A Comparison of Visual Cue Combination Models

Abstract

Recent years have seen a proliferation of new theoretical models of visual cue combination, especially in the domain of depth perception. We simulated three models of visual cue combination: a weak fusion model, a modified weak fusion model, and a strong fusion model. Their relative strengths and weaknesses are evaluated on the basis of their performances on the tasks of judging the depth and shape of an ellipse. The models differ in the amount of interaction that they permit between the cues of stereo, motion, and vergence angle. The results suggest that the constrained nonlinear interaction of the modified weak model allows better performance than either the linear interaction of the weak model or the unconstrained nonlinear interaction of the strong model. Additional results indicate that the modified weak model’s weighting of motion and stereo cues is dependent upon the task, the viewing distance, and to a lesser degree the noise model. Although the dependencies are sensible from a computational viewpoint, they are sometimes inconsistent with experimental data. Overall, the simulation results suggest that, relative to the weak and strong models, the modified weak fusion model is a good candidate model of the combination of motion, stereo, and vergence angle cues, though the results also highlight areas in which this model needs modification or further elaboration.