(PECL imagick 2.0.0)
Imagick::contrastImage — Change the contrast of the image
$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.
sharpen
The sharpen value
成功时返回 TRUE。
错误时抛出 ImagickException。
xyking (2010-04-16 08:14:25)
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);
}
}
}
?>