1. A method of image processing, comprising: acquiring a current frame and a previous frame; s performing a bilateral motion estimation to the current frame and the previous frame for acquiring a motion vector, wherein the step of performing the bilateral motion estimation further comprises: generating at least one adaptive sum of bilateral absolute difference, wherein the bilateral motion estimation uses a sum of bilateral absolute difference algorithm to generate at least one sum of bilateral absolute difference, and an adaptive parameter is added to each sum of bilateral absolute difference for generating the adaptive sum of bilateral absolute difference; determining one group of best matching blocks by determining the adaptive sum with the smallest value in at least one group of matching blocks from the current frame and the previous frame, and the group of best matching blocks are the group of matching blocks with the smallest adaptive sum value; acquiring the motion vector according to a relative position of the group of the best matching blocks; and performing a motion compensation to the current frame, the previous frame, and the motion vector for acquiring an interpolated frame.