Abstract: In order to reduce the digital data throughput, the transmission system comprises means for determining, for each image, in the set of speed vectors, a subset containing the vectors which are encountered most frequently in this image, and means for digitally transmitting, once per image, the characteristics of all the vectors of this subset, and if the speed vector of an image part to be transmitted is an element of the subset, it is defined by reference to the subset, while, if it is not an element of the subset, another transmission mode is used for the current image part, being a mode in which the speed vector is not used, but in which the analog video data are transmitted with a lower spatial definition but with a higher frame rate.

Abstract: An arrangement for encoding two dimensional information grouped in periodical information clusters, the arrangement being comprised of a variable length encoding stage, reconstruction stage, a movement estimating stage and the prediction stage. The movement estimation stage is adapted to supply from the input signals, movement information related to the movement between input signals of the same row or of opposite rows. The reconstruction stage provides a path for additional processing of the signals when the input signals provide additional information components.

Abstract: An arrangement for estimating motion in a sequence of picture comprising first, second and third picture stores (10, 20, 30) arranged in series to ensure the permanent storage of three respective consecutive pictures denoted, for example, by their rank 2k, 2k+1, 2k+2 in the sequence of pictures, and a recursive displacement estimator (40) receiving the outputs of said first and third picture stores to update at each extension of the classifying tree the displacement vectors relating to the junctions of the tree and the send them to a delayed-decision circuit (50), said delayed-decision circuit receiving said updating information and also the outputs of said picture stores and supplying, for each block preceding the current block of L blocks, the information of the group in which this preceding block and the information of the corresponding displacement vector is finally classified.

Abstract: Method of and arrangement for converting the temporal rate of high definition television pictures, in accordance with which, after the division by two of the line period in a line period changing circuit (100) and storing the fields of the picture for a working period corresponding to one period with the aid of field memories (90, 80, 70, 311), these fields are processed in parallel by simple field repetition, by taking a motion compensated half-sum and by filtering and, by the selection of one of the three field sequences thus processed e.g. with the aid of digital assistance signals provided in the HD-MAC high definition television standard. This method and device can be used in high definition television receivers.

Abstract: A method of estimating motion in a picture sequence in which each picture is divided into blocks defined by two coordinates (m,n), respectively, indicating the row of the picture line in which the block is present and the row of the block on this m-th line. This method provides for:defining three groups for the blocks classified in fixed blocks, moving blocks and exposed blocks, in which groups the blocks are classified with a delay in accordance with the scanning of the picture by examining a given number of possible group sequences;constructing a classification tree whose 3.sup.

Abstract: Method of and device for estimating motion in a picture sequence, for use in compression of information to be transmitted or registered are disclosed. The method consists of: preserving the preceding picture with respect to the current picture; defining tree groups for the elements classified in fixed elements, moving elements and exposed elements, in which groups the elements are classified with a delay of L elements according to scanning of the picture; constructing a classification tree whose 3.sup.