Directional cross hair search system and method for determining a preferred motion vector
View Patent ↗A system and method for determining a preferred motion vector is provided, which may be used to estimate motion in a series of video image frames. The system may include a video encoder having a motion vector selector. The motion vector selector may include a first generator to generate a cost associated with motion vectors in a first direction, a selector to set a cross over point corresponding to a lowest cost motion vector in the first direction, a direction indicator to sample a set of motion vectors about the cross over point to select a preferred direction, and a second generator to generate a cost associated with the motion vectors in the preferred direction. The method may include determining a final motion vector having the lowest cost within a search window.
1. A method of selecting a preferred motion vector, comprising:
generating a cost associated with each of a first plurality of motion vectors along a first direction;
determining a cross over point associated with a lowest cost motion vector from among the first plurality of motion vectors;
determining a motion vector plane associated with the cross over point;
generating a cost associated with each of a predefined number of sample motion vectors about the cross over point;
generating a cost associated with each of a second plurality of motion vectors along a second direction associated with the motion vector plane;
determining an orientation of the second direction associated with the motion vector plane based on the generated costs; and
selecting a lowest cost motion vector from among the second plurality of motion vectors.
2. A method of selecting a preferred motion vector according to claim 1 in which generating the cost associated with the predefined number of sample motion vectors includes generating the cost of at least one sample motion vector in each of a predefined number of directions extending from the cross over point.
3. A method of selecting a preferred motion vector according to claim 2 in which determining the orientation of the second direction associated with the motion vector plane includes selecting a lowest cost orientation corresponding to at least one of the predefined number of directions extending from the cross over point.
4. A method of selecting a preferred motion vector according to claim 3 in which selecting the lowest cost orientation includes:
summing costs of the at least one sample motion vector for each of a plurality of opposite directional pairs extending from the cross over point; and
comparing the summed costs for each pair to each other.