The Influence Of Luminance Contrast Of Signs On Pedestrians’ Gaze Behavior In Virtual Lighting Environment

The scale of metro stations keeps expanding as passenger flow growing rapidly,it is necessary to enhance the wayfinding ability of pedestrians in metro stations to accelerate the speed of flow and improve the efficiency of metro transportation.At current stage,there are more and more lighting sources which cause severer glare phenomena,hindering pedestrians’ efficient perception of navigation information and making it more difficult to find their way.Previous studies have shown that lighting conditions significantly influenced one’s visual and cognitive performance as critical environmental clues.Pedestrians’ visual attention is supposed to be adjusted by luminance and its contrast rather than illuminance,this will highlight the leading role of signs in the eyes of pedestrians,and avoid the consumption of cognitive resources in irrelevant information.To research the effect of luminance contrast between signs and their surrounding objects on the gaze behavior of pedestrians,static and dynamic rendered panoramas with virtual environment were used to simulate the wayfinding process of pedestrians in metro stations.By combining virtual reality and eye tracking,an accurate transplantation of the physical lighting environment to the virtual lighting environment was implemented.The ocular data were collected in the covert measurement while participants observed the target objects naturally.By this way,we established a psychological and physiological evaluation system in multi-dimension for the process of perceiving navigation information.In the first experiment,55 participants were recruited to observe the sign posters and advertisement boards in different lighting luminance contrasts.31 participants completed the visual search tasks at static levels,the other 24 participants were at dynamic levels,30 seconds later,they were asked to pointed out the graphic or textual changes.the numbers and the durations of fixations were recorded during the observation period,and the glare ratings were inquired afterwards.In the second experiment,143 questionnaires were distributed online for subjective evaluation,then32 participants completed the tasks in different image luminance contrast between the sign posters and the advertisement boards,the procedure remained the same with the first experiment.The results showed that luminance contrast is a visual saliency feature that distinguished the target from its surrounding objects.The value of luminance contrast is negatively correlated with the fixations and fixation durations in signs.Each increase in luminance contrast caused the reduce of the mean of fixations by 0.826,while the lighting perception is significantly worse than the one without luminance contrast.When taking the effects of lighting luminance contrast and image luminance contrast both into consideration,only in small image luminance contrast,the fixations and fixation durations increased with lighting luminance contrast.On the contrary,in large image luminance contrast,the effect of lighting luminance contrast on fixation and fixation durations reduced to insignificant.The findings indicated a strategic adjustment of focal mode and global mode in visual attention.This paper work are expected to guide the design of luminous objects in public transportation space,help to the planning of lighting and also proved that the lighting simulation in virtual environment is an effective way for visual perception analysis.