Question

How are motion vectors computed? Please analyze on three kinds of search algorithms and analyze their expected performance.

Answer 1

Three kinds of algorithm:

DFA: This is an implementation of the differential method of cafforio and rocca .in this case the moving area,was to set a block of 16*16 pels

PRA : This is an implementation of the pel-recursive algorithm of netravali and robbins.in this case the motion ector of the previous pel in the line was taken as the intial motion estimate,the current pel,the update step size was set to 1/1024,the update term was calculated and averaged over an area of 3*3 pels centered around the current pels,and five iteraions were pergformed per pel.

BMA: This is an implementation of a full search block-matching algorithm.in this case,the block size was 16*16 pels and the matching criterion was the SAD.