H.264 introduces intra-prediction coding and uses Lagrangian rate-distortion optimization(RDO) technique to decide the best intra-coding mode.Although the intra-prediction greatly improves the intra-coding efficiency

it enormously increases the computational complexity.In order to decrease the computational complexity of the algorithm

a fast algorithm for intra-prediction mode decision based on pixel's directional relativity is presented in this paper.Experimental results show that compared with the original intra-prediction coding scheme

the proposed algorithm reduces the computational complexity of intra-prediction coding dramatically with only trivial loss of PSNR and increment of bite-rate.