Print Quality Evaluation Research Articles

Improved Pen Alignment for Bidirectional Printing

The quality of the prints produced by an ink jet printer is highly dependent on the characteristics of the dots produced by the ink jet pens. While some literature discusses metrics for the objective evaluation of print quality, few of the efforts have combined automated quality tests with subjective assessment. The authors develop an algorithm for analyzing printed dots and study the effect of the dot characteristics on perceived print alignment. The authors establish the perceptual preferences of human observers via a set of psychophysical experiments.

The Substrate Influence On Color Measurement

The repeatable quality of color image reproduction is a growing challenge for producers of digital printing devices as well as for paper producers. The complex nature of the problem is due to the large number of factors that influence the quality. The properties of the printing substrate such as whiteness, gloss and surface roughness, the colorants and the printing procedure in different combinations together with the properties of the capturing device are all factors that make objective evaluation of print quality very difficult. It is therefore imperative to develop precise methods and routines for color measurement and characterization. In this presentation, the influence of substrate properties on the final printed result will be studied by means of a flatbed digital scanner. The presentation will describe the problems associated with the influence of substrate properties on scanner calibration and will give guidelines for the use of scanners, where largescale color management control is required. The work reported here is part of an ongoing development of a set of characterization procedures that can be applied to printing situations, consisting of a variety of different printing engines and papers.

画像処理による印刷・印字の評価技術と専用装置ＡＰＱＳ

Objective evaluation of printed matter was studied briskly early in the 1980's. At a simultaneous period, (Formerly) Kanzaki Paper Co., Ltd. ((Currently) Oji Paper Co., Ltd.) worked on the research of numerical evaluation concerned with printed matter and developed the inspection device of missing dots for photogravure printing. Afterwards we developed the inspection device of offset printed matter, sheet formation, paper dirt and deinking sheet etc. then these accumulated technology achieved the special purpose machine APQS (Automated Print Quality Evaluation System) based on our domestic image processing analysis system “Dot Analyzer DA-6000”. In this report, we introduce details until developing, outline and algorithms concerned with APQS.

Print Quality Evaluation of Silica-Based Ink Jet Paper Coatings: Sheet vs. Continuous Coaters

Various protocols for measuring the quality of color ink jet prints have been developed. An automated image analysis system has been constructed and programmed to evaluate print quality measures including color gamut, black optical density, print mottle, bleed, linewidth, raggedness, and sharpness. After defining print quality evaluations a silica-based coating was coated onto paper using the continuous coating methods of a puddle press, a rigid blade coater, and a metered size press. Using the same coating, a laboratory bench-top coating unit was used to generate single sheets of papers at equal coat weights to the continuous scale. Comparisons were made between laboratory sheets and continuously generated sheets using image analysis derived measures of print quality. The information gained is useful in deciding whether laboratory screening of various coatings formulations will be of use in projecting commercial print quality. In addition, while generating this information, the benefits of a silica gel-based coating were evident.

New Mathematical Model for the Law of Comparative Judgment

The law of comparative judgment provides a useful approach for psychophysical scaling in subjective printing quality measurement and evaluation. It links the scales, through a set of equations, to the proportion of times that one stimulus is judged greater than another in terms of perceived strengths of stimuli. The equations can be further simplified with additional assumptions on the perceptual dispersion of each stimulus and on their correlations to various forms that can be solved, via least squares method, for practical applications. However, the normal deviates can approach the value of (plus or minus) infinity. Further, because the equations for the law of comparative judgment deal with the normal deviates, solutions are generally not optimized for the proportions of choice. The method of modeling the correlation between two stimuli can also be improved to reflect the underlying mechanism of perception. To overcome these problems, we propose to directly model the discriminal dispersion variation and use a maximum likelihood model to describe the law of comparative judgment. The model describes the law of comparative judgment directly in the proportion of choice domain. Solutions are also given for actual paired comparison data. Other useful information such as the standard error of predictions can also be obtained easily based on the simplified forms of the model.

The Inter-Relationship Between Paper Structure and Print Quality in Ink Jet Printing

ABSTRACTThis article describes a print quality evaluation of laboratory designed ink jet papers prepared on a dynamic former. A comparison with various plain and coated papers serves to illustrate the potential opportunity for papermakers to exploit novel types of paper structures in the future. The article will also briefly focus on some of the fundamental issues and key paper properties which perturb print quality and govern the capillary absorption of aqueous inks.

Sensory Evaluation of Paper and Print Quality

Sensory Evaluation of Paper and Print Quality

Quantitative Evaluation of Print Quality for Optical Character Recognition Systems

Objective, mechanical, and quantitative evaluation of printed characters is discussed. Print quality can be quantified by the peak value of the print contrast signal (PCS), the average stroke width, the noise factor, and the centroid deviation. An instrument for evaluating a large number of printed characters has been constructed. This instrument consists of a scanner, a minicomputer, and its peripherals. Strains imposed on the scanned data are corrected by using the characteristics of the scanner. Two types of documents are processed by the instrument, and results of evaluation are compared with the performance of an optical character recognition (OCR) system. Experimental results clarify that the proposed evaluation method of print quality can be applied in practice. Also described are a quantitative expression of print quality for a set of input characters and the feasibility of an absolute determination of print quality.

Ein Meßautomat zur Ermittlung der Druckqualität von Schriftzeichen / An automatic measurement device for the evaluation of print quality of printed characters

Article Ein Meßautomat zur Ermittlung der Druckqualität von Schriftzeichen / An automatic measurement device for the evaluation of print quality of printed characters was published on December 1, 1976 in the journal it - Information Technology (volume 18, issue 1-6).