Patent ID: 8050513

Claim:
A method of enhancing the contrast of an image that is represented by a digital signal, comprising: a computer creating at least one approximation image at one or multiple scales, an approximation image at a scale representing the grey values of said image in which all details at that scale have been omitted; the computer creating translation difference images by pixel-wise subtracting the values of an approximation image at scale s and the values of a translated version of said approximation image; the computer non-linearly modifying the values of said translation difference image; the computer computing at least one enhanced center difference image at a specific scale by combining said modified translation difference images at that scale or a smaller scale with weights w i,j in which said weights w i,j are selected such that, if no enhancement is performed, an equivalent of a multi-scale decomposition of said image is obtained; and the computer computing an enhanced image by applying a reconstruction algorithm to the enhanced center difference images.