Abstract: Video processing apparatus and method, in which successive video processing operations are applied to images generate corresponding processing results in the form of images or data, for storing cached items and processing results associated with the video processing operations, and providing for deleting currently cached items to provide cache space for items to be newly cached, so that non-image processing results are retained in the cache for longer than processing results in the form of images.

Abstract: A method of data processing in which a composite data processing operation, for execution by a data processing device having a memory, is assembled by a user as a linked list of sub-operations selected from a set of possible data processing sub-operations, comprises the steps of: as a sub-operation is selected by the user for inclusion in the composite operation, loading into the memory sub-operation data defining parameters of that sub-operation including input and output interfaces of that sub-operation; and in response to an initiation of execution of a sub-operation, loading sub-operation program code into the memory for execution by the data processing device; in which the sub-operation data requires less memory space than the sub-operation program code.

Abstract: A security system comprises many cameras (C1 to C128) and a large number of alarm detectors (AD1 to AD768). A system controller (2) associates alarm detectors with cameras. Views from the cameras (C) are displayed on monitors (M11 to M21). The views are displayed in any one of carious formats and any view can, in principle, be displayed on any monitor. At least some cameras have, or each camera has, a pan-and-tilt head (PT1 to PT128). Operators can control the pan-and-tilt heads (PT1 to PT128) and respond to alarms using control panels (CP1 to CP8). An operator may thus be faced with a large number of views. Views associated with active functions of the system are provided with coloured borders (B1, B2) to assist the operator. For example, views with active alarms are provided with flashing red borders (B1). Views associated with active control of a pan-and-tilt head (PT) by an operator are provided with a coloured border (B2) (e.g. green or yellow).