Video Generation Method Unconsciously Gaze-Guiding for a Passenger on Autonomous Vehicle with Controlling Color and Resolution
Authors: Miyajima Yamato , Xie Chun , Kitahara Itaru 
Published: June 2024

While automobiles are an indispensable means of transportation in our daily lives, many people suffer from motion sickness. Various symptoms such as nausea, fatigue, and vertigo develop when people become motion sickness. There are several theories on the cause of motion sickness, including the sensory confusion theory, which states that the brain becomes confused due to discrepancies in information from sensory organs such as vision, vestibular sensation, and somatosensory perception, and the eye movement theory, which states that motion sickness is caused by optokinetic nystagmus. According to these theories, gaze movements are deeply related to the cause of motion sickness. Moreover, existing research has shown that motion sickness can be alleviated by looking at a particular object. Therefore, it is considered that motion sickness can be reduced by providing gaze guidance that encourages fixation. However, explicit gaze guidance that gives visual stimuli such as flashing lights may greatly disturb the user experience while riding in a car, so it is preferable to provide unconscious gaze guidance in which the user does not feel the intention of gaze guidance. This research aims to realize unconscious gaze guidance methods to reduce motion sickness. We proposed three types of unconsciously gaze-guided video generation methods.　The first method is a resolution-controlled gaze guidance method. This method reduces the resolution by applying a smoothing process to the unguided areas and guides the gaze to the unprocessed high-resolution areas. The second method is the color-control method. This method is based on the idea that regions with high saliency in a visual saliency map are preferentially gazed at. This method guides the gaze by changing the hue and brightness of the image so that the saliency of the area to be guided becomes higher in the image. The third method is a combination of resolution-control method and color-control method. By combining these two methods, we hypothesized that we can complement the problems of both methods and achieve a stronger gaze guidance effect. We expected that unconscious gaze guidance is possible, since neither of these methods provides explicit visual stimuli. Experimental evaluations to verify the effectiveness of each method are conducted. In the experiment, we measured the gaze position while watching the generated video using an HMD with a gaze measurement function. We compared the success rate of gaze guidance between movies generated by the proposed method and movies with explicit stimuli that were shown to be effective in reducing motion sickness in existing studies. The gaze guidance rate of the movie generated with the resolution-control method was 53%, that of the movie generated with the color-control method was 34%, and that of the movie generated with the combination of the two methods was 70%. These results show that the combination of the two methods has the closest gaze guidance effect to explicit stimuli. We also conducted a questionnaire survey of the intensity with which participants felt they were being gaze guided while watching the movie. All participants felt the strongest intention of guidance with the explicit stimuli, whereas all participants felt less the intention with the proposed methods than with the explicit stimuli. Furthermore, the color-control was almost imperceptible to the intention. These findings indicate that there is a correlation between the strength of the intention of the guidance and the guidance effect. As the result, it can be considered that the guidance effect and naturalness are controlled by adjusting the degree of changes.