The calibration of an imaging system is adjusted for geometric distortion of an image formed by a group of imaging channels on a media supported on a media support. The media support includes a plurality of individually spaced reference features disposed on a surface of the media support and a change in an expected position of at least one of the reference features is determined. Activation timing of the channels is adjusted in accordance with such changes. The imaging channels can be supported on a movable carriage and movement of the carriage can be adjusted in accordance with such changes.