Patent ID: 8814305

Claim:
A method of operating an inkjet printer comprising: calibrating an optical sensor to a first white level for a blank portion of a surface of a print medium that moves over a support member, the first white level being less than a maximum white level for the optical sensor to enable the optical sensor generate image data of a transition from a first texture of the print medium to a second texture of the support member with a maximum white level generated in image data corresponding to the transition being less than the maximum white level of the sensor; generating with the optical sensor after the calibration first image data of the blank portion of the surface of the print medium and the support member; identifying a location of an edge of the print medium in the first image data with reference to the transition between a first portion of the first image data corresponding to the first texture of the print medium and a second portion of the first image data corresponding to the second texture of the support member; ejecting ink drops from a first plurality of inkjets to form a plurality of marks on the surface of the print medium in a region having a first predetermined size; generating, with the optical sensor, second image data corresponding to the surface of the print medium and the plurality of marks on the surface of the print medium; identifying with reference to the second image data a region on the surface of the print medium that is between the plurality of marks on the surface of the print medium in the region having the first predetermined size and the location of the edge of the print medium in a cross-process direction; identifying a second plurality of inkjets that are positioned to eject ink drops outside of the region having the first predetermined size and onto the print medium; and activating the second plurality of inkjets to enable the first plurality of inkjets and the second plurality of inkjets to eject ink drops during a printing operation.