| 摘要 |
PURPOSE:To detect not only a horizontal component but also a vertical compo nent of an edge by outputting an edge vertical component detection signal when the absolute value of the difference between a current video signal and a video signal of two horizontal scanning lines exceeds a reference value. CONSTITUTION:A subtractor 13 subtractes the video signal, which passes delay circuits 11 and 12, preceding by two lines from the input video signal to output a difference signal. The difference signal passes an absolute value circuit 14 and is compared with the reference value by a comparing circuit 15. The video signal from the delay circuit 11 is supplied to a subtractor 22 in a horizontal component detecting part 20, and an adjacent picture element signal which passes a delay circuit 21 is subtracted to output a difference signal, and this signal passes an absolute value circuit 23 and is compared with a reference value by a comparing circuit 24. This signal is processed by a pattern filter 26, and logical '1' is outputted when the difference signal between adjacent picture element signals has the same polarity for three sampling periods. An OR circuit 30 operates OR between outputs of a vertical component detecting part 10 and the horizontal component detecting part 20 to generate and output the edge detection signal.
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