Novel block-matching algorithms by subsampling both search candidates and pixels

A new faster block-matching algorithm (BMA) by using both search candidate and pixel subsamplings is proposed. Firstly a pixel-subsampling approach used in adjustable partial distortion search (APDS) is adjusted to visit about half points of all search candidates by subsampling them, using a spiral-scanning path with one skip. Two selected candidates that have minimal and second minimal block distortion measures are obtained. Then a fine-tune step is taken around them to find the best one. Some analyses are given to approve the rationality of the approach of this paper. Experimental results show that, as oampared to APDS, the proposed algorithm can enhance the block-matching speed by about 30% while maintaining its MSE performance very close to that of it. And it performs much better than many other BMAs such as TSS, NTSS, UCDBS and NPDS.