(PECL imagick 2.0.0)
Imagick::whiteThresholdImage — Force all pixels above the threshold into white
Is like Imagick::ThresholdImage() but force all pixels above the threshold into white while leaving all pixels below the threshold unchanged.
threshold
成功时返回 TRUE。
| 版本 | 说明 |
|---|---|
| 2.1.0 | Now allows a string representing the color as a parameter. Previous versions allow only an ImagickPixel object. |
elmer at web-axis dot net (2008-11-30 15:32:53)
Here's a example of this function:
<?php
$img = new Imagick();
$img->readImage($image_file_name);
$img->whiteThresholdImage('grey');
$img->writeImage($thumb_file_name);
$img->clear();
$img->destroy();
?>