scope:

Introduction

Differences in colour vision in the periphery from that in the fovea have been known for a long time, and a number of studies on peripheral colour vision have been reported (Ferree and Rand, 1924; Committee on Colorimetry (OSA), 1953; Moreland and Cruz, 1959; Boynton et al., 1964; Moreland, 1972; Gordon and Abramov, 1977; Stabell and Stabell, 1979a; Stabell and Stabell, 1979b; Stabell and Stabell, 1979c; Uchikawa et al., 1982; Sekiguchi, 1983; Ikeda et al., 1985; Abramov et al., 1991; Takase and Uchikawa, 1991; Abramov et al., 1992; Hibino, 1992; Nagy and Doyal, 1993; Nerger et al., 1995; Takase, 1997; Segawa et al., 1999; Otake and Cicerone, 2000; Yujiri et al., 2000; Knau and Werner, 2002; Sakurai et al., 2002; Ayama and Sakurai, 2003; Sakurai et al., 2003; Ayama et al., 2004; Hamada and Yujiri, 2004; Fujisawa et al., 2004). From the point of view of practical application, the investigation of the property of colour perception over the entire visual expanse has importance for the design of control panels for automobiles, aircraft, trains, etc., layouts of signals and sign boards on roads or in public spaces, arrangement of multi-displays in control rooms, and so on.

Among the literature listed above, several studies have reported on the colour perimetry, giving a contour map of the identification (Ferree and Rand, 1924; Committee on Colorimetry (OSA), 1953) or perceived colour component of colour stimuli covering the entire visual expanse (Sekiguchi, 1983; Ikeda et al., 1985; Takase, 1997). However, the classic studies on colour identification are quite old and details of the experimental conditions and calibration procedures are not provided, making the data analysis difficult to follow. In the pioneering work of Ferree and Rand (1924), the number of observers and the chromaticities of the stimuli are not stated. In the description of contour lines for basic colours by the Optical Society of America (Committee on Colorimetry (OSA), 1953), often referred to as "colour zones" in colour vision textbooks, the definition of "colour zone" was not explicitly stated, and the experimental conditions were also not clearly stated. In this report, "colour zone" is defined as a region in the visual expanse where some function of colour vision is preserved.

Results of relatively recent studies (Sekiguchi, 1983; Ikeda et al., 1985; Takase, 1997) are not sufficient to establish reliable colour zone maps due to the small number of observers used, although experimental conditions and procedures are described in detail in these studies. In addition, as some of the literature has already revealed, the change in colour appearance with retinal eccentricity depends on the size and luminance level of the stimulus as well as the surround and adaptation condition (Stabell and Stabell, 1979a; Ikeda et al., 1985; Abramov et al., 1991; Abramov et al., 1992; Nagy and Doyal, 1993; Takase, 1997; Yujiri et al., 2000; Sakurai et al., 2002). Thus, a new reliable database of colour zones measured using an appropriate stimulus size and luminance level under an adaptation condition that is applicable to practical situations in various fields is required. For that reason, CIE Division 1 established Technical Committee 1-42 to prepare a Technical Report on colour-appearance zones for coloured lights in terms of unique hues in peripheral vision.

In conjunction with this Technical Committee, several studies were published that concerned the change in colour appearance with eccentricity, expressed by using the concept of unique hue component (Sakurai et al., 2002; Ayama and Sakurai, 2003; Sakurai et al., 2003; Ayama et al., 2004). The results showed a similar decrease in saturation and hue shifts for coloured lights in the periphery, indicating common characteristics regardless of differences in the race of the observers and detailed procedure (Ayama et al., 2004). This report describes the contour maps of redness, yellowness, greenness and blueness, covering the entire visual expanse, which show how the perceptual strength of each unique hue component in a given stimulus changes with eccentricity. Colour zone maps reported here are based on the results of a study by Sakurai et al. (2003), because their observations were carried out over the entire visual expanse.