Patent ID: 6990250

Claim:
An image signal processing apparatus for emphasizing a specific frequency component of an image signal and clarifying the contour of a reproduced image, comprising: a first gamma correction circuit for performing gamma correction with respect to an original image signal on the basis of first non-linear characteristic conversions; an edge signal generation circuit for generating an edge signal by extracting a specific frequency component of said original image signal; a second gamma correction circuit for performing gamma correction in accordance with second non-linear characteristic conversions with respect to a first intermediate image signal that is generated on the basis of said original image signal and said edge signal; a third gamma correction circuit for performing gamma correction in accordance with said second non-linear characteristic conversions with respect to a second intermediate image signal that is generated on the basis of said original image signal; a subtraction circuit for generating an aperture signal by calculating the difference between the gamma-corrected first intermediate image signal and the gamma-corrected second intermediate image signal; and an addition circuit for generating an output image signal by adding said aperture signal to the gamma-corrected original image signal.