The Imagick class
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Imagick::contrastStretchImage

(PECL imagick 2.0.0)

Imagick::contrastStretchImageEnhances the contrast of a color image

说明

bool Imagick::contrastStretchImage ( float $black_point , float $white_point [, int $channel=Imagick::CHANNEL_ALL ] )
Warning

本函数暂无文档,仅有参数列表。

Enhances the contrast of a color image by adjusting the pixels color to span the entire range of colors available

参数

black_point

The black point.

white_point

The white point.

channel

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.

返回值

Returns TRUE on success.


The Imagick class
PHP 手册