FLICKER REDUCTION METHOD, IMAGE PICKUP DEVICE, AND FLICKER REDUCTION CIRCUIT

摘要

A fluorescent light flicker characteristic of an XY addressing type image pickup device such as a CMOS image pickup device is accurately detected and reliably and sufficiently reduced through a simple signal processing without using an photosensitive element regardless of the level of a video signal of a subject and the type of a fluorescent lamp. A signal In'(x,y) is an RGB primary color signal or a luminance signal, each containing a flicker component. The signal In'(x,y) is integrated over a duration of time equal to or longer than one horizontal period, and a difference value between the integrated values of adjacent fields is normalized by the average value of the integrated values of three consecutive fields. The normalized difference value gn(y) is discrete Fourier transformed to extract a spectrum thereof, and a flicker coefficient GAMMA n(y) is estimated from the extracted spectrum to calculate In'(x,y)/Ä1+ GAMMA n(y)Ü.