PURPOSE: To perform contour correction, which is not unnaturally edged, by switching and outputting a maximum value or a minimum value while comparing the average value of an input video signal amplitude value with the input signal amplitude value.
CONSTITUTION: When a video signal is inputted to an input terminal 1, it is delayed by delay circuits 20a-20dd, signals (a)-(e) are passed through maximum value and minimum value detection circuits 30 and 40 and turned to a maximum value (f) and a minimum value (g) and a signal (h) is provided by an averaging circuit 50. A comparator 62 of a switching circuit 60 compares the amplitude value of the signal (h) and that of the signal (c), for example, and according to the signal (h), either of signals (f) and (g) to a selector 61 is selected. Namely, assuming that '1' is outputted when the (c) is larger than the signal (h) and '0' is outputted in the other case, at the selector 61, a signal (i) from the comparator 62 is defined as a control signal, a signal (j) from the selector 61 is turned to the contour corrected video signal, and the picture which is not unnaturally edged can be provided.
HAMADA MASANORI
SAGAWA KENTA
UEDA KAZUYA
YAMAUCHI HIDEAKI
