A method and system for a printing device is disclosed. The method and system
comprise
printing a test pattern on a print medium and generating a digital image of the
printed test pattern by an imaging device. The method and system include analyzing
an interference pattern to measure for distortion of the print medium and calibrating
the printing device based upon the measured distortion.
In a preferred embodiment, the present invention utilizes the reticle patterns,
which are printed in the margins of the paper, which are measured real-time during
printing. The interference or Moir patterns created by superimposed reticles
may be used to measure image distortion, process direction misalignment, and misregistration
caused by web distortion. The advantage of this invention is that image distortion
compensation, RIP (Raster Image Processor) parameters, timing, or other printer
characteristics may be adjusted on-the-fly in a closed feedback system, for high-speed
textile or paper color printing, utilizing on-the-fly distortion or stretch measurement
for accurate color and/or duplex images registration. In a duplex printer, automatic
images alignment front-to-back is obtained by combining optically or logically
the two images for the evaluation of interference patterns and amount of distortion
in the process and scan direction.