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    Imagick::getImageAlphaChannel

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

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

    Description

    public Imagick::getImageAlphaChannel(): bool

    Returns whether the image has an alpha channel.

    Parameters

    This function has no parameters.

    Return Values

    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.

    Errors/Exceptions

    Throws ImagickException on error.

    Changelog

    Version Description
    imagick 3.6.0 Returns a bool now; previously, an int 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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