Abstract: An image processing system operates on first and second image data (V and Bg) to produce data defining a combined image. The first image data (V) represents a keyed image comprising a first object (F) keyed over a portion of a first background (B) in accordance with keying data (K). The second image data (Bg) represents a background. The system is arranged so that the second image data (Bg) is weighted by respective control data (.alpha.) related to said keying data (K) before being combined with the first image data (V). In another embodiment the first image data represents a second object independently keyed over the keyed image in accordance with second keying data and the control data is further related to the second keying data. In a further embodiment the first image data represents an image derived by cross fading between the first keyed image and a second keyed image.

Abstract: A system in which a characteristic of individual picture points is provided to an accuracy of m binary bits but conveyed by n bits, where n is less than m. The value of a lower order bit of the n bit signal is switched to cause said binary value to represent, for any one picture point, either a value above or a value below the original value. The new values are distributed without order among the picture points with a probability dependent upon the value of the (m-n) lowest order bits of the desired value.

Abstract: A system for manipulating video image signals, in which digitized composite video signals (i.e. D2 digitally encoded PAL or NTSC) are converted to component video signals (i.e. luminance and color difference signals) allowing selected pixels to be modified. In addition, the unconverted composite video signals are also stored and a key signal is generated which indicates which of the converted (i.e. component) pixels have been modified. An output signal is then produced by combining the manipulated signals and the unmanipulated signals in proportions determined by said key signal.

Abstract: A system in which a characteristic of individual picture points is provided to an accuracy of m binary bits but conveyed by n bits, where n is less than m. The value of a lower order bit of the n bit signal is switched to cause said binary value to represent, for any one picture point, either a value above or a value below the original value. The new values are distributed without order among the picture points with a probability dependent upon the value of the (m-n) lowest order bits of the desired value.

Abstract: A video signal processing system in which a number of video image signals are combined to provide an output which is such that where several objects of the input images overlay so they appear to be at different distances. Each input video signal is provided with a priority signal and a series of contests are held within the processor so that the final image consists of the two video signals with the highest priority. A key signal is provided for the video signal with the highest priority.

Abstract: A video processing system is disclosed having a store (1) into which video signals, in the form of a sequence of pixels, are written into and read out of in response to common fixed clocking pulses, although the input video signal is synchronized independently of the output video signal. The phase of the pixels at the input to the store, and also the phase of the line and field synchronizing pulses, is adjusted to correct sub pixel phase error between input and output so that the common pixel clocking pulses can be used thereby substantially reducing cross talk between the input and output signals.

Abstract: A processing system includes a processor 10 and frame store 11. Both the frame store and processor are under the control of address mechanism 12. An incoming pixel is processed with previously stored information and the proportion of processed information restored is controlled to prevent errors in picture information density as store location may be accessed a number of times in a frame period. The addressing mechanism 12 can generate the desired information from address information which is only provided on some of the store locations and which is only updated over more than one frame period. The mechanism includes spatial and temporal interpolators to effect this operation.

Abstract: A video signal processing system which produces the same output image as the input image but with a size and/or shape change applied to it. The incoming video signals are written into the frame store in sequence but read out in an order determined by the output image required. When compressions in the image occurs the luminance signals are filtered prior to writing in the store.

Abstract: A processing system includes a processor 10 and frame store 11. Both the frame store and processor are under the control of address mechanism 12. The addressing mechanism 12 can generate the desired information from address information which is only provided on some of the store locations and which is only updated over more than one frame period. The mechanism includes spatial and temporal address interpolators to effect this operation.

Abstract: A processing system for effecting angular displacement of at least part of a television picture. The picture is subdivided into picture areas each containing a plurality of picture points and a number of storage devices respectively receive information on each picture point within the area at a designated storage location. On read out, the location of a particular area is accessed by means of a picture point and line counter in a single read operation. Information on particular picture points within the area is selectively made available for interpolation via latches to allow construction of the displaced picture. The area accessed for read out can be modified relative to writing into the store in order to cope with any selected degree of displacement.