VIDEO SURVEILLANCE CAMERA REFOCUS

摘要

A method of refocusing a video surveillance camera includes performing a first focusing operation of a camera at a first time, sensing first and second temperatures of the camera at respective times, determining if change between first and second temperatures is greater than a predetermined change, sensing a level of light in field of view of the camera at the second time, determining if level of light is within a predetermined light level range, determining if a period of time between the first time and second time is greater than a predetermined period of time, and performing a focus operation if the change in temperature between first and second temperatures is greater than the predetermined temperature change, the level of light sensed at the second time is within the predetermined range, and the period of time between the first and second time is greater than a predetermined time.