Abstract: A storage mechanism utilizing a single data recorder from which multiple channels of compressed video data may be simultaneously accessed. The data access to and from the data recorder via a single data access path takes place at a higher data rate (f.sub.1, f.sub.2) than the data rate (f.sub.3, f.sub.4) at which that compressed data needs to be decoded to support a video signal. A video router is used to direct the reproduced data stored within two data channel buffers to respective JPEG decoders where they are decompressed into a signal suitable for driving two digital monitors. In operation, a segment of compressed video data for one channel is recovered from the data recorder and stored within one of the buffers from which it is continuously read at a lower data rate (f.sub.3, f.sub.4). The data recorder then cues to another part of the medium from which data for the second channel is reproduced and stored within another buffer. The process is then repeated.

Abstract: A hue control circuit receives a video signal at an input terminal in the form of alternating multiplexed color difference samples Cb and Cr. The video signal is multiplied in a multiplier by a factor cos .phi., .phi. representing a desired hue adjustment, and the resulting multiplied signal is supplied to an adder. The video signal is also subjected to order inversion by flip-flops and a buffer circuit as a result of which the order of corresponding pairs of samples Cb and Cr is reversed. The reversed-order video signal is multiplied in a second multiplier by one of alternating factors -sin .phi. and +sin .phi., and the resulting multiplied signal is supplied to the adder. The multiplied signals are summed in the adder to produce hue adjusted color difference samples Hb and Hr, where:Hb=Cb cos .phi.-Cr sin .phi.andHr=Cb sin .phi.+Cr cos .phi..

Abstract: A digital color corrector for a color component of a video signal is operable to effect gamma, gain and black level correction. The gamma correction k is applied to a multiplier receiving the input signal E. Black level correction B is applied to an adder, and further arithmetic circuits are provided together with gain correction A to implement the equation.delta.E=[k.multidot.E+(A-B-k)].multidot.E+Bwhich includes a good approximation of the gamma correction without the need to use log and anti-log circuits. The output .delta.E represents an offset correction signal to be added to the original color component signal.

Abstract: Apparatus for motion vector estimation in a television image uses a block matching technique with successive refinement of the motion vector estimate. The apparatus comprises a vector filter and a vector calculator.

Abstract: Apparatus for motion vector estimation in a television image using a digitized signal representing the image, comprises a vector filter and a vector calculator for determining motion in the image at points spaced a predetermined number of pixels horizontally and a predetermined number of pixels vertically by a block matching technique, thereby to derive motion vectors, and a sub-pixel motion estimator for refining the selection of the motion vectors by determining a sub-pixel offset representing motion between fields of the image not equal to an integral multiple of the spacing between pixels.

Abstract: Apparatus for reducing the number of motion vectors associated with a digital television image comprises a vector filter, a vector calculator and a vector processor for deriving for each block of pixels within the television image a plurality of motion vectors representing the most common motion vectors of pixels in the block, each of the plurality of motion vectors having associated with it a figure of merit based upon the weighted absolute difference of the motion vectors of pixels in the block, and a vector reducer for associating with the plurality of motion vectors, a further motion vector for the same position from the previous field and a further motion vector for the same position from the next field, each of said further motion vectors having associated with it a figure of merit, and for selecting a smaller plurality of motion vectors from the plurality of motion vectors and the further motion vectors in dependence on the figures of merit.

Abstract: Apparatus for processing motion vectors associated with a digital television image, comprises a vector filter and a vector calculator for deriving a plurality of motion vectors respectively representing the motion of pixels in a corresponding plurality of blocks of pixels in the image, a processor for distributing the plurality of motion vectors into groups, each group comprising motion vectors lying within a respective different predetermined range of magnitudes and directions, and a processor for substituting for the motion vectors in each of a plurality of the groups into which the largest number of the motion vectors fall, a single motion vector representing the motion vectors in the respective group.