The Werth image processing sensor provides fully automatic measurement of complicated, extremely low contrast work pieces in transmitted and incident light illumination. True contour processing simplifies the recording of complete, enclosed contour parts. Special filtering methods for grayscale image processing, such as contour and image filters reduce the influence of different states of machining, or of dirt particles, on the measurement results. They also have functions for increasing contrast. A light controller ensures that illumination intensity is automatically adapted to changes in surfaces and colors. Measurements in the Z axis are taken by the image processing sensor by focus variation, either by surface measurements as a point cloud (3D patch) or as a single point.