An improved sharpening technique sharpens an image using diffusion rather than a Gaussian blur in the smearing phase. After an appropriate radius or number of passes is determined for the pixels of an image, a diffusive process is applied to the image in the smearing phase to generate a blurred image. The values of each pixel in the original image are differenced with the values of each corresponding pixel in the blurred image. The difference may be weighted by input from a user. The resulting value is added to the original image and a sharpened version of the original image is created.