Visual Discomfort from Camera Panning in 4K-UHD Contents

In this paper, we analyze the visual discomfort caused by camera panning in 4K UHD contents. UHD is expected to provide a sense of realness to viewers, with four times more pixels than HD. However, UHD may yield undesirable artifacts, such as the stroboscopic effect from displaying frequency and visual fatigue due to moving objects. To investigate the visual discomfort in the presence of camera panning, subjective evaluation is conducted using video clips that are created considering the distance between the camera, characters and background. Subjective scores illustrate that the effect of camera panning is strongly correlated with the camera panning speed, and weakly related to the distance among three elements. From the subjective test, we conclude that visual discomfort occurs when the object moves at a speed over 2560 pixels per second, or 43 pixels per frame in 4K UHD contents, and 96 cm per second, or 1.6 cm per frame in a 65 inch monitor. Keywords; visual discomfortness, 4k-UHD, sense of realness, camera panning