The horizon-ratio relation as information for relative size in pictures

Abstract

The horizon-ratio relation was found to be an effective source of information for relative size in pictures under some conditions: when the difference in image size of depicted "same real size" objects was not too great (Experiment 1), and when the horizon line was not too high or too low in the picture (Experiment 2). The latter fmding seemed to be linked to the observers' identification of the horizontal line as the horizon (and not as the edge of a finite surface). In addition, individual patterns of response were remarkably systematic even in the absence of a horizon, or any other pictorial information, (Experiment 3). It is suggested that in this case observers imposed a horizon on the picture on which to base their relative size judgments, possibly based on the observer's own eye level or on the content of the picture. It is concluded that although the horizon-ratio relation provides the same kind of information as that available in the optic arrays from real scenes, pictorial information requires the satisfaction of additional constraints in order to be fully effective.Questions concerning the perception ofspatial layout in pictures have traditionally been framed in terms of"pictorial cues" (e.g., height in the picture, relative size, interposition). Research has tended to focus on the development of sensitivity to these cues in infants and young children and, to a lesser extent, among adults from non-Western cultures (see, e.g., Benson & Yonas, 1973;Granrud, Yonas, & Opland, 1985;Ireson & McGurk, 1985;Jahoda & McGurk, 1974;Olson, 1975;Olson & Boswell, 1976; Wilcox & Teghtsoonian, 1971;Yonas & Hagen, 1973). Less attention has been paid to how adults, within our own culture, successfully perceive depicted spatial relations.New questions were raised, however, by the alternative approach to visual perception proposed by 1. 1. Gibson (1966Gibson ( , 1979. Gibson argued that perception does not require the construction of space from local and punctate cues but rather the direct detection of invariant optical structures that are informative about properties of the environment. Gibson also extended this theory to account for the perception of pictures. He claimed that there is an intrinsic structural relation between pictures and the real scenes they represent; that there are informative structures in pictures; and that these structures are of the same sort as those found in the changing optic array from a real scene (1. 1. Gibson, 1971Gibson, , 1979).Gibson's followers have been keen to maintain the case for the structural equivalence of pictures and scenes (see, e.g., the contributors to Hagen, 1980). So far, however, little has been provided by way ofexample of invariant structure in the changing optic array that might also constitute a possible pictorial "invariant." Little, that is, until SedgCorrespondence may be sent to S. Rogers, Department of Psychology, University of Wisconsin, 1202 W. Johnson St., Madison, WI 53706 (e-mail: sheenar@ macc.wisc.edu).wick (1973) identified the horizon as the basis of a s...

Weakening the robustness of perspective: Evidence for a modified theory of compensation in picture perception

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Relative size perception at a distance is best at eye level

“…With this strategy, observers do not compute horizon ratios at all but only attend to the relative HIVFs ofthe tops of objects around eye level. If observers in our experiments did use this strategy, one might wonder whether observers would use the horizon ratio if an explicit horizon were available, given that observers use the horizon ratio to judge relative size in pictures (Rogers, 1996).…”

The role of eye height in perceiving affordances and object dimensions

“…Its role in apparent-size perception has been less clear. Studies manipulating EH in pictures have produced both strong (Rogers, 1996) and weak (Bingham, 1993) effects for judgments of relative object size. Empirical manipulations of EH in real scenes have also produced ambiguous results for judgments of absolute size (Stoper, 1990;Stoper & Bautista, 1992;Wraga & Neisser, 1995).…”