DJ Mike's Tutorials: PHP

ImageMagick Functions

Imagick::blackThresholdImage

Description:

blackThresholdImage ( mixed $threshold )

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

Note: blackThresholdImage does not work the way that the manual says it does. If you enter a non-gray color, you get a colored high contrast image.

Parameters:

threshold

A string or ImagickPixel object representing the threshold color.

Return Values

Returns TRUE on success.

Examples

<?php
header("Content-type: image/jpeg");
$image = new Imagick("opossum.jpg"); 
$image->blackthresholdImage( "#999999" );
echo $image;
?> 

<?php
header("Content-type: image/jpeg");
$image = new Imagick("opossum.jpg"); 
$image->blackthresholdImage( "#3399dd" );
echo $image;
?> 

Created by DJ Mike from Santa Barbara