Patent attributes
An image sharpening apparatus for sharpening an original image is disclosed. The image sharpening apparatus includes a low-pass filter, a high-pass filter, an edge detector, a sharpening parameter generating unit and an operating unit. The low-pass filter, the high-pass filter and the edge detector receive the original image and respectively output a low frequency image, a high frequency image and several edge detecting values. The sharpening parameter generating unit receives the edge detecting values and outputs corresponding sharpening parameters, respectively. The operating unit adjusts the high frequency image according to these sharpening parameters, outputs an adjusted high frequency image, and combines the adjusted high frequency image with the low frequency image to obtain an edge-sharpened output image.