This paper presents the EPFL proposal to MPEG-4 video coding standardization activity 1]. The proposed technique is based on a novel approach to audiovisual data compression entitled dynamic coding. The newly born multimedia environment supports a plethora of applications which can not be covered adequately by a single compression technique. Dynamic coding… (More)
In this paper, benchmarking results of watermarking techniques are presented. The benchmark includes evaluation of the watermark robustness and the subjective visual image quality. Four different algorithms are compared, and exhaustively tested. One goal of these tests is to evaluate the feasibility of a Common Functional Model (CFM) developed in the… (More)
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 in a dynamic combination of multiple representation models and segmentation strategies.… (More)
Alpha planes are used to compose objects in order to build synthetic images. They contain the shape and the transparency of the diierent objects. The scene is composed by superimposing objects in a given order. The alpha planes specify the transparencies of the objects. In order to independently compress these objects, the alpha planes must also be coded.… (More)
MPEG-4 aims at providing standardized core technologies allowing efficient storage, transmission and manipulation of video data in multimedia environments. In order to achieve this broad goal, rather than a solution for a narrow set of applications, functionalities common to clusters of applications are under consideration. The encoded representation, along… (More)
This paper deals with the mode decision in an MPEG-2 framework. An algorithm for mode decision is introduced. This algorithm is based on a rate-distortion criterion and takes into account the temporal dependency of the frames. This approach can allow a quality gain of more than one dB compared to the Test Model 5 (TM5) mode decision algorithm.