METHOD OF AUTOMATIC FOCUSING OF CAMERA IN A CCTV

摘要

PURPOSE: An AF control method of a CCTV camera is provided to automatically control focus according to a focus distance. CONSTITUTION: If screen data transferred to a controller through a DSP(Digital Signal Processor) reaches 1 field, the controller stores a value stored in a new focus data field to an old focus data field and stores the subject edge data of the 1 field to an empty new focus data field(S502). The controller compares the size of focus data stored in the two fields and determines whether the focus data increases(S503). In case data corresponding to focus decreases in data extracted from the edge data of a present subject, the controller determines that focus data decreases(S504).