Abstract: A starting contour is defined surrounding around an elementary object delimited by a natural contour in a video image. On the basis of the starting contour, an original active contour is defined, formed by a set of nodes distributed on this starting contour, each node being formed by a point belonging to this starting contour and by an elastic energy function representative of the distance separating this node from a neighbouring node. With regards to a set of reference values representative of the contour of this object, the active contour is subjected to a convergent deformation under a blocking condition, by displacing at least one of the nodes of the original active contour toward the natural contour of the elementary object to generate a current active contour iteratively subjected to this convergent deformation.

Abstract: In a multichannel encoding method for encoding digitized pictures, in particular digitized stereoscopic television pictures, the digitized pictures are processed in different channels comprising at least a movement estimation channel to provide digitized picture encoding data. A particular processing channel is chosen on the basis of this encoding data. In the movement estimation channel an input digitized picture is divided into blocks of pixels to provide a movement vector for each block and an error for each block pixel. For each block, a set of values is calculated relative to a block mean error, a block error standard deviation, a block error mean deviation and an amplitude of the block movement vector to choose the particular processing channel assigned to said block on the basis of the set of values.

Abstract: A three-dimensional television system uses a method of processing and transmitting a sequence of pairs of stereoscopic television images by means of a transmission link comprising and analog video channel associated with a digital channel to reconstitute at the receiving end a compatible image or a three-dimensional image. The analog video channel transmits a compatible video image formed by multiplexing image items of righthand and lefthand images of pairs of stereoscopic images from the sequence.

Abstract: A demodulator including a Hilbert transformer (20), a carrier regenerating circuit (30), a first delay line (35), a second delay line (36), a first switching device (38), a second switching device (39), a first multiplier (40), a second multiplier (42), a second adder (44), a third switching device (46), a third multiplier (48), a fourth switching device (50), a fourth multiplier (52), a second adder (54) and a divider circuit (60). This demodulator is able to demodulate either a frequency modulated signal, or a signal with double amplitude modulation in quadrature and with suppressed carrier.

Abstract: A starting contour is defined surrounding around an elementary object delimited by a natural contour in a video image. On the basis of the starting contour, an original active contour is defined, formed by a set of nodes distributed on this starting contour, each node being formed by a point belonging to this starting contour and by an elastic energy function representative of the distance separating this node from a neighbouring node. With regards to a set of reference values representative of the contour of this object, the active contour is subjected to a convergent deformation under a blocking condition, by displacing at least one of the nodes of the original active contour toward the natural contour of the elementary object to generate a current active contour iteratively subjected to this convergent deformation.