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; wherein the adjusting step comprises at least one of the following: when the pose data indicates that the first camera is moved downward, the pre-defined model mask is adjusted such that a bypassing area of the adaptive model mask is larger in a lower region and narrower in an upper region; when the pose data indicates that the first camera is moved upward, the pre-defined model mask is adjusted such that the bypassing area of the adaptive model mask is larger in the upper region and narrower in the lower region; and when the pose data indicates that the first camera is moved to the right side, the pre-defined model mask is adjusted such that the bypassing area of the adaptive model mask is larger on the right side and narrower on the left side.