1. A method for discriminating texture regions and flat regions in an image, the method comprising: dividing the image into blocks of pixels; dividing each block into a plurality of pixel groups arranged in a sub-sampling raster; calculating the following variance values a for each block: an overall variance σ tot for all pixels within the block, sub-variances σ A , σ B , σ c , σ D ,. .. for the pixels of each pixel group, and a variance σ var of the sub-variances and the overall variance; determining a predetermined number of smallest values σ var of all blocks; generating an array of the values σ tot of the respective blocks corresponding to the determined smallest values σ var ; selecting one of the values σ tot from the array of variance values as a Global Variance Level GVL; determining a Global Value Threshold GVT based on the Global Variance Level GVL; calculating a local variance level σ loc for each pixel; and generating a map comprising homogeneous-texture discrimination data indicating texture regions and flat regions within the image from a comparison of GVT and σ loc .