An image forming apparatus, comprises: a setting unit configured to set a divider region in a group of images that are continuously printed during feeding from a feeding apparatus in which a roll-shaped printing medium has been set, the divider region being for separating the roll-shaped printing medium into a plurality of rolls. The setting unit sets the divider region based on the number of rolls indicating the count of the plurality of rolls, the number of rolls being required in terms of a configuration of a post-processing device that executes post-processing with respect to the roll-shaped printing medium on which printing has been performed by the printing unit.

The present invention relates to systems and methods for calculating the additional local stretching of a moving web through a converting process in order, during rewinding, to find the position of defects in the web that were identified during winding and stopping the web with the web defect close to or at a defect correcting station. The method comprises, during rewinding of the web, the steps of detecting position markers (PM(n)) applied during winding of the web (5), measuring the distance between the position markers, calculating the additional local stretching between the position markers occurring during rewinding, applying the calculated additional local stretching to the known position of a following web defect to determine an estimated position of that web defect in the rewinding web. A method for correcting a web defect comprises the step of subsequently stopping the web with the web defect at, or close to, a defect repairing station (38).

A method for computer-implemented tracking of production history of a continuous web is provided, which is-processed in a production system, including a sub-system applied to perform specific operation(s). The web is transported along a curved given path through the production system by winding/unwinding from/onto a coil. The following are performed: obtaining measured data of the web while being transported along the path, the measured data being current time-stamped measured data acquired a sensor or a measuring device installed at the production system along the path, where a spatial position of each sensor and measuring device with respect to the given path determined by a one-time reference calibration; obtaining movement information of the web; determining production-relevant features of the web by processing the time-stamped measured data and the movement information of the web by mapping the time-stamped measured data to physical points of regions of the web.