Gloss: measurement, characterization and visualization - in the light of visual evaluation
2002 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]
Gloss is one essential characteristic of print quality but it is, as has long been known, a far more complex visual concept than the present methods of instrumental gloss evaluation are able to characterize.
A measurement tool, aimed to characterize the visually most important gloss features, has been developed. The tool provides a "Reflection Vector Map" (RVM) which simultaneously contains spatially resolved information about directed reflectance and apparent inclination. The RVM is comprehensive gloss information that at the same time has an intuitive interpretation.
A model to describe the perceived homogeneity of gloss has been developed. The gloss homogeneity index: "Gloss Angle Smoothness" (GAS), derived from the RVM is calculated by weighting perceptually "positive" and "negative" components of gloss homogeneity, aimed to be a predictor of how homogeneous the surface is perceived with respect to gloss. The gloss homogeneity was considered to be difficult to evaluate visually; experienced judges were in better agreement than inexperienced judges. The GAS correlated considerably better to the results of the panel of experienced judges, than did the results of a panel of inexperienced judges.
A computer visualization environment that uses the RVM as input, yielding a virtual reality for gloss evaluation of surfaces, was developed. The environment is able by simulation to mediate multiple perceptually important aspects of gloss, under well-defined and accurate observation conditions. The feature of interactivity, facilitating inspection under a range of different illumination-surface-observer-setup conditions, further adds to the sensation of high fidelity and even "presence" during inspection. Thus the environment has a potential to act as a tool during visual assessment, e.g. pair-wise comparison. Results from visual evaluations of physical and simulated demanding surfaces correlated well, with less inter-judge variance for the visualization environment than for the physical surfaces. This provides an indication of the potential both of the measurement and of the visualization systems.
Place, publisher, year, edition, pages
Linköping: Linköpings universitet , 2002. , p. 18
Series
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 975
National Category
Production Engineering, Human Work Science and Ergonomics
Identifiers
URN: urn:nbn:se:liu:diva-146006Libris ID: 8717253Local ID: LiU-TEK-LIC-2002:48ISBN: 9173734519 (print)OAI: oai:DiVA.org:liu-146006DiVA, id: diva2:1193500
Presentation
2002-11-05, Sal K3, Campus Norrköping, Norrköping, Sweden, 10:15 (Swedish)
2018-03-272018-03-272023-03-07Bibliographically approved