Subjective effects of displacement errors in electronically processed stereo-television pictures

Several aspects of the roles of object contours and of rivalry and suppression in binocular vision are considered in a TV engineering context. Three experiments, using 3D b/w stills, were conducted to explore subjective effects of irregular horizontal shifts at object contours (displacement errors), which are expected to be a typical picture impairment problem of future 3D TV multi-viewpoint systems. Performance and rating tasks on a wide range of impairment magnitudes and various picture parameters served to give a quantitative estimate of the influence of displacement errors on: (1) correctness of binocular depth perception; and (2) picture quality. Two experiments (constant vs. variable location of impairments over time) with vertical grating stimuli showed binocular depth perception to withstand levels of up to 90% misplaced contour elements in one part of the stereo pair. Quality assessments were much more critical. They depended both on the proportion of impaired pixels and on the maximum horizontal width of individual impairments. A corresponding stimulus model was found to be valid for pictures with natural content, too. Impairments were less annoying when visible by only one eye instead of both. A specific formulation is given of the influence of contrast and spatial frequency features on performance.