Perception of complex line drawings

In figure segregation that may accompany figural completion, only I interpretation is dominant for some figures, whereas several different interpretations can be selected almost equally for other figures. This article addresses 2 problems in explaining this fact: (a) how to define quantitative measures for features (including gestalt principles of grouping) and (b) how to estimate the probability of each interpretation on the basis of these definitions. Quantitative definitions are given to 7 features involved in figure segregation and completion: the relative number of corners, good continuation, symmetry, curvature constancy, convexity, coincidence, and similarity. Each feature's value can be calculated from the total curvature function of the contour. The probability of each interpretation drawn by the participants is calculated by applying linear multiple regression analysis. Experimental results indicate that the proposed method can estimate human performance on a figure segregation and figural completion task fairly well.