OVERLAPPING BLOCK TRANSFORM - WINDOW DESIGN, FAST ALGORITHM, AND AN IMAGE-CODING EXPERIMENT

In this paper, window design and fast algorithm for the overlapping bl ock transform (OBT) of size NxL are presented, The presented algorithm for the OBT reduces the calculation complexity to an NxN transform wi th a fast algorithm and a simple preprocessing including windowing, A signal-independent window optimization strategy is introduced for imag e coding application, Results for a first-order Markov model and an im age coding experiment show, that the coding gains of the optimized OBT 's increase and blocking effects decrease with increasing window lengt h L. A comparison with DCT-coding shows that the OBT, whch has a sligh tly increased realization complexity, provides higher coding gain and a significant blocking effect reduction.