A matrix camera with integrated LED illumination for incident lighting detects the stitch and thread density on a moving web without touching the product. A controller compares the actual value with the target value set and outputs a corresponding speed target value to the overfeed roller. Because the camera cannot be mounted after the overfeed roller for space reasons, control of the thread/stitch density is only open-loop and not regulated. After the process, there is also a further camera for checking the stitch/thread density and automatically adjusting the target value on the infeed.