A method for quantifying a wear level of a bristle field of a brush 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 following steps: - 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; - applying at least one of the following evaluation methods: (a) determining the geometrical splay of the bristle field by creating a contour image from the binarized image with the contour pixels of the bristle field and using the coordinates of the contour pixels to determine the maximum brush width and length of the bristle field and/or by creating a convex hull enwrapping all contour pixels and having the smallest possible size to determine the area and the circumference of the bristle field; (b) determining the filament surface of all visible bristles in the image by counting the pixels in the binarized image having the one tone value of the binarized image assigned to bristles and/or bristle tufts; (c) determining the bristle tuft integrity in the image by counting separable tufts in the gray scale image by identifying local gray value maxima in the gray scale image, optionally after separating the bristle tufts by substracting a binarized image mask generated by the conversion of the gray scale image to the at least one binarized image identifying the bristle tufts. - comparing the results of the at least one applied evaluation method with reference data of an unused brush and/or of used brushes with determined wear levels to classify the wear level of the bristle field. - 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; - applying at least one of the following evaluation methods: (a) determining the geometrical splay of the bristle field by creating a contour image from the binarized image with the contour pixels of the bristle field and using the coordinates of the contour pixels to determine the maximum brush width and length of the bristle field and/or by creating a convex hull enwrapping all contour pixels and having the smallest possible size to determine the area and the circumference of the bristle field; (b) determining the filament surface of all visible bristles in the image by counting the pixels in the binarized image having the one tone value of the binarized image assigned to bristles and/or bristle tufts; (c) determining the bristle tuft integrity in the image by counting separable tufts in the gray scale image by identifying local gray value maxima in the gray scale image, optionally after separating the bristle tufts by substracting a binarized image mask generated by the conversion of the gray scale image to the at least one binarized image identifying the bristle tufts. (a) determining the geometrical splay of the bristle field by creating a contour image from the binarized image with the contour pixels of the bristle field and using the coordinates of the contour pixels to determine the maximum brush width and length of the bristle field and/or by creating a convex hull enwrapping all contour pixels and having the smallest possible size to determine the area and the circumference of the bristle field; (b) determining the filament surface of all visible bristles in the image by counting the pixels in the binarized image having the one tone value of the binarized image assigned to bristles and/or bristle tufts; (c) determining the bristle tuft integrity in the image by counting separable tufts in the gray scale image by identifying local gray value maxima in the gray scale image, optionally after separating the bristle tufts by substracting a binarized image mask generated by the conversion of the gray scale image to the at least one binarized image identifying the bristle tufts. - comparing the results of the at least one applied evaluation method with reference data of an unused brush and/or of used brushes with determined wear levels to classify the wear level of the bristle field.