Abstract: Audio visual or other equipment modules in a common enclosure are controlled through an SNMP control agent by interrogating module locations for the presence of an equipment module; determining an equipment type; determining a list of available control objects associated with that equipment type; associating values identified by equipment type and by control parameter with the control objects of equipment modules to be controlled; and communicating said values across a network.

Abstract: A method of compressing data representing a sequence of images in dependence upon data defining at least one region of particular interest within at least one image in the sequence includes causing data representing an image region that is not of particular interest to be more highly compressed than data representing an image regions that is of particular interest.

Abstract: A method of and apparatus for image analysis for picture loss detection in fields or frames in video or film content makes use of different correlation characteristics of picture images and non-picture images to detect picture loss. A measure of self correlation of a plurality of image data samples, and a measure of the correlation of the plurality of image data samples with a mean value are determined, and a positive detection of picture loss is based on a comparison between the two correlation measures.

Abstract: This invention concerns image analysis of video signals or data in order to detect prior, block-based processing, and to quantify block-related picture impairments. Adjacent samples of video data are high pass-filtered, rectified and auto-correlated to form an auto-correlation function. The auto-correlation function may be analysed to provide information regarding block size and other block artefact measures.

Abstract: A method of image segmentation using graph-theory techniques, in which pixels of an image are represented by the vertices of a graph. A minimum spanning tree is generated and edges of the tree are successively removed according to a morphological property to leave a spanning forest, trees of which correspond to segments of the image. Selection of edges for removal may depend on an energy function of a tree and on the energy function of trees created by removal of that edge.

Abstract: Monochrome images are detecting by analysing the skew of the statistical distribution of color difference values of pixels. A skew parameter is derived from an upper percentile, a lower percentile and a median value of the statistical distribution of color difference values and color is detected when the said skew parameter exceeds a threshold.

Abstract: A method for the automatic detection of fields or frames in film or video content having similar or substantially the same luminance or color component values, for example to detect black frames. Image sample values are assigned to a sample value range having a signed weight associated therewith, and a contribution to a discriminator function is determined for each sample range depending on the signed weight and the number of input samples in the sample value range. The discriminator function output is then compared with a threshold.

Abstract: A video mixer may be employed to form a transition between two video compositions, for example a fade or a wipe. A video storage device may be associated with the video mixer and plays out a video signal, the timing of which is controlled in dependence upon the progress of the transition made by the said video mixer.

Abstract: In a video encoder a prediction signal at a bit resolution of P is subtracted from an input signal received at a bit resolution of P+?, where P is typically 8 bits, and P+?, 10 bits. A transform is then performed on the result, the output of which transform being at a bit resolution of at least P+?. The transformed signal is quantised, and the quantised signal used to form the prediction signal. The quantised signal is then coded for downstream delivery. At a decoder, the process is inverted, preserving the extra ? bits input to the encoder.

Abstract: In a video encoder a prediction signal at a bit resolution of P is subtracted from an input signal received at a bit resolution of P+?, where P is typically 8 bits, and P+?, 10 bits. A transform is then performed on the result, the output of which transform being at a bit resolution of at least P+?. The transformed signal is quantized, and the quantized signal used to form the prediction signal. The quantized signal is then coded for downstream delivery. At a decoder, the process is inverted, preserving the extra ? bits input to the encoder.

Abstract: A video signal is analyzed to determine what compression coding decisions would be taken if the video signal were to be MPEG2 encoded. A representation of these coding decisions then accompanies the un-coded video signal for use in a downstream “dumb” encoding process. The coding decisions take the form of an MPEG2 bitstream and are embedded in Isb's of the video.

Abstract: A method of generating an orthogonally sampled video signal based on a line phase measure. In a first aspect the input signal is sampled by a clock locked to the average line frequency of a video input and the resulting samples are time shifted, optionally with or without interpolation, to an orthogonal sampling grid. In a second aspect input samples are taken and shifted to an orthogonal sampling grid according to a line phase measure. The line phase measure can be derived from a number of measurements or interpolated. In one embodiment a delay is employed so that a measure of a later sample is used to shift an earlier sample.

Abstract: In motion compensated standards conversion, an output video field is constructed from four input fields (two inner fields and two outer fields) by shifting pixel information from an outer field to the output field position in two stages, the first stage using a first motion vector between the outer field and the adjacent inner field and the second stage using a second motion vector being derived from a motion vector pointing from one inner field to the other inner field.

Abstract: In compression coding of picture sequences, a measure of picture difference is generated and compared with a picture difference threshold. The comparison is used in selecting between the use of predicted (P-pictures) and non-predicted has an initial value adapted to promote the use of an I-picture at or close to a scene change in the picture sequence, and changes in time in such a manner as to increase the probability of selection of a I-picture with an increase in the time since selection of the last I-picture.

Abstract: A method of de-interlacing a video signal by conducting three linear filtering operations on the input to produce three filtered signals, each linear filtering operation comprising the taking of a weighted sum of pixels; and multiplying together the three filtered signals to produce an output video signal.

Abstract: In video scratch repair, scratches are treated as additive pedestals which are constant or slowly changing along the scratch. For a given picture, these pedestals are estimated and subtracted from the video input to reveal original picture detail. The pedestal can be estimated by heavily filtering along the direction of the presumed scratch, the output of a prior art scratch detector.

Abstract: To enable a single programme in a multiple programme MPEG transport stream (MPTS) to be replaced seamlessly by a locally generated programme, the local coder received the MPTS as a reference signal and outputs transport packets in alignment with the packets of the programme to be replaced. Timing and other packet parameters are also copied.

Abstract: In video processing, a motion compensated process and an equivalent linear process are performed on an input signal, the processing errors of which are computed and compared. The comparison is then used to control a mix between the outputs of the two processes to produce an output signal.

Abstract: To enable a single programme in a multiple programme MPEG transport stream (MPTS) to be replaced seamlessly by a locally generated programme, the local coder receives the MPTS as a reference signal and outputs transport packets in alignment with the packets of the programme to be replaced. Timing and other packet parameters are also copied.