Patent ID: 7352396

Claim:
An edge emphasizing circuit which performs edge emphasizing on each of pixels forming an image signal output from an imager, comprising: a generator for generating a first edge emphasizing signal based on said image signal; a detector for detecting a magnitude of a high-frequency component that is included in said image signal and corresponding to a spatial frequency at around a target pixel; a determiner for determining said magnitude by comparing with a first threshold value and a second threshold value being larger than said first threshold value; a gain setter which sets a minimum gain when said determiner determines that said magnitude is smaller than said first threshold value, a maximum gain when said determiner determines that said magnitude is larger than said second threshold value and a middle gain that is changeable between said minimum gain and said maximum gain according to said magnitude of said high-frequency component when said determiner determines that said magnitude exists between said first and second threshold; a producer for producing a second edge emphasizing signal by applying one of said minimum gain, maximum gain and middle gain to said first edge emphasizing signal; and an adder for adding said second edge emphasizing signal to said image signal output from said imager.