Use Imagick::queryFormats() to get a list of possible format names that might be returned by this function.
(PECL imagick 2.0.0)
Imagick::getImageFormat — Returns the format of a particular image in a sequence
Returns the format of a particular image in a sequence.
Returns a string containing the image format on success.
错误时抛出 ImagickException。
Use Imagick::queryFormats() to get a list of possible format names that might be returned by this function.