Date of Award

Fall 2013

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Electrical and Computer Engineering

First Advisor

Jan P. Allebach

Committee Chair

Jan P. Allebach

Committee Member 1

Michael D. Zoltowski

Committee Member 2

Mireille Boutin

Committee Member 3

Zygmunt Pizlo

Abstract

Banding is a well-known artifact produced by printing systems. It usually appears as lines perpendicular to the process direction of the print. Therefore, banding is an important print quality issue which has been analyzed and assessed by many researchers. However, little literature has focused on the study of the masking effect of content for this kind of print quality issue. Compared with other image and print quality research, our work is focused on the print quality of typical documents printed on a digital commercial printing press. In this paper, we propose a Masking Mediated Print Defect Visibility Predictor (MMPDVP) to predict the visibility of defects in the presence of customer content. The parameters of the algorithm are trained from ground-truth images that have been marked by subjects. The MMPDVP could help the press operator decide whether the print quality is acceptable for specific customer requirements. Ultimately, this model can be used to optimize the print-shop work-flow.

Laser Electro-Photographic (EP) printers are complex systems that can generate prints with a number of possible artifacts that are very different in nature. It is a challenging task to develop a single processing algorithm that can effectively identify such a wide range of print quality defects. In this paper, we describe an image processing and analysis pipeline that can effectively assess the presence of a wide range of artifacts, as a general approach. In our paper, we will discuss in detail the algorithm that comprises the image processing and analysis pipeline, and will illustrate the efficacy of the pipeline with a number of examples.

Ghosting is a common print defect in Laser Electro-Photographic (EP) printing, which refers to a residual image repeat of previously printed content along the paper process direction, and appear as light or dark region relative to the surrounding field. Ghosting frequently shows in a mid-tone region following an area of solid ll. It is important to detect the location and contrast of ghosting to provide the necessary information about the ghosting source and severity. In this work, we present an algorithm for detecting and evaluating the ghosting defect. We start with a test patch design to emphasize the ghosting defect to facilitate further image processing and analysis. Moving matched filter is used to detect the ghost location along the scanned test page. The maximum Delta E as the result from the moving matched filter is used to locate and evaluate the ghosting.

Download

Share

COinS