摘要 |
An image sharpness calculation method and apparatus by which sharpness values of many and unspecific images having different degrees of the unsharp condition can be calculated are disclosed. In the method and apparatus, a high frequency component or a high frequency band component of a portion of an input image at which the brightness of the input image exhibits a great variation is extracted, and the thus extracted high frequency component or high frequency band component is integrated to calculate a sharpness. Also an image sharpening apparatus by which optimum sharpening of an image to achieve a high picture quality can be performed automatically is disclosed. The image sharpening apparatus comprises sharpness calculation means for calculating a sharpness of an input image, parameter calculation means for calculating a sharpening parameter based on the thus calculated sharpness, and emphasis means for emphasizing brightness of the input image based on the thus calculated sharpening parameter.
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