Imagick
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Imagick::contrastImage

(PECL imagick 2.0.0)

Imagick::contrastImage — Change the contrast of the image

说明

bool Imagick::contrastImage ( bool $sharpen )

Enhances the intensity differences between the lighter and darker elements of the image. Set sharpen to a value other than 0 to increase the image contrast otherwise the contrast is reduced.

参数

sharpen

The sharpen value

返回值

成功时返回 TRUE .

错误/异常

错误时抛出 ImagickException .

Imagick
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PHP手册 - N: Change the contrast of the image

用户评论:

xyking (16-Apr-2010 04:14)

Tip:
<?php
$image->contrastImage(1); //Increase contrast once
$image->contrastImage(1); //Increase contrast more
$image->contrastImage(1); //Increase contrast even more

$image->contrastImage(0); //Decrease contrast once
$image->contrastImage(0); //Decrease contrast more
$image->contrastImage(0); //Decrease contrast even more

//This could be made into a function like this:
public function contrast($level) {
        $level = (int)$level;
        if ($level < -10) {
            $level = -10;
        } else if ($level > 10) {
            $level = 10;
        }
        if ($level > 0) {
            for ($i = 0; $i < $level; $i++) {
                $this->image->contrastImage(1);
            }
        } else if ($level < 0) {
            for ($i = $level; $i > 0; $i--) {
                $this->image->contrastImage(0);
            }
        }
    }
?>

goekar at msn dot com (08-Aug-2007 01:33)

<?
$image = new Imagick('test.jpg'); // open image file
$image->contrastImage(9); // 0 - 9
$image->writeImage('test2.jpg'); //save image
?>