PURPOSE: To obtain a picture with clear contour by providing a contour section detection means, an interpolation signal generating means and a selection means and selecting an inputted picture signal or an output of the interpolation signal generating means in response to an output of the contour detection means and outputting the result to an external device.

CONSTITUTION: When a luminance signal subject to scanning line interpolation is inputted to an input terminal 101, the signal is inputted to a 1-line delay line 102 and to one input terminal of subtractors 104, 107. On the other hand, the output of the delay line 102 is inputted to one input terminal of a subtractor 105 and a delay line 103. A signal delayed by one line is outputted from the delay line 103 and the signal is inputted to one input terminal of the subtractor 105 and a selector 111. A picture signal inputted to the selector 111 is controlled to select an interpolation signal when the contour exists and to select an inputted picture signal when the contour does not exist based on a flag 110 representing the presence of the contour. Thus, a signal subject to contour emphasis in the vertical direction is outputted to an output terminal 112.