Abstract: The invention relates to a method of coding a sequence of pictures using a segment operation of each of the pictures followed by a coding operation of each of the obtained successive partitions, and to a corresponding system. The system includes a projection circuit (11), for estimating on the basis of the mesh defined for a previous picture a projected mesh made of polygons and corresponding to the current picture, a mesh coding circuit (12,13,14,15) for coding motion and texture associated to the projected mesh, and a texture error detection and coding circuit (16,17).

Abstract: The invention relates to a method intended to automatically create a description of a video sequence—i.e. its table of contents—by analyzing the video sequence. First is a temporal segmentation of the video shots of the sequence, using camera motion parameters. This segmentation uses a similarity criterion involving, for sub-entities of each shot, the level of homogeneity of these sub-entities on the motion parameters of the camera used to acquire the original images and generate the bitstream constituting the processed sequence.

Abstract: The invention relates to an image sequence coding method comprising a segmentation of each image into partitions made of regions, an estimation and compensation of the motion of these regions between two partitions, and a region contour and texture coding step. The proposed motion estimation step of this method is carried out in a loop circuit (91, 92) in which, after a definition of the mode of transmission of the regions, a particular coded signal is generated for the background regions of the partition, said signal including an order information, indicating a priority between contiguous regions, and an associated updated motion information. The implementation of this method reduces drastically the computational load before the contour coding. The invention also relates to the corresponding decoding method and system.

Abstract: The invention relates to a method intended to automatically create a description of a video sequence—i.e. its table of contents—, by means of an analysis of the sequence. The main steps of the method are a shot detection, a sub-division of these shots into sub-entities called micro-segments, and the creation of the final hierarchical structure of the processed sequence. According to the invention, the shot detection step computes the mean displaced frame difference curve, detects the highest peaks of said curve, removes, by filtering, some negative or positive peaks, extracts markers, and propagates them on the curve.

Abstract: The invention describes a method and system for coding a sequence of pictures using an active triangular mesh coding scheme and a partition tree. It subdivides the current picture into a mesh of blocks with nodes located on high gradient points, further subdividing the blocks into two triangles. The system comprises a projection circuit, for estimating on the basis of the mesh defined for a previous picture a projected mesh made of polygons and corresponding to the current picture, a mesh coding circuit for coding motion and texture associated to said projected mesh, and a texture error detection and coding circuit. Applications are very low bit rate coding, multimedia applications.

Abstract: The invention relates to a method of coding a sequence of pictures using a segmentation operation of each of the pictures followed by a coding operation of each of the obtained successive partitions, and to a corresponding system. The system includes a projection circuit (11), for estimating on the basis of the mesh defined for a previous picture a projected mesh made of polygons and corresponding to the current picture, a mesh coding circuit (12, 13, 14, 15) for coding motion and texture associated to the projected mesh, and a texture error detection and coding circuit (16, 17).

Abstract: The invention relates to an image sequence coding method comprising, after a segmentation of the images into partitions with associated labels, the main steps of coding the contours of the regions sent in intra-frame mode, generating a compensated partition, and computing from said compensated partition and the current one an error partition that is then coded. While reducing the computational load, this method, that allows to transmit information about a time-varying partition with the help of the motion of the pixels, is preferably carried out by means of an encoding sub-assembly coprising an intra coding device (181), a compensating device (182), and an inter coding device (183) extracting and coding partition errors defined by an extraction of error regions where compensated and current labels are different.

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: This relates to a filtering method for processing an image sequence, including for each image parallel binarizations of the gray levels, provided to define a tree structure made of a father node (c.sub.0.sup.1) corresponding to a background (A0) and of successive child nodes (C.sub.h.sup.k) corresponding to associated connected components (B1, D1, F1, C2, E2, G2) and a decision on the elimination or the preservation of each node (C.sub.h.sup.k), followed by an assignment of a gray level value to each picture element. This type of filtering offers the advantage of simplifying the images as well as perfectly preserving the contours, and the decision is based on various proposed simplification criteria, among which the motion-oriented one is particularly attractive.

Abstract: The apparatus performs a processing operation on the signal in a transmission system, this signal conveying analog luminance and chrominance information components associated with periods of the coded digital signal. A receiver in a MAC television system is, for example, such a device. The device for recovering the d.c. component includes encoding member (4) which, from the decoded digital signal, realizes an encoding operation of the type used for the creation of the received signal, an estimation circuit for the d.c. component (6) calculating the estimation from the difference between the received coded signal and the recovered coded signal by the encoding member, this estimation constituting d.c. component correction signal, and a subtraction circuit (9) which, from the digital signal received, subtracts the d.c. component correction signal throughout the duration of a line. The apparatus also includes, downstream of the device (6) which supplies the d.c.

Abstract: A circuit for decoding coded frequency modulated signals eliminates perturbing effects of noise pulse signals by coupling the signal to be detected through a filter having a transfer function that is related to the conjugated transfer function of the frequency modulation deemphasis filter, the spectrum of the noise pulse, the spectral power density of the signal to be demodulated, and the spectral power density of the noise. A comparison circuit provides the signal at the output of the filter when the output signal exceeds a threshold level. A decision circuit, which provides signals representative of the temporal position and polarity of the noise pulses to the correction circuit, is coupled between the comparison circuit and a circuit for generating noise correction pulses. The noise correction pulses are coupled to the decoder with the output signal of the detector to eliminate the effects of the noise pulse.

Abstract: A device for decoding a transmitted sequence of duobinary encoded signals, which provides as an output a sequence of binary signals which most probably matches the transmitted sequence of duobinary encoded signals, estimated as a function of the duobinary signals actually received by the device.