This function is currently not documented; only the argument list is available.
This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function at your own risk.
Implements direct to memory image formats. It returns the image sequence as a string. The format of the image determines the format of the returned blob (GIF, JPEG, PNG, etc.). To return a different image format, use Imagick::SetImageFormat().