Dynamic video coding-an overview

In this paper, we present an overview of the dynamic coding approach, together with recent developments carried out in this framework. Dynamic coding is a general approach to the problem of visual data representation in the context of multimedia. This approach consists of a dynamic combination of multiple representation models and segmentation strategies. Given an application, these two degrees of freedom are assembled so as to yield a specific profile which meets the specifications dictated by the application. The data is represented as the union of data segments, each described within a locally appropriate representation model. In order to illustrate this approach, a video compression system, based on the principles of dynamic coding, is proposed in the context of video-telephone/conference applications. This algorithm has been submitted to the MPEG-4 committee as a proposal for the first round of tests in November 1995. Recent developments have been added: in particular, a procedure enabling the generation of an object-oriented scalable bitstream is presented here. In order to reduce the blocking artifacts which are noticeable at high compression ratios, a post-processing technique is proposed