Visual Perception of Objects

Visual perception of objects is discussed in terms of two major topics: the perceptual organization of images into hierarchical structures of scenes (containing groups, objects, and parts) and the identification of individual objects as instances of known meaningful categories (such as chairs, houses, and dogs). The major phenomena of perceptual organization are demonstrated and discussed, including grouping, region segmentation, figure-ground perception, parsing, completion, part-whole structure, and reference frames. Several important phenomena of object identification are also demonstrated and discussed, including categorical prototypes, basic level categories, perspective effects, orientational effects, and contextual effects. Two major types of theories of object identification are outlined—part-based and view-specific theories—both of which are examined for their effectiveness in understanding how visual categorization of objects might occur. Keywords: object identification; perceptual grouping; perceptual organization; visual categorization; visual perception