Technique for backlight compensation by selecting most appropriate compensation area and controlling iris in accordance with luminance level thereof

摘要

A technique for backlight compensation in a monitoring camera performs automatic backlight compensation without any need for manually redesignating a backlight compensation area, despite changes in ambient illumination, by selecting the most appropriate backlight compensation area for changes in the ambient illumination and the movement of an object from among a plurality of predetermined backlight compensation areas and controlling an iris on the basis of the luminance signal level of the selected backlight compensation area, to thereby control the luminance signal level. A backlight compensation is performed by adjusting the positions and sizes of backlight compensation areas so as to be suitable to the surroundings of the monitoring camera by a user, and automatically or manually selecting the most appropriate backlight compensation area in accordance with changes in illumination and changes in the position of the object, and controlling the iris according to the luminance signal level of the selected backlight compensation area.