1. A method of operating a printer comprising: moving a print medium through the printer in a process direction, the print medium including a plurality of pages with each page including a feature corresponding to an edge of each page in the process direction; generating, with an optical sensor, image data corresponding to a first portion of the print medium; identifying a location of the feature in the image data corresponding to an edge of a first page in the print medium; and modifying a time of operation of a marking unit in the printer to form an image on a subsequent page in the plurality of pages that follows the first page in the process direction at a predetermined distance from an edge of the subsequent page in the process direction, the modification of time being made with reference to the identified location of the feature corresponding to the edge of the first page in the image data.