Patent ID: 8351734

Claim:
A video signal circuit which performs smoothing processing and sharpening processing on an input video signal to obtain an output video signal, wherein when an edge amount input (X) of the input video signal is to be converted to an edge amount output (Y), input-output characteristics of a video signal are determined by providing a first function (Function 1) and a second function (Function 2) and by setting at least one of three factors as a variable parameter, where in a positive range of X of an X-Y plane defined by the edge amount input X and the edge amount output Y, the first function passes an origin and performs smoothing processing on condition that 0<X<Th1 and the second function passes a point (Th1, 0) on an X axis at which the threshold is set to a value of X and performs smoothing processing on condition that 0<X<Th1 and performs sharpening processing on condition that X>Th1, and the three factors are a smoothing coefficient (α1) for determining the strength of the smoothing processing, a sharpening coefficient (β1) for determining the strength of the sharpening processing, and the threshold (Th1) for determining switching between the smoothing processing and the sharpening processing.