Manufacturing imperfections of photoconductor (PC) drums in electrophotographic (EP) printers cause low- frequency artifacts that could produce objectionable non-uniformities in the final printouts. In this paper, we propose a technique to detect and quantify PC artifacts. Furthermore, we spatially model the PC drum surface for dynamic compensation of drum artifacts. After scanning printed pages of flat field areas, we apply a wavelet- based filtering technique to the scanned images to isolate the PC-related artifacts from other printing artifacts, based on the frequency, range, and direction of the PC defects. Prior knowledge of the PC circumference determines the printed area at each revolution of the drum for separate analysis. Applied to the filtered images, the expectation maximization (EM) algorithm models the PC defects as a mixture of Gaussians. We use the estimated parameters of the Gaussians to measure the severity of the defect. In addition, a 2-D polynomial fitting approach characterizes the spatial artifacts of the drum, by analyzing multiple revolutions of printed output. The experimental results show a high correlation of the modeled artifacts from different revolutions of a drum. This allows for generating a defect-compensating profile of the defective drum.

Date Published: 8 February 2015
PDF: 10 pages
Proc. SPIE 9396, Image Quality and System Performance XII, 93960H (8 February 2015); doi: 10.1117/12.2081428

Published in SPIE Proceedings Vol. 9396:
Image Quality and System Performance XII
Mohamed-Chaker Larabi; Sophie Triantaphillidou, Editor(s)