Abstract: In the case of a method for sensing a marking (2) of a running web of material (3), the web of material is optically scanned by an image recording device (6). This generates in successive measuring cycles image signals which are fed to an image processing device (7). This image processing device (7) determines the positional values of the marking (2) of the web of material (3). A validity signal is generated from these positional values by applying a position-dependent weighting function and is output. This validity signal indicates whether the currently determined positional value is valid.

Abstract: In the case of a method for sensing a marking (2) of a running web of material (3), the web of material is optically scanned by an image recording device (6). This generates in successive measuring cycles image signals which are fed to an image processing device (7). This image processing device (7) determines the positional values of the marking (2) of the web of material (3). A validity signal is generated from these positional values by applying a position-dependent weighting function and is output. This validity signal indicates whether the currently determined positional value is valid.

Abstract: The travel of a fabric web is corrected by an image acquisition from a region thereof including a guidance criterium which can be interrupted to produce a single row of image points, the signals of which are digitalized and compared with a reference signal by relative shifting of the stored signals in two shift registers. The number of shifts required to bring about correlation is determined as a measure of the actual position of the web and compared to a setpoint position for operation of an effector restoring the web to its set point position.