1. Image processing system ( 1 ) for contrast enhancement of an input image comprising an input module ( 2 ) for receiving the input image to be processed, a filtering module ( 4 ) operable to locally process the input image by filters of different scales (k), whereby for each of the different scales (k) a locally processed image data and at least one statistic value corresponding to the locally filtered image data is generated, a combining module ( 5 ) operable to locally combine the processed image data of the different scales (k) using a gain function (G), thereby generating a contrast enhanced image (o), wherein the gain function (G) is dependent on the at least one statistic value corresponding to the locally processed image data of the respective scale (k), and an output module ( 3 ) for outputting the contrast enhanced image characterised in that the gain function (G) comprises at least one further local dependent correction term in order to suppress artefacts in the contrast enhanced image, the local dependent correction term comprising an edge correction term (b) for attenuating the gain function (G) in areas of the input image adjacent to and/or comprising edges.