1. A method for the preparation of a digital image for a subsequent pattern recognition process, and for emphasizing prominent objects in the digital image, the digital image comprising pixels and the pixels having values, the method comprising the following steps: evaluating a local standard deviation of the digital image by replacing the value of each pixel of the digital image by a standard deviation value of gray levels of the pixels in a defined neighborhood of the pixel to generate a mask image; and combining the digital image with the mask image.