The present invention provides an image processing method, wherein the method includes the steps of: receiving an image signal including a first frame and a second frame; determining edges of a foreground in the first frame and the second frame according to at least one motion vector of the first frame and the second frame; determining an edge of the foreground in an interpolated frame according to the edge of the foreground in the first frame and the edge of the foreground in the second frame; and directly using one or more motion vectors of a background adjacent to the foreground in the first frame or the second frame to serve as one or more motion vectors of an outer region of the edge of the foreground in the interpolated frame.