1. A method of enhancing the contrast of a detail image that is represented by a digital signal, the method comprising: at least one approximation image is created at one or multiple scales, an approximation image at a scale representing the grey values of said detail image in which all details at that scale have been omitted, translation difference images are created by pixel-wise subtracting the values of an approximation image at a scale and the values of a translated version of said approximation image, a non-linear modification is applied to the values of said translation difference images to generate modified translation difference images, at least one enhanced center difference image at a specific scale is computed by combining said modified translation difference images at that scale or a smaller scale with weights, said weights being selected in accordance with an image decomposition algorithm such that, if the enhancement by non-linear modification is not performed, an equivalent of the multi-scale decomposition of said image would be obtained in which the at least one center difference image would be equal to the detail image at the specific scale, an enhanced image is computed by applying a reconstruction algorithm to the enhanced center difference image, wherein at least one of the following actions is performed: (1) said non-linear modification of the values of said translation difference images is steered by a characteristic computed out of said approximation image at at least one scale, (2) said approximation image at a scale is filtered to generate a filtered approximation image, (3) said enhanced center difference image is filtered.