A Variable Search Length Block Matching Algorithm for Motion Estimation

: A new fast search algorithm for block matching motion estimation is presented in this paper. The new algorithm, called the Adaptive Search Length (ASL) algorithm, allows the maximum number of searches for each block of the image to vary according to the difficulty in finding the optimum motion vector. The PSNR of the decoded images produced by a video coder operating with the ASL algorithm were compared with those produced by a coder operating with the full search block matching algorithm. The results presented show that, for a PSNR of within .25 dB of the full search PSNR, the ASL algorithm requires only 10 % of the searches required by the full search algorithm. 1. INTRODUCTION All modern standard video coding algorithms employ motion estimation to reduce the redundancy between successive frames of a video sequence. The method adopted to estimate the motion between frames is the block matching algorithm (BMA) [1]. For the full search BMA, a measure of the difference between ever..