Efficient motion-compensated coding for low bit rate video applications.
Item
-
Title
-
Efficient motion-compensated coding for low bit rate video applications.
-
Identifier
-
AAI8821116
-
identifier
-
8821116
-
Creator
-
Puri, Atul.
-
Contributor
-
Adviser: Donald L. Schilling
-
Date
-
1988
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Engineering, Electronics and Electrical
-
Abstract
-
In this thesis, we develop efficient, image-compression techniques towards low bit-rate, full-motion, video-conferencing application. Motion-compensation techniques seek to detect, estimate and compensate for movement of the objects in a scene, and can improve the coding efficiency significantly. We therefore present an efficient search technique, that reduces the computations necessary for estimating motion by block-matching. We also propose several approaches to improve performance, reduce complexity of computations, and reduce overhead. Statistical properties of motion-compensated frame-differential (MCFD) signal, are then investigated; and provide a basis for developing coding algorithms.;A basic transform-domain scheme for coding MCFD signal is investigated, and choices for transforms explored. The basic (single) transform scheme is then modified to allow multiple-transform coding. In this scheme, depending on the characteristics of the block being coded, selection of the transform can be made from a small set of predecided transforms, on a block-by-block basis.;A variable block-size (VBS) scheme is proposed for coding MCFD's, and introduces adaptivity to improve performance. Two configurations are tested: the first, uses blocks for motion-estimation and sub-blocks for coding, whereas, the second uses sub-blocks for motion-estimation and coding. The performance of, both the transform-domain and pel-domain algorithms are compared with and without the VBS approach.;The concept of cluster and the method of cluster coding is then introduced; this method encodes significant pels that group together in a MCFD block in pel-domain. For blocks with sharp pulsive-transitions in MCFD's, transform coding schemes may require excessive bits. A hybrid scheme, combining transform and cluster coding techniques, is therefore recommended and its performance evaluated.;A complete-coder that uses fixed step-size is simulated, and bit-rate including motion and other overheads computed. A strategy useful for controlling the buffer status is then outlined. A complete-coder that includes buffer-feedback to allow buffer control is simulated.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
