Abstract
When looking at a picture from the center of projection (CoP), the image on the retina is identical to the retinal image produced by the original scene. But pictures are usually not viewed from the CoP, so the retinal image differs from what would have occurred when viewing the original scene. Nonetheless, pictures seen from the wrong place continue to look largely veridical. Vishwanath et al. (2005) showed that the visual system compensates for off-to-the-side viewing by estimating the orientation of the picture surface at each point of interest (based on binocular disparity and frame perspective) and uses this estimate to in effect adjust the dimensions of the retinal image. Interestingly, when the eye is actually at the CoP, this compensation mechanism creates visible distortions in eccentric regions of the picture; the distortions are most obvious in pictures with large fields of view. We examined whether these wide-angle distortions can be reduced by (1) curving the projection plane used to create images, and (2) curving the display screen. Curving the projection plane decreases its slant from the CoP thereby reducing the stretching of the image of a depicted object, which should reduce perceived distortion. By curving the screen, the local slant of the display surface is minimized, which should also reduce distortion. We tested these predictions by measuring perceptual distortions on flat and curved (curvature radius = 418 cm) screens from 30 different viewing angles ranging from 0-50ยบ and 6 viewing distances. We found that the local slant of the display surface was the sole predictor of perceptual distortions: i.e., distortions were reduced when pictures were presented on the curved screen. We derive a set of software and hardware guidelines to create natural-looking images based on focal length, projection plane curvature, and screen curvature.
Meeting abstract presented at VSS 2015