Methodology for constructing a colour-difference acceptability scale

Baptiste Laborie (1, 2) , Françoise Viénot (1) , Sabine Langlois (2)

1 CRCC - Centre de Recherche pour la Conservation des Collections
2 Technocentre Renault [Guyancourt]

Observers were invited to report their degree of satisfaction on a 6-point semantic scale with respect to the conformity of a test colour with a white reference colour, simultaneously presented on a PDP display. Eight test patches were chosen along each of +a*, -a*, +b*, -b* axes of the CIELAB chromaticity plane, at Y=80 +/- 2 cd.m-². Experimental conditions reliably represented the automotive environment (patch size, angular distance between patches) and observers could move their head and eyes freely. We have compared several methods of category scaling, the Torgerson-DMT (Torgerson, 1958) method, two versions of the regression method (Bonnet's (Bonnet, 1986) and logistic regression) and the medians method. We describe in detail a case where all methods yield substantial but slightly different results. The solution proposed by the regression method which works with incomplete matrix and yields results directly on a colorimetric scale is probably the most useful in this industrial context. Finally we summarize the implementation of the logistic regression method over four hues and for one experimental condition.

Mots clés: Acceptability; colour-difference; category scaling; plasma display panel

Domaines: Optique [physics.optics]

Baptiste Laborie, Françoise Viénot, Sabine Langlois. Methodology for constructing a colour-difference acceptability scale. Journal of Ophthalmic and Physiological Optics, 2010, 30 (5), pp.568-577. ⟨10.1111/j.1475-1313.2010.00765.x⟩. ⟨hal-00588648⟩