Fast algorithm for vector median filters with vector distance computation

A new fast algorithm was proposed to improve the computation speed of the classic vector median filter (VMF) and their extension. The vector distance matrix was obtained in filtering window. The relation of current pixel's and neighbors' filtering windows was analyzed, and a new ordering rule was defined for the pixels in the filtering window. The most part of vector distance in current vector distance matrix can be obtained from the nearby ones'. The new approach has the same filtering results with the original algorithm and can be used for any kind of window size. After giving the filtering results of several original vector median filters and the fast variants, the experiments show that the proposed method could decrease by about 50% to 70% of actual computation time when it is applied to those filters with filtering window size in common use.