Table 1.
Conditions employed by Sakano and Ando (2010).
Figure 1.
Relationship between the viewpoints (camera positions), the stimulus, and the light sources.
The stimulus was illuminated by three fixed point-source lights. The distance between the stimulus and the camera positions was 57 cm, the same as the distance between the monitor and participant.
Figure 2.
The stimuli were computer-generated spherical achromatic objects that were glossy and bumpy. They were modeled and rendered using POV-Ray (ver. 3.6.2). Stimuli for seven specular reflectance levels are shown: 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60. The diffuse reflectance was set so that the mean luminance of all stimuli was equal.
Figure 3.
Flowchart of the experimental procedure.
The time sequence of one session is shown. The first three frames were presented once and then those from the blank to the response were repeated 28 times. Further details are given in the text.
Figure 4.
Perceived glossiness as a function of specular level for the four conditions.
A. The solid lines show the results of the linear regression of the data in the Dimage-Dobserver, Dimage-Sobserver, Simage-Dobserver, and Simage-Sobserver conditions. The data are well fitted in all conditions. The glossiness of the standard condition [specular level 0.45 in Fig. 2.] was defined to be exactly 1.0. B. The values of the y-intercept of each regression line. The dashed lines represent the average value, and the length of each bar represents the standard error of the mean.
Figure 5.
Comparison of the results for each condition.
The perceived glossiness ratios of the Dimage-Dobserver, Dimage-Sobserver, and Simage-Dobserver conditions to the Simage-Sobserver condition for specular levels between 0.30 and 0.60 and for all specular levels. The error bars represent the standard error of the mean. The asterisks indicate the existence of a significant difference [*: p<0.05, **: p<0.01; ***: p<0.001].