Moiré Analysis for Assessment of Line Registration Quality

v b W r r v c t i r f i s m m l t d a n l M a bstract. This paper introduces objective macro and micro line egistration quality metrics based on Moiré interference patterns enerated by superposing a lenticular lens grating over a hardcopy est page consisting of high-frequency Ronchi rulings. Metrics for acro and micro line registration are defined and a measurement rocedure is described to enhance the robustness of the metric omputation over reasonable variations in the measurement proess. The method analyzes low frequency interference patterns, hich can be scanned at low resolutions. Experimental measureents on several printers are presented to demonstrate a comparaive quality analysis. The metrics demonstrate robustness to small hanges in the lenticular lens and grating superposition angle. For uperposition angles varying between 2° and 5°, the coefficients of ariance for the two metrics are less than 5%, which is small enough or delineating between test patterns of different print quality. 2007 Society for Imaging Science and Technology. DOI: 10.2352/J.ImagingSci.Technol. 2007 51:4 310