| 摘要 |
PURPOSE:To automatically eliminate a backlight state at the inside of a video camera without any cumbersome manual operation by detecting a backlight state based on a video signal obtained by a sensor, and automatically correcting backlight state. CONSTITUTION:A microcomputer 10 judges whether or not there is a need to apply backlight correction to a video signal Sp based on comparison signals Sc1, Sc2 from comparators 8, 9. That is, the presence/absence of a white peak part above 100% in the signal Sp is examined, and in case the absence is judged, the backlight correction is decided to be unnecessary, but in case of necessity judged, the black level is compared with a specified value. When the black level is higher than the specified value, the backlight correction is decided to be unnecessary, but when lower, whether proportion occupied by the white peak part is higher than a determined value or not is decided. If the proportion of the white peak part is lower than the value, the backlight correction is decided to be unnecessary, but if larger, the computer 10 decides on the necessity for backlight correction, hence a backlight detection signal S1 is outputted to a processing circuit.
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