PHP 8.0.0 Beta 4 available for testing


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Imagick::setImageAlphaChannelSets image alpha channel


Imagick::setImageAlphaChannel ( int $mode ) : bool

Activate or deactivate image alpha channel. The mode is one of the Imagick::ALPHACHANNEL_* constants. This method is available if Imagick has been compiled against ImageMagick version 6.3.8 or newer.



One of the Imagick::ALPHACHANNEL_* constants

Return Values

Returns TRUE on success.


Throws ImagickException on error.

See Also

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User Contributed Notes 1 note

simonjjarrett at gmail dot com
5 months 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.

->setImageAlphaChannel(Imagick::ALPHACHANNEL_REMOVE );
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