US Patent 7515765 Image sharpness management

Methods, media, and a system provide image sharpness management for electronic images. Pixel values for an unmodified image are processed relative to spatial frequency bands for that image. An average pixel value is acquired for each of the spatial frequency bands and used to alter the corresponding pixel value of the image. A resulting modified image exhibits enhancement of sharpness, based on adjustments for each of the spatial frequency bands. In one embodiment, the average pixel value is adjusted based on an expected viewing distance of an observer. In another embodiment, the average pixel value is adjusted based on the ability of a display device to reproduce spatial frequencies in the image.