Imagick::contrastStretchImage

(PECL imagick 2.0.0)

Imagick::contrastStretchImage — Enhances the contrast of a color image

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

Enhances the contrast of a color image by adjusting the pixels color to span the entire range of colors available. �˷�����Imagick����ImageMagick 6.2.9���ϰ汾����ʱ���á�

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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. Imagick::CHANNEL_ALL. Refer to this list of channel constants.

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