Motion estimation refers to estimating 2D motion vector field of the scene or object according to temporal information redundancy in a clipped video.It plays a key role in the super resolution image restoration technique

which maps pixels of all low resolution observations onto corresponding pixels in the reference frame.So its accuracy is highly required.Block-based motion estimation is widely used in super resolution image restoration.This paper introduces the model of block-based motion estimation

summarizes four categories of fast motion estimation methods

describes in detail the search process of several influential algorithms belonging to the first category

and then compares several fast block-matching algorithms.