Patent ID: 7633529

Claim:
A method for switching between chromatic and monochromatic modes in accordance with a brightness of an object being imaged, the method comprising: (a) determining whether a present mode is a chromatic mode or a monochromatic mode; (b) if the present mode is the monochromatic mode, determining whether a minimum illumination, which controls time for receiving an image signal from an object, is set; (c) if the minimum illumination is set, calculating a minimum illumination value; (d) determining whether the calculated minimum illumination is below a minimum illumination threshold; (e) if the calculated minimum illumination value is below the minimum illumination threshold, switching from the monochromatic mode to the chromatic mode; (f) if the minimum illumination is not set in the step (b), calculating an AGC (Auto Gain Control) gain which increments and decrements a brightness value of an image signal; (g) determining whether the calculated AGC gain is below an AGC gain threshold; and (h) if the calculated AGC gain is below the AGC gain threshold, switching to the chromatic mode.