Abstract: A method and device for quantifying a wear level of a bristle field of a brush are disclosed comprising a plurality of bristle tufts grouping each a plurality of single bristles, said bristle tufts being distributed over the bristle field, the method comprising the steps of recording and storing an image of the bristle field; converting the image into a gray scale image by use of digital image processing and storing the gray scale image; converting the gray scale image to at least one binarized image with only two tone values by use of digital image processing, thereby assigning one tone value to bristles and/or bristle tufts visible in the image and the other tone value to the background in the image not showing bristles or bristle tufts, and storing the binarized image.