

Compares one or more image channels of an image to a reconstructed image and returns the specified distortion metrics 此方法在Imagick基于ImageMagick 6.4.4以上版本编译时可用。

参数

reference: Imagick object containing the reference image
metric: Refer to this list of metric type constants.
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. 缺省为Imagick::CHANNEL_DEFAULT. 参考此通道常数列表

返回值

Returns a double describing the channel distortion.

错误／异常

错误时抛出 ImagickException。