Strategies for Fast True Motion Block Matching

Block matching is a widely used method for fast motion estimation. Although using a very simple motion model, which does not fit most real world video material, many motion compensating video compression algorithms use block matching because of its speed. Applications based on true motion vector estimates often use an optical flow algorithm because of their higher need for accuracy at the expense of increased computing time. This paper presents a modified block matching algorithm suitable for true motion applications. A modified full search will be used on a cost function consisting of SAD and a vector field smoothing term. Several strategies as search center prediction, spiral search, early search termination and multilevel successive elimination are implemented to keep the computational demand low. This way, high-quality estimates can be computed in real-time.