1. A method of processing a digital image comprising the steps of: providing a pixellated digital image having noise components; measuring the noise components in said digital image with a noise estimation system to generate noise estimates; and sharpening said digital image with an image sharpening system which uses said noise estimates, where in said measuring step uses a noise measuring system including the following steps; generating a gradient image from said digital image; generating a histogram of gradients from said gradient image; calculating a threshold gradient from said histogram of gradients; deriving an intermediate image from said image and said gradient image; calculating an estimated image from said digital image; calculating a difference image from said digital image and said estimated image; and generating noise estimates from said difference image and said intermediate image.