Imagick::setImageAlphaChannel

(PECL imagick 2 >= 2.1.0, PECL imagick 3)

Imagick::setImageAlphaChannel — Sets image alpha channel

Descrierea

public Imagick::setImageAlphaChannel ( int $mode ) : bool

Activate or deactivate image alpha channel. The mode is one of the Imagick::ALPHACHANNEL_* constants. Această metodă este disponibilă dacă Imagick a fost compilat cu ImageMagick de versiunea 6.3.8 sau ulterior.

Parametri

mode: One of the Imagick::ALPHACHANNEL_* constants

Valorile întoarse

Întoarce true în caz de succes.

Erori/Excepții

Emite ImagickException în caz de eroare.

A se vedea și

Imagick::setImageMatte() - Sets the image matte channel
Imagick Alpha Channel Constants

add a note

User Contributed Notes 1 note

down

simonjjarrett at gmail dot com ¶

4 years ago


If you're having trouble with white backgrounds turning black when converting PDFs to other formats, you need to use this function with Imagick::ALPHACHANNEL_REMOVE as the parameter (this is not currently on the constants page, but it exists in PHP 7.2) to remove the alpha channel.

<?php
$im->setImageAlphaChannel(Imagick::ALPHACHANNEL_REMOVE );
?>

add a note