Method and apparatus for determining motion vector using predictive techniques

A method for determining a motion vector, comprising:

• determining a searching point having a minimum SAD as the first predictive motion vector by performing a N search on the basis of a predetermining pixel;
• determining whether the first predictive motion vector is (0, 0);
• obtaining a searching point having a minimum SAD by performing a
• 15 N 2 n
• search on the basis of a predetermined pixel if the first predictive motion vector is not (0, 0);
• determining whether a distance between the searching point having the minimum SAD and (0, 0) is 1 pixel;
• determining a searching point having a minimum SAD as the second predictive motion vector by performing a M search on the basis of the minimum SAD if the distance is not 1 pixel;
• and
• determining the final motion vector by comparing the first and second predictive motion vectors.

A method for determining a motion vector, comprising:

• determining a searching point having a minimum SAD as a first predictive motion vector by performing a N search on the basis of a predetermining pixel between a current frame and a former frame;
• determining the first predictive motion vector as the final motion vector if the first motion vector is (0, 0);
• determining a minimum SAD among SADs by obtaining the respective 9 SADs by N/2 pixel search, N/4 pixel search, . . . , 1 pixel search on the basis of a predetermined pixel if the first motion vector is not (0, 0);
• determining a second predictive motion vector by M/2 search in case the minimum SAD is a minimum SAD obtained by a M pixel search (M≠1) and
• determining a searching point having a smaller SAD between the searching points corresponding to the first and second predictive motion vectors as the final motion vector.

A method for determining a motion vector, comprising:

• determining a first searching point using information obtained from a former frame and a current frame and establishing said first searching point as a first predictive motion vector by performing a first search on the basis of predetermined pixel;
• determining a second searching point using information obtained from a former frame and a current frame and establishing said second searching point as a second predictive motion vector by performing a second search on the basis of a predetermined pixel;
• and
• determining a motion vector by comparing the first predictive motion vector and the second predictive motion vector.

An apparatus for determining a motion vector, comprising:

• a means for determining a searching point having a minimum sum of absolute difference (SAD) as a first predictive motion vector by performing a N search on the basis of a predetermined pixel;
• a means for determining a searching point having a minimum sum of absolute difference as a second predictive motion vector by performing
• 17 N 2 n
• search on the basis of a predetermined pixel;
• and
• a means for determining a motion vector by comparing the first predictive motion vector and the second predictive motion vector.