To provide an enhancer circuit of a system for emphasizing a high frequency component to improve a sense of resolution of an image signal that prevents emphasis applied to even up to noise in addition to a substantial high frequency component or unexecution of sufficient high frequency emphasis on the contrary due to differences between kinds and characteristics of image signal sources when the enhancer circuit uniformly emphasis the high frequency components and uniformly applies coring processing to the image signals.

The enhancer circuit detects a noise level characteristic of the image signal for an inactive image period such as a vertical blanking period and controls the characteristic of high frequency emphasis processing on the basis of a result of the detection. Further, the enhancer circuit individually controls the characteristic of high frequency emphasis processing by each of a plurality of frequency bands. Moreover, the enhancer circuit controls the characteristic of high frequency emphasis processing by detecting the high frequency component in an effective image region by each frequency band and also discriminating whether or not the image signal includes the frequency component.

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