motion parallax provides depth cues based on... coursehero

Therefore, while the visual system ensures that this fixated object remains stationary on the observer's retina during the translation, presumably to maintain acuity for the visual information available at this location ( Miles, 1998), the retinal image of objects nearer and farther than the fixation point move in opposite directions on the observer's retina. Specifically, during the lateral translation we study, the observer's visual system maintains fixation on a particular stationary object in the scene by moving the eyes in the direction opposite the translation. This apparent relative movement of objectively stationary objects is created by the translation of the observer and is called motion parallax. While the human visual system can employ a variety of visual cues to object depth, the percept of depth created by the relative movements of objects in the scene is especially salient for the moving observer. The visual perception of depth is an important part of successful navigation and obstacle avoidance. An empirical version of the motion/pursuit law, termed the empirical motion/pursuit ratio, which models perceived depth magnitude from these stimulus parameters, is proposed. Head-moving conditions produced even greater foreshortening due to the differences in the compensatory eye movement signal. Similar to previous results, perceived depth from motion parallax had significant foreshortening. For each motion parallax stimulus, a point of subjective equality (PSE) was estimated for the amount of binocular disparity that generates the equivalent magnitude of perceived depth from motion parallax. A stereo-viewing system provided ocular separation for stereo stimuli and monocular viewing of parallax stimuli. Observers compared perceived depth magnitude of dynamic motion parallax stimuli to static binocular disparity comparison stimuli at three different viewing distances, in both head-moving and head-stationary conditions. An important step in understanding the visual mechanisms serving the perception of depth from motion parallax is to determine the relationship between these stimulus parameters and empirically determined perceived depth magnitude. The motion/pursuit ratio represents a dynamic geometric model linking these two proximal cues to the ratio of depth to viewing distance. The perception of unambiguous scaled depth from motion parallax relies on both retinal image motion and an extra-retinal pursuit eye movement signal. 2Math Department, University of Iowa, Iowa City, IA, USA.1Department of Psychology, Center for Visual and Cognitive Neuroscience, North Dakota State University, Fargo, ND, USA.Mark Nawrot 1 *, Michael Ratzlaff 1, Zachary Leonard 1 and Keith Stroyan 2

Motion parallax provides depth cues based on... coursehero