A study of fast block matching algorithms for H.263

Fast block matching algorithms (BMA) have been simulated and tested for the H.263 codec as an alternative to the more computationally expensive full search algorithm (FSA). Comparison of FSA against three step search (TSS), modified motion estimation algorithm (MMEA), and independent orthogonal search (IOSA), have been done when coding with or without the four options of H.263 and results show that these methods offer a good compromise between bit-rate and encoding speed for very low bit-rate (VLB) video coding. A new method utilizing the temporal correlation of motion vectors (MV) has also been developed and simulated. The new method is promising, and its performance is better than nondependent algorithms by subjective assessment.