Abstract: A method and apparatus are provided for video signal processing of sequences of digitized images originating from video (10) or film. A field grabber (12) receives the digitized images from the input and identifies the separate fields thereof. An image manipulation stage (14) combines fields as required and reduces the number of pixels per line and pixel lines in each image by applying horizontal and vertical compression; this stage also provides filtering and resizing of the image as required. Following encoding (16) of the compressed images, the encoded data stream may then be processed (18) into a form for recording onto, for example, an optical disc. By appropriate choice of the number of lines to which the image manipulation stage (14) reduces the image, discs playable on either PAL or NTSC standard equipment may be produced from a single image source.

Abstract: An apparatus for identifying automatically from an interlaced video recording the frames of an original cine-film sequence from which the video recording has been derived. The apparatus includes an evaluation for evaluating, for each successive pair of fields, a function measuring correlation between adjacent odd and even picture lines taken from the first and second fields of the pair, respectively; a comparator for comparing the correlation function of each field pair with that of at least one neighboring pair in the sequence; and a selector for identifying pairs with greater correlation than their neighbors as being derived from the same original film frame. The original frames are reconstructed and fed to an MPEG motion picture encoder to obtain high quality compressed video, Also provided is automatic scene cut detection which allows adaptive operation of the MPEG encoder.

Abstract: In the encoding of a frame (P3) in a digitised motion picture sequence, the frame is divided into blocks (A) of pixels and a motion vector (VA) found to predicts the contents of each block A from a block (A') in a previous frame (I0). Rather than evaluate many thousands of candidate vectors to find the best motion vector (VA), relatively few candidate vectors are evaluated, based on starting vector which is the estimated motion vector for a neighbouring block (LB(A)) in the same frame. To allow parallel processing of several pixel blocks, all the blocks of one row in the current frame are assigned to one processor (DSP), and a starting vector is obtained from a block (LB(A)) previously processed by the same processor. Further starting vectors are obtained if desired from neighbouring blocks (UR(B),DR(B)) in neighbouring frames of the sequence. The candidate vectors based on a starting vector may be very few in number, or may fill an area a few percent of the full search area.

Abstract: A communication system comprises a plurality of subscriber stations (51-1 to 51-n) each of which comprise a transmitter (3) and a receiver (4). A switching network comprising a selection switch (57) and a synchronous digital switching network (60) is connected to the subscriber stations (51-1 to 51-n) via separating and combining circuits (52-1 to 52-n) each of which comprise a transmitter (3) a receiver(4) and an interface unit (55). The transmitter (3) transmits a signal comprising a square wave frequency modulated signals which is modulated by a wideband (video) signal, on transitions of which short or long pulses are initiated in response to a data signal. The wideband and data signals are separated in the separating and combining circuits (52-1 to 52 -n) to enable the wideband and data signals to be separately processed in the switching networks (57,60).