Imagick::gammaImage()

(PECL imagick 2.0.0)

Gamma-corrects an image

说明

Imagick::gammaImage(float $gamma[,int $channel= Imagick::CHANNEL_DEFAULT]): bool

Gamma-corrects an image. The same image viewed on different devices will have perceptual differences in the way the image's intensities are represented on the screen. Specify individual gamma levels for the red, green, and blue channels, or adjust all three with the gamma parameter. Values typically range from 0.8 to 2.3.

参数

$gamma

The amount of gamma-correction.

$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. Refer to this list of channel constants.

返回值

成功时返回TRUE。

错误／异常

错误时抛出 ImagickException。

范例

Example #1 Imagick::gammaImage()

<?php
function gammaImage($imagePath, $gamma, $channel) {
    $imagick = new \Imagick(realpath($imagePath));
    $imagick->gammaImage($gamma, $channel);
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();
}
?>

You should use PECL to install this library. Or if you are using composer like me, you should use this packagist package or the similar packages:
"https://packagist.org/packages/tpmanc/yii2-imagick"