Patent ID: 6953924
Filing Date: 2005-10-11
Classification: F41G,G01S,G06K

Abstract:
1. A method for extracting an illuminated zone from a matrix of photosensors of a light-detecting device, said matrix comprising a plurality of photosensors which are arranged in rows and in columns and which are each able to take one of two states, an active state when illuminated and therefore activated and a passive state when not illuminated and therefore inactivated, said illuminated zone corresponding to a set of activated photosensors the method comprising repeating the following successive steps a) to c): a) dividing a matrix field of said matrix of the light-detecting device into a plurality of search zones, which together cover said matrix field, said matrix field corresponding to the entire matrix during the first division; b) analyzing said search zones one after another in order to search for the presence of an active photosensor, the analysis of a search zone comprising using an OR logic gate connected to all the photosensors of the search zone to collect the states of all these photosensors of said search zone and to check overall if one of said states is an active state; and c) stopping the search, as soon as an active photosensor is found in a particular search zone, and employing this search zone, the size and the position on said matrix of which is known, as a new matrix field that can be reused if necessary in a new step a), wherein said repetition of steps a) to c) is continued until a matrix field comprising only active photosensors is obtained, this matrix field, the size and the position on the matrix of which are known, then corresponding to said illuminated zone to be extracted.