CIE 118-1995

This volume contains short Technical Reports, Research Notes and Reporters' Reports prepared by various Technical Committees and Reporters within Division 1. In part they were published in the "CIE Journal" in 1986.

118/1 Evaluation of the attribute of appearance called gloss This Research Note was originally published in CIE-Journal, Vol.5, No.2, 41-56, 1986.

This technical report discusses current concept of gloss as an appearance phenomenon and as a measured attribute of materials. First the general attributes of appearance are described, followed by a description of gloss attributes. The interaction of light and materials that is responsible for gloss sensations is briefly covered. Definitions are given for terms related to gloss perception and to the light-reflection properties of materials associated with gloss. The general design characteristics of specular glossmeters are described and standard procedures for gloss measurement are tabulated according to gloss-scale geometry and according to country of usage. Material standards for specular-gloss scale calibration are discussed.

118/2 Models of heterochromatic brightness matching This Research Note was originally published in CIE-Journal, Vol.5, No.2, 57-59, 1986.

The report describes a method to compare the brightness of two stimuli seen foveally at photopic luminance levels as unrelated colours. The report, based on the research of Cowan and Ware, was published as an interim method.

118/3 Brightness-luminance relations

The Reporter's Report covers the period 1993-1994 and summarises results from 13 (partly older) papers.

This report was prepared by F.J.J. Blommaert, Netherlands

118/4 CIE Guidelines for co-ordinated research on evaluation of colour appearance models for reflection print and self-luminous display image comparisons This Communication was published in Colour Research & Applications 19/I, 48-58, 1994.

The goal of CIE TC 1-27, Specification of Colour Appearance for Reflective Media and Self-Luminous Display Comparisons, is to gather as much data from as many different sources as possible for the evaluation of colorimetric and colour appearance models used to create visual matches for self-luminous display (softcopy) and reflection print (hardcopy) image comparisons. Visual results will be compared to predicted results expressed in terms of standard colorimetric CIELAB and CIELUV equations, modifications of CIELAB and CIELUV equations, and the more current colour appearance models proposed by Dr. Robert W. G. Hunt and Dr. Yoshinobu Nayatani and coworkers. We hope to determine which approach, i.e. a standard colorimetric one, a modified colorimetric one or a colour appearance one, is the best for predicting perceptual results of image comparisons between hardcopy reflective and softcopy self-luminous media.

A similar effort was undertaken by Dr. Alan Robertson in the area of Colour-Difference Evaluation. Dr. Robertson's efforts were successful in that many different data sets were generated and people began thinking about colour-difference evaluation in new ways. Our Technical Committee efforts will be viewed as successful if a variety of data sets are received allowing us to evaluate results with traditional and non-traditional colour science models. These guidelines will outline experimental set-up procedures, psychophysical experimental methods for the visual assessments, colour measurement procedures, data analysis and colour specification requirements for the evaluation of a common image produced on a self-luminous display and a reflection print. The experimental design defines the reflection print image as the reference colour original and the self-luminous display image must be designed to visually match that reflection print original.

These guidelines have been developed in the hopes that other colour scientists, particularly those working in the area of hardcopy (reflection prints) and softcopy (self-luminous displays) matching can conduct coordinated research according to any of the prescribed techniques to generate data that may serve as input to the CIE TC 1-27 evaluation of various colour science models for these applications.

118/5 Testing colour appearance models: Guidelines for co-ordinated research (to be also published in Color Res. & Appl.)

These guidelines provide an overview of the many issues involved in generating visual data that can be used to evaluate the performance of colour-apperance models. The three main sections of these guidelines outline the parameters that must be evaluated and controlled in experimental setups for colour-appearance experiments, suggested psychophysical techniques for gathering the data, and some suggested techniques for data analysis. Experimental parameters addressed include models to be tested, illumination conditions, background and surround conditions, types of stimuli to be used, and issues relating to viewing technique. The psychophysical techniques of magnitude estimation, matching, and direct model testing (paired comparison) are described. Data analysis techniques for the evaluation of colour-appearance scales, corresponding-colours data, and model performance scales are suggested.

118/6 Report on color difference literature

This Reporter's Report covers the period 1991-1992 and summarises results from 14 papers published.

This report was prepared by T Maier,USA

118/7 CIE Guidelines for co-ordinated future work on industrial colour-difference evaluation (to be also published in Color Res. & Appl.)

Recent results of research work on colour-difference evaluation are reviewed in reports of two CIE Technical Committees, however, a global solution of the problem is still lacking. Therefore, guidelines for planning new research work are included in those reports. Here, these guidelines are explained and extended to stimulate new studies in a co-ordinated way which could improve modelling of colour-difference evaluation for industrial application.

This report was prepared by K. Witt, Germany

The publication contains also abstracts of 20 CIE Publications dealing with colour and vision. The Technical Collection is written in English, with short summaries in French and German. It consists of 65 pages.