1. An apparatus for producing a sharpened image from an input image, comprising: edge extraction means for receiving the input image and extracting a portion of the input image at which the brightness of the input image exhibits a great variation and outputting the extracted portion as an edge region; high frequency filter means for receiving the edge region from the edge extraction means and extracting a high frequency component of the input image from the edge region; integration means for receiving the extracted high frequency component and integrating the extracted high frequency component to output a sharpness value; parameter calculation means for receiving the sharpness value from the integration means, calculating a high frequency emphasis coefficient from the sharpness value and outputting the high frequency emphasis coefficient as a sharpening parameter; and emphasis means for receiving the sharpening parameter from the parameter calculation means and sharpening the input image based on the sharpening parameter to produce the sharpened image, said emphasis means including multiplication means for multiplying an output of said high frequency filter means by the high frequency emphasis coefficient, and addition means for adding the input image to an output of said multiplication means.