Imagick::whiteThresholdImage

(PECL imagick 2, PECL imagick 3)

Imagick::whiteThresholdImageForce all pixels above the threshold into white

说明

public Imagick::whiteThresholdImage ( mixed $threshold ) : bool

Is like Imagick::ThresholdImage() but force all pixels above the threshold into white while leaving all pixels below the threshold unchanged.

参数

threshold

返回值

成功时返回 true

更新日志

版本 说明
PECL imagick 2.1.0 Now allows a string representing the color as a parameter. Previous versions allow only an ImagickPixel object.

范例

Example #1 Imagick::whiteThresholdImage()

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

?>

User Contributed Notes

elmer at web-axis dot net 30-Nov-2008 03:32
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();
?>