| 摘要 |
PURPOSE:To eliminate an inclined section attendant with the leading or trailing of a level and to obtain a binary signal correctly corresponding to a change of the level of a picture signal by dividing the picture signal into plural blocks individually carrying out the integration of the picture signal at every block and making the respective integrated value a slice level of the block. CONSTITUTION:After a picture signal VS is amplified by an amplifier 1, it is supplied to the first comparator 2. At the same time, it is guided to an integra tor 3, further digitized by an AD converter 4 to be supplied to the second compa rator 5. To other input end of the comparator 5, a predetermined reference black level signal SG is supplied, and a comparison output with the picture signal VS is stored in a memory 6 by one line. Accordingly, the picture signal in the memory 6 is delayed and outputted by one line, made analog in a DA converter 7, and thereafter inputted to the first comparator 2. If the output of an amplifier 1 is n-th line picture signal, the output of the DA converter 7 is a slice level signal corresponding to (n-1)-th line picture signal. The compa rator 2 outputs the comparison output of both the signals as a binary signal showing white or black.
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