A wavelet codec with overlapped motion compensation for very low bit-rate environment

Author

Katto, Jiro ; Ohki, Jun-Ichi ; Nogaki, Satoshi ; Ohta, Mutsumi

Author_Institution

Inf. Technol. Res. Lab., NEC Corp., Kanagawa, Japan

Volume

4

Issue

3

fYear

1994

fDate

6/1/1994 12:00:00 AM

Firstpage

328

Abstract

The paper describes theories on overlapped motion compensation and their applications to a wavelet codec aimed for the very low bit-rate environment below 64 kb/s. The theories are concerned with the evaluation of prediction efficiency improved by overlapped motion compensation and also its smoothing effect on the discontinuities at block boundaries encountered when motion vectors do not coincide among neighboring blocks. They contribute to determine the optimum window shape for overlapped motion compensation in a developed wavelet codec, which suffers from reduction of coding efficiency when there are such discontinuities in a signal to be transformed. Regarding the wavelet codec, a new scanning method of transform coefficients and alternate use of normal and spatially-reversed basis functions for the cascaded wavelet transform are introduced. Finally, the implementation of the codec on a video image signal processor (VISP) is discussed

Keywords

codecs; filtering and prediction theory; image coding; motion estimation; wavelet transforms; VISP; basis functions; block boundaries; cascaded wavelet transform; coding efficiency; discontinuities; motion vectors; optimum window shape; overlapped motion compensation; prediction efficiency; scanning method; smoothing; transform coefficients; very low bit-rate environment; video image signal processor; wavelet codec; Codecs; Discrete cosine transforms; Discrete transforms; Motion compensation; Motion estimation; Shape; Signal processing; Smoothing methods; Video coding; Wavelet transforms;

fLanguage

English

Journal_Title

Circuits and Systems for Video Technology, IEEE Transactions on

Publisher

ieee

ISSN

1051-8215

Type

jour

DOI

10.1109/76.305877

Filename

305877