| 摘要 |
Without using a photodetector and only by using a simple signal processing, it is possible to detect with a high accuracy a fluorescent flicker inherent to an image pickup element of XY address scan type such as a CMOS image pickup element regardless of the object, the video signal level, and the fluorescent lamp type and reduce it reliably and sufficiently. A signal In' (x, y) is an RGB elementary color signal including a flicker component or a luminance signal. The signal In' (x, y) is integrated over a time exceeding one horizontal cycle and a difference value of integrated values in adjacent fields is normalized by an average value of the integrated values in the continuous three fields. The difference value gn (y) after the normalization is subjected to discrete Fourier transform to extract a spectrum. From the extracted spectrum, a flicker coefficient Gamman(y) is estimated to perform calculation of In' (x, y)/[1 + Gamman(y)].
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