Factors in Perceptual Shape Completion

Humans rely on bounding contours to segment scenes and recognize objects in our 3D world, despite the challenge of occlusions that partially block objects in the visual field. Our ability to perceptually complete these occluded contours, filling in missing fragments, plays a crucial role in object recognition. Previous research has assessed local and global methods for shape completion based on their objective accuracy, but not in relation to human perceptual completion. In this thesis, observers viewed partially erased bounding contours, simulating occlusion, and adjusted the position of a dot along a virtual line where the contour would likely continue. The missing intervals ranged from 10% to 50% of the total shape. Analysis of objective error and bias revealed that humans use more than local cues in shape completion, indicating a complex integration of information to perceptually restore missing contours.