Discomfort luminance level of head‐mounted displays depending on the adapting luminance

Abstract

The Images in an immersive head‐mounted display (HMD) for virtual reality provide the sole source for visual adaptation. Thus, significant, near‐instantaneous increases in luminance while viewing an HMD can result in visual discomfort. Therefore, the current study investigated the luminance change necessary to induce this discomfort. Based on the psychophysical experiment data collected from 10 subjects, a prediction model was derived using four complex images and one neutral image, with four to six levels of average scene luminance. Result showed that maximum area luminance has a significant correlation with the discomfort luminance level than average, median, or maximum pixel luminance. According to the prediction model, the discomfort luminance level of a head‐mounted display was represented as a positive linear function in log10 units using the previous adaptation luminance when luminance is calculated as maximum area luminance.

Prediction model for discomfort luminance levels of head‐mounted displays

“…The FoV of the full‐screen patch was approximately 100°. The definition of discomfort luminance level has been introduced based on the verbal instruction in the study by Ha et al 13 …”

“…The luminance of the test stimuli was set to 10 levels for each adaptation luminance. Ten luminance levels were selected with a similar interval in log scale, and the range of the luminance levels for each adaptation luminance was decided based on the Ha (2020) model 13 . Thus, the middle of the test stimulus was similar to the predicted discomfort luminance level based on the Ha (2020) model.…”

“…In the case of HMDs, there is no light source except the display light, and the field of view (FoV) of HMDs is generally greater than , which covers not only the fovea but also the peripheral vision. To determine the proper luminance of HMDs, Ha et al conducted a psychophysical experiment 13 . In the experiment, the luminance thresholds that cause discomfort due to excessively high brightness (i.e., discomfort luminance levels) were investigated using complex images and neutral patches under various adaptation luminance levels.…”

“…To determine the proper luminance of HMDs, Ha et al conducted a psychophysical experiment. 13 In the experiment, the luminance thresholds that cause discomfort due to excessively high brightness (i.e., discomfort luminance levels) were investigated using complex images and neutral patches under various adaptation luminance levels. Based on the results of Ha's experiment, a prediction model for the discomfort luminance level of HMDs (i.e., Ha 2020 Model) was proposed using the adaptation luminance with a power function.…”

Perceptual difference between the discomfort luminance level and the brightness of a head-mounted display (HMD)

“…the luminance threshold that causes visual discomfort to users) increases as the luminance of the previous scene increases when the viewer fully adapts to the previous scene. Thus, a discomfort luminance level prediction model for HMD was proposed as a function of the adaptation luminance based on experimental data [7]. To understand this phenomenon better, the perceptual factors that affect the discomfort luminance level need to be investigated.…”