Imagick::getImageAlphaChannel

(PECL imagick 2 >= 2.3.0, PECL imagick 3)

Imagick::getImageAlphaChannel — Checks if the image has an alpha channel

Beschreibung

public Imagick::getImageAlphaChannel(): bool

Returns whether the image has an alpha channel.

Parameter-Liste

Diese Funktion besitzt keine Parameter.

Rückgabewerte

Returns true if the image has an alpha channel value and false if not, i.e. the image is RGB rather than RGBA or CMYK rather than CMYKA.

Fehler/Exceptions

Wirft ImagickException bei Fehlern.

Changelog

Version	Beschreibung
PECL imagick 3.6.0	Returns a Boolean now; previously, an Integer was returned.

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User Contributed Notes 1 note

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phroggar ¶

2 years ago

You want to check wether an image has an alpha channel? But you have no control which Imagick Version is used?

Background: 

Method available since ImageMagick 6.4.0
Method returns boolean instead of int since 6.9.x

Example:

$image= new Imagick();
$image->readImage($source_file);

$imageHasAlphaChannel = (method_exists($image, 'getImageAlphaChannel') && ($document->getImageAlphaChannel() === \Imagick::ALPHACHANNEL_ACTIVATE || $document->getImageAlphaChannel()  === true));

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