A sensor head consisting of a high-resolution line scan camera (monochrome or color) with integrated line illumination is mounted on a robot arm. The robot arm executes a scanning movement on a programmed path over the surface. The path programming is easy possible by manually setting of few way points. At the beginning of the movement, the control unit of the robot arm sends a trigger signal to the camera. The camera starts the image data transfer to the computer with an adjustable delay. During the movement, the line signals are assembled one by one into a 2D image in the computer's RAM. At the end of the movement, the computer displays the image on the monitor. The image processing and evaluation can be applied to the entire image after the scan is finished, or frame-by-frame already during the scanning process.