An edge enhancement circuit uses bandpass filters to separate an original
video signal into low-, middle- and high-frequency band edge components
which will be supplied to waveform shaping circuits. Each of the waveform
shaping circuits detects an amplitude peak level of the edge component,
generates a gain coefficient based on the peak level, and multiplies the
original video signal by the gain coefficient. The results of
multiplication are added together to generate a final detail signal.
Thus, the edge enhancement circuit amplifies the amplitude of the edge
component having a frequency approximate to the spatial frequency of the
video signal to provide an edge enhancement based on a frequency
characteristic corresponding to the spatial frequency of the video
signal.