Imagick::blackThresholdImage

(PECL imagick 2.0.0)

Imagick::blackThresholdImageForces all pixels below the threshold into black

Descrierea

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.

Parametri

threshold

The threshold below which everything turns black

Valorile întoarse

Întoarce TRUE în caz de succes.

Istoria schimbărilor

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

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User Contributed Notes 2 notes

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0
Iddles
2 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.
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0
elmer at web-axis dot net
5 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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