Patent ID: 8913286

Claim:
An optical control method for use in print finishing, comprising: guiding a planar printed product along a conveying path past at least one optical sensor; capturing an electronic image by use of the at least one optical sensor, wherein the electronic image represents at least one region of the printed product; extracting orientation information from the electronic image using a frequency transformation of the electronic image, said orientation information reflective of an orientation of the printed product; comparing the orientation information of the printed product from the electronic image with reference orientation information based on a first correlation, wherein the reference orientation information is based on a frequency transformation of a reference image; and generating at least one signal that reflects a result of the comparison, wherein the at least one signal comprises a first signal, which initiates a special treatment of the printed product on which the electronic image is based, if a correlation value of the first correlation falls below a first threshold value, wherein a rotation angle between the controlled printed product and the reference printed product together with direction information is calculated on the basis of the orientation information and the reference orientation information, and wherein the electronic image is rotated back by the rotating angle in such a way that the printed product imaged thereon has the same orientation as the reference printed product.