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: 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 a video noise reducer, where pixel information is recursively filtered, with recursion being disabled at a disjuncture (caused by motion, planning, shot-change or otherwise), recursively filtered pixel information prior to disjuncture continues to be output until pixel information following the disjuncture has been recursively filtered to an appropriate degree of noise reduction.

Abstract: A method for reducing the deleterious effects of motion in a video signal process. The video signal process is conducted at high bandwidth without motion compensation and a like video signal process is conducted at low bandwidth without motion compensation to produce a low bandwidth control signal. A similar video signal process with motion compensation is conducted at low bandwidth to produce a low bandwidth motion compensated signal. The low bandwidth control signal and low bandwidth motion compensated signal are compared to produce an error signal which is subtracted from the high bandwidth video signal process. Video signal procession apparatus includes parallel high and low bandwidth paths.

Abstract: A group delay of a noise-reducing median filter for video or a video FIR filter is reduced by transferring filter contributions of fields in "time forward" to fields in "time past" with respect to an output sample point. No significant impairment is introduced by this time asymmetry.

Abstract: A video storage arrangement produces a continuous video signal representing a test pattern. One luminance frame store is provided and two chrominance frame stores. A selection can be made between NTSC, PAL and SECAM modes. Switches are provided for selecting between chrominance frame stores and between inverting and non-inverting mode. Depending upon the selected broadcast standard, these switches are driven from field and line clock signals to generate the required output field sequence in YC or composite form.

Abstract: A movement detector is included in television signal processing apparatus in order to improve the performance of the apparatus. The detector evaluates an absolute frame difference signal on a sample by sample basis and, after comparison with a threshold level signal in order to remove the effects of noise is fed to an isolated point removal circuit where samples deemed to indicate movement are compared with surrounding samples and if identified as isolated are ignored. Adaptive control is provided if the threshold, the isolated point removal circuit and a quantizer circuit for non-linearly altering the frame difference signal.

Abstract: A multiplexed analogue component (MAC) television signal is encrypted for transmission and reception by authorized recipients only by dividing the signal into blocks and reordering the blocks prior to transmission. The signal within each block remains in its original order. Preferably, the signal representing one line of video is split into blocks which are reordered within the line time to cause translation or rotation of analogue components. Alternatively a group of lines may be processed as a group to cause reordering of the analogue components between lines. The preferred arrangement does not split the blocks of analogue signals already present in the MAC signal. The receiver is arranged to receive information regarding the encryption technique with the television signal and to reorder the blocks constituting the received signal whereby to reconstruct the original signal.