Content-Adaptive Automatic Image Sharpening

Optimal sharpness differs from image to image, de-pending on the content. In general, human observer prefers images of artifacts sharper and those of natural-objects less sharper. We have developed a content-adaptive automatic image sharpening algorithm that relies on the length of lines extracted from the image. It is applicable to images with various regions such as those contain natural and artificial objects. The proposed algorithm is expected to be used in image processing modules of image input/output devices, e.g. digital cameras, printers, etc.