Abstract: A camera for identifying soiling on a protective screen, such as a vehicle windscreen, is focused on a scene through the protective screen and can be used to identify soiling and for other applications, e.g. to identify driving lanes and/or objects in the scene. Soiling is identified merely by evaluating successively recorded image frames, and artificial reference frames or reference objects are not required. A prerequisite is that the relative speed vrel between the camera and at least one recorded object in the scene is not equal to zero and its trajectory in the image is predicted. By comparing the relevant image frame sections, possible soiling on subregions of the protective screen is identified.