Warning: This function is
currently not documented; only the argument list is
available.
Warning: 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.
Returns the interpolation method for the sepcified image.
Return Values
Returns the interpolate method on success, throws ImagickException on
error.