International PHP Conference 2015

Imagick::blackThresholdImage

(PECL imagick 2.0.0)

Imagick::blackThresholdImageForces all pixels below the threshold into black

Beschreibung

bool Imagick::blackThresholdImage ( mixed $threshold )

Is like Imagick::thresholdImage() but forces all pixels below the threshold into black while leaving all pixels above the threshold unchanged.

Parameter-Liste

threshold

The threshold below which everything turns black

R├╝ckgabewerte

Liefert TRUE bei Erfolg.

Changelog

Version Beschreibung
2.1.0 Now allows a string representing the color as a parameter. Previous versions allow only an ImagickPixel object.

Beispiele

Beispiel #1 Imagick::blackThresholdImage()

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

?>

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User Contributed Notes 2 notes

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0
Iddles
4 years ago
You need to pass this function a colour:

<?php

$img
->blackThresholdImage( "#FFFFFF" );

?>

E.g. this blackens any pixel which isn't pure white.
up
0
elmer at web-axis dot net
6 years ago
Here's a example of this function:

<?php
  $img
= new Imagick();
 
$img->readImage($image_file_name);
 
$img->blackThresholdImage('grey');
 
$img->writeImage($thumb_file_name);
 
$img->clear();
 
$img->destroy();
?>
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