Abstract: A method and a device for coding and decoding a sequence of images or pictures is disclosed. One exemplary embodiment disclosed codes by dividing each picture into blocks of picture elements. Each element of a block being represented by a digital value. Two types of coding are utilized in order to reduce the amount of data; inter-coding, which takes into account a corresponding block in a previous picture and intra coding, which is independent from a previous picture. Blocks being thus coded so that a further reduction of data is obtained by transmitting high spatial frequencies with less weight than low spatial frequencies. This is accomplished with the use of weighting coefficients. Weighting coefficients are variable as a function of the quantity of information to be transmitted.

Abstract: A method and a device for coding and decoding a sequence of images or pictures is disclosed. One exemplary embodiment disclosed codes by dividing each picture into blocks of picture elements. Each element of a block being represented by a digital value. Two types of coding are utilized in order to reduce the amount of data; inter-coding, which takes into account a corresponding block in a previous picture and intra coding, which is independent from a previous picture. Blocks being thus coded so that a further reduction of data is obtained by transmitting high spatial frequencies with less weight than low spatial frequencies. This is accomplished with the use of weighting coefficients. Weighting coefficients are variable as a function of the quantity of information to be transmitted.

Abstract: A method and a device for coding and decoding a sequence of images or pictures is disclosed. One exemplary embodiment disclosed codes by dividing each picture into blocks of picture elements. Each element of a block being represented by a digital value. Two types of coding are utilized in order to reduce the amount of data; inter-coding, which takes into account a corresponding block in a previous picture and intra coding, which is independent from a previous picture. Blocks being thus coded so that a further reduction of data is obtained by transmitting high spatial frequencies with less weight than low spatial frequencies. This is accomplished with the use of weighting coefficients. Weighting coefficients are variable as a function of the quantity of information to be transmitted.

Abstract: A method and a device for coding and decoding a sequence of images or pictures is disclosed. One exemplary embodiment disclosed codes by dividing each picture into blocks of picture elements. Each element of a block being represented by a digital value. Two types of coding are utilized in order to reduce the amount of data; inter-coding, which takes into account a corresponding block in a previous picture and intra coding, which is independent from a previous picture. Blocks being thus coded so that a further reduction of data is obtained by transmitting high spatial frequencies with less weight than low spatial frequencies. This is accomplished with the use of weighting coefficients. Weighting coefficients are variable as a function of the quantity of information to be transmitted.

Abstract: A method and a device for coding and decoding a sequence of images or pictures is disclosed. One exemplary embodiment disclosed codes by dividing each picture into blocks of picture elements. Each element of a block being represented by a digital value. Two types of coding are utilized in order to reduce the amount of data; inter-coding, which takes into account a corresponding block in a previous picture and intra coding, which is independent from a previous picture. Blocks being thus coded so that a further reduction of data is obtained by transmitting high spatial frequencies with less weight than low spatial frequencies. This is accomplished with the use of weighting coefficients. Weighting coefficients are variable as a function of the quantity of information to be transmitted.

Abstract: The invention relates to an adaptive method of encoding and decoding of a series of pictures by transformation, the encoding consisting in:

Abstract: The disclosed method comprises a learning phase, during which the object zone to be recognized, selected in a learning image, is modelized, and a recognition phase during which the modelized zone is compared with image zones of a same size taken taken from the images to be processed.

Abstract: The disclosed method consists in:method for estimating the motion of at least one target in a sequence of images, including: coefficients transformed by the Fourier transform;computing a matrix called a phase correlation matrix, each coefficient of which is equal to the product of a transformed coefficient of a first image, by the conjugate of a homologous transformed coefficient of a second image, divided by the square of the modulus of this product;computing an inverse transformed matrix of the phase correlation matrix, in applying the inverse Fourier transform;searching, among the coefficients of the inverse transformed matrix, for those coefficients having the greatest moduli;then estimating a translation vector for each target and a translation vector of the image background, on the basis of the order of the row and of the order of the column in which there are respectively located the coefficients having these greatest moduli.

Abstract: A device for computing 16 mono-dimensional direct cosine transforms from 16 luminance values having an input memory. A first computing device delivers respectively two values of the form A+B and (A-B).times.D, where A and B are two values applied respectively to two inputs of the first computing device and where D is a predetermined coefficient. A first intermediate value storage device uses the first computing device for 32 similar operations. A second computing device delivers a value of the form E+G, where E and G are two values applied consecutively to the input of the second computing device. A second intermediate value storage device reuses the second computing device for 17 additional operations. Finally, a device changes the order of the transformed values.

Abstract: This process uses a bidirectional transformation by blocks for images representing highly animated scenes and also uses a differential coding of the transformation coefficients when the pictures show slightly animated scenes. The coding device mainly comprises a cosine transformation device, a subtractor, and inter-image decoding device, a multiplexer, a device for discriminating the blocks showing highly animated scenes and blocks showing slightly animated scenes. The latter device controls the multiplexer. The subtractor and the decoding device make it possible to calculate the difference between each transformation coefficient and the homologous coefficient of the homologous block in the preceding picture. Moreover, a weighting device makes it possible to transmit with a larger number of bits the coefficients or coefficient differences corresponding to the low spatial frequencies of the images.