Une silhouette naturelle est-elle fréquemment classée dans plusieurs catégories de base?
Ambiguous silhouettes such as the duck/rabbit (Jastrow, 1899) have been studied by several approaches. However, the figures taken as examples in the vast majority of studies are generally the same. This redundancy of the ambiguous images used in litterature implies they may be quite rare. On the other hand, anecdotal evidence suggests that they might be relatively frequent. This is what this experiment is trying to establish. We used three-dimensional models of animals from a random point of view to extract silhouettes whose perimetric complexity was subsequently modified by smoothing. Thirteen subjects were asked to indicate what they saw in the image. We show that silhouettes are classified on average with 1.9079 based categories. We also established that a decrease in the perimetric complexity initially makes a more ambiguous figure but that this effect eventually reaches a peak (at a perimetric complexity of approximately 6 times that of a disk) after which ambiguity drops.
Images ambiguës Silhouettes Illusion Ambiguous images Perimetric complexity Illusions Ambiguity