1. A method, suitable for an electronic apparatus comprising a first camera and a motion sensor, the method comprising: providing at least one pre-defined model mask; fetching pose data from the motion sensor, the pose data being related to an orientation or a position of the first camera; adjusting one of the at least one pre-defined model mask into an adaptive model mask according to the pose data; and extracting an object from an image captured by the first camera according to the adaptive model mask.