Abstract: The recognition and evaluation of locally limited colour defects in a reflective surface coating on a glass plate are carried out by digital data processing of an image delivered by a colour video camera. To this end, the coated glass plate (1) is illuminated using white light, and the light reflected by the surface coating (3) is made visible on a projection screen (6). The image appearing on the projection screen (6) is acquired by one or more colour video cameras (12, 13, 14, 15). For each of the three primary colours of the surface acquired by the colour video camera, the luminance is determined for each pixel. The relative colour fraction is determined by dividing the determined luminance values of each primary colour by the sum of the luminance values of the three primary colours at the corresponding pixels. The relative colour fractions are compared with predetermined set values.