1. A system for improving the quality of a digital image comprising: a first filter to high pass filter the image data; a mean circuit, operatively connected to said first filter, to determine absolutes values of the high pass filtered image data and to determine a mean value of the absolute values; a noise level circuit, operatively connected to said mean circuit, to determine, based upon the determined mean value, the noise of the image; a first sigma filtering circuit, using the determined noise level, to sigma filter an image to produce a sigma filtered image; a first analysis circuit to process the sigma filtered image to produce an approximation part and a detail part; a second sigma filter circuit to filter the approximation part to produce a sigma filtered approximation part; a second analysis circuit to process the sigma filtered approximation part to produce a second approximation part and a second detail part; a third sigma filter circuit to sigma filter the second approximation part to produce a sigma filtered second approximation part; a first synthesizer to synthesize the sigma filtered second approximation part and the second detailed part to produce a first reconstructed image; and a second synthesizer to synthesize the first reconstructed image and the first detail part to produce a final filtered image.