A variety of encoding methods are available in literature:

Partial Distortion search (PDS)[23], nearest neighbor search

algorithm based on orthonormal transform (OTNNS) [24].

Partial Distortion Elimination (PDE) [25], Kekre’s fast search

algorithms [26], [27], [28] etc., are classified as partial search

methods. All these algorithms minimize the computational cost

needed for VQ encoding keeping the image quality close to

Exhaustive search algorithm.