Abstract: A video encoder and decoder are provided for processing a sequence of animated pictures in such a way that an interactive game, such as a puzzle for instance, may be played. Each picture of a movie sequence is divided into a predetermined number of pieces that are then randomly coded (according to the MPEG-4 standard), transmitted and/or stored, decoded and displayed. It is then possible to play with the pieces to reorder them while they are in motion (with possible associated audio), according to predefined rules and ends of scenarios. The left and right buttons of a mouse, or a similar control device, are used to displace either one piece, or a group of attached pieces respectively, in order to verify if the proposed location for a piece is free and possible (no contradiction with any other surrounding piece) and then to drop said piece on the new spot, or, on the contrary, if some contradiction is detected, send back the piece (or, respectively, the group of attached pieces) to its previous location.

Abstract: The invention relates to a method and system for coding segmented pictures, and to corresponding decoding method and system. In the coding system, a first sub-system defines the time evolution of said segmented pictures, or partitions, and a second one encodes both contours and textures of the regions of the successive partitions. The time evolution definition leads to a partition tree (PT) from which regions are extracted during an analysis step (AS) in order to form a decision tree (DT). A decision operation allows to select during a choice step (CS) distinct regions R.sub.S from various levels of said partition tree, in order to construct an optimal final partition (BFP) and, simultaneously, to choose the coding technique (BCT) that is the best one for each region of said optimal partition. Reciprocally the decoding method and system comprise means for defining the coding strategy chosen for each of said regions and decoding correspondingly the coded information.

Abstract: The invention relates to an image sequence coding method in which images are segmented and coded with respect to their contours and textures. The texture coding step is carried out by means of a new technique relying on a wavelet decomposition of the images, called quincunx bidimensional wavelet transform and adapted to a region-based coding scheme, for applications allowing to reach very low bit rates while keeping a good image quality.

Abstract: The invention relates to an image sequence coding method in which images are segmented and coded with respect to their contours and textures. The texture coding step is carried out by means of a lattice vector quantization method adapted to region-based coding schemes where regions have arbitrary shapes, for applications allowing to reach very low bit rates while keeping a good image quality.

Abstract: Images having a moving pattern against a fixed or quasi-fixed background are segmented by determining a silhouette of the moving pattern, and forming a segmentation image filling the silhouette. On a pixel-by-pixel basis, differences are determined between the current image and previous images of a sequence, and compared with a threshold to form a binary image of background and useful zone. The boundaries of the useful zone are regularized, and irregularities in the useful zone and in the background are suppressed. A segmentation image is then formed within the silhouette.

Abstract: A coding subassembly for images composed of at least one moving pattern against a fixed or quasi-fixed background, including circuits for constructing a base model representative of the useful zone of the said images, a coding circuit, and an associated decoding subassembly. The model constructing circuits include circuits for initial calibration and adaptation of the model and a circuit for determining the movement of characteristic points taken from the useful zone and a circuit for selecting at least one zone of particular interest inside the useful zone and determining its movement. The coding circuit includes a circuit for coding output signals from the initial calibration circuit, and a circuit for correcting any shifts in luminance or chrominance in zones alongside the borders of the said zone(s) of interest observed on either side of these borders.