A method for generating an output image by reducing the size of an input image by determining for a pixel location (i,j) in the output image a corresponding areaxy in the input image, fetching the input image areaxy pixel values, calculating an output pixel value Dij for the pixel location (i,j) using a size reducing algorithm, inserting Dij in the output image and repeating the previous steps for each pixel location (i,j) in the output image. The value Di,j is obtained by adding to the lower resolution background representation A of the input image area pixel values with a value obtained by amplifying MED, representing the pixel value in the input image area that most deviates from said lower resolution background representation A, by means of a significance factor SF.