1. A motion estimation method comprising: (a) calculating respective mean difference values for a current search point of a search block and neighboring search points within the search block; (b) performing motion estimation around the current search point if the mean difference value of the current search point is smaller than the mean difference values of the neighboring search points; and (c) performing motion estimation based on the mean difference values of at least some of the neighboring search points if the mean difference value of the current search point is not smaller than the mean difference values of at least one the neighboring search points.