Abstract: A video image processing system comprises an input cache store for temporarily storing input video data, compressors for compressing image data from the input store and an output store comprising multiple storage areas of known fixed size for storing respective files of compressed data from the compressors. The compressors are arranged to compress each image of the input video data to a given initial degree to produce respective data files. A processor compares the number of bytes in each data file with the known size of one storage area in the output store to determine whether the data file will occupy a predetermined proportion of said storage area. In the event that the data file will not occupy said predetermined portion of said storage area, the processor causes one of the compressors to effect one or more repeat compressions to a different degree in order to produce a data file of a size which will occupy said predetermined proportion of said storage.

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 creating high resolution video images for later use in printing or the like. The operator draws with a stylus on a touch tablet (28) and video signals are processed to produce a high resolution image corresponding to what is drawn, the signals being stored in a high resolution store (25). While the processing of the signals progresses certain signals are copied to a lower resolution viewing store (26) and these signals read to a display (27) where the image can be viewed by the operator. In one example the store (25) is notionally divided into areas and when the signals representing a stroke drawn by the operator are present in an area the whole area is copied to the viewing store. Typically about four areas need to be copied in a frame period so the stroke drawn by the operator can be seen as he is drawing it. The image on display (27) may be a low resolution version of the whole image or a high resolution version of part of the image.

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: Sources of video signals representing an object (e.g. an aircraft), optionally movable, and a scene provide data stored in frame stores (b 1,5). Distance (optionally variable) from the observer of the object and near and far distances at transitions between features in the scene are stored respectively in frame store (4) and (7a, 7b). Within the boundaries of the object and in the neighborhood of the lines of transition, between features of the scene, quantities stored in object and scene stencil frame stores (3, 6) vary from 0 to 1. All frame stores are read simultaneously, driven by a microprocessor (2), the picture point scanning element sequentially. A comparator (11) compares distances, and the results of the comparison, together with the values stored in the stencil frame stores, determine the tone displayed at each element. Near features obscure distant ones, and sharp transitions are softened.

Abstract: A system for creating high resolution video images for later use in printing or the like. The operator draws with a stylus on a touch tablet (28) and video signals are processed to produce a high resolution image corresponding to what is drawn, the signals being stored in a high resolution store (25). While the processing of the signals progresses certain signals are copied to a lower resolution viewing store (26) and these signals read to a display (27) where the image can be viewed by the operator. In one example the store (25) is notionally divided into areas and when the signals representing a stroke drawn by the operator are present in an area the whole area is copied to the viewing store. Typically about four areas need to be copied in a frame period so the stroke drawn by the operator can be seen as he is drawing it. The image on display (27) may be a low resolution version of the whole image or a high resolution version of part of the image.

Abstract: A graphic system for producing printed images. The signals representing the image are produced as CMY (cyan, magenta, yellow) printing color component signals and transformed to RGB (red, green, blue) signals for display on a monitor. The transformation circuit is a matrix of arithmetic circuits including look-up tables. The system can also be conditioned so that RGB signals are first produced and these transformed to CMY.

Abstract: This invention is concerned with systems that create video images. Previously these systems have been limited to ones which create images of television type resolution, however, the systems of this invention may produce an image of higher resolution. The operator draws on a touch tablet and chooses a color and implement type and a line is produced which appears on a screen in approximately real time. At the same time a corresponding line is being produced and written in at high resolution to a large frame store. The high resolution line will be produced at a slower rate than the line to be viewed and so a buffer store is provided for incoming signals. The high resolution image may be read to a print scanner or stored on a disc store.

Abstract: A video graphic simulation system which is capable of producing an image of a panorama as viewed from different positions. To save storage space lines of video signals may be repeated at the edges of the view so that for example the view from a rolling vessel may be seen. Where simple repeating of lines may produce visible discontinuities alternate strips of video signals may be `mirrored`.