()
Imagick::setImageAlphaChannel — Sets image alpha channel
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
Returns TRUE on success.
Lance une exception ImagickException si une erreur survient.