Patent ID: 8442340

Claim:
A non-transitory computer readable medium comprising computer executable program code adapted to enhance the contrast of an image that is represented by a digital signal by performing a method comprising: 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, 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, applying a non-linear modification to the values of said translation difference image(s), 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 , said weights W i,j , being selected such that, if no enhancement is performed, an equivalent of a multi-scale decomposition of said image is obtained, computing an enhanced image by applying a reconstruction algorithm to the enhanced center difference images, and steering said non-linear modification of the values of the translation difference images by the values of an orientation map, which comprises for each pixel on a specific scale a local direction of interest.