1. A method of transforming pixels of a first digital image into pixels of a second digital image, each pixel having a value that indicates a color of the pixel, the method comprising the steps of: defining a neighborhood of pixels for a pixel of the first digital image; determining a new value for the pixel based on the values of the pixels in the neighborhood; and placing the new value of the pixel in the second digital image, wherein the step of determining a new value comprises the further steps of: determining a value of a whitest pixel in the neighborhood that indicates a color of a pixel in the neighborhood that is most close to a white color; determining a contrast between the pixel and the whitest pixel in the neighborhood; and calculating a new value for the pixel, enlarging the contrast between the pixel and the whitest pixel in the neighborhood, based on the value of the pixel in the first digital image, based on a distance between the color of the whitest pixel in the neighborhood and the white color an based on the contrast between the pixel and the whitest pixel in the neighborhood.