9. Psycho-visual pattern recognition: Computer Vision

Object recognition is one of the most crucial and yet least understood aspects of visual perception. A simple answer to what we mean by visually recognizing an object may be, naming the object in sight. Humphreys et al. have identified several stages in visual processing that results in naming the object through recognition. However, while discussing this issue in detail, Ullman has shown that a natural association between naming and recognizing may not be all that unambiguous. This is because, an object may simultaneously belong to a number of classes like, for example, a book, my book, a comics book, Tintin in Tibet, and so on. From this example, it is clear that naming the object in sight depends upon the subjective recognition of the appropriate class as well, which in turn depends on the purpose of recognition under the given circumstances. Furthermore, even animals that cannot express themselves through language can still visually recognize objects. Humphreys et al. in their work have also acknowledged this issue of associated subjectivity in object recognition by making distinction among semantic representation, name representation, and semantic classification in their computational model that starts from a structural representation of the object. Significantly though, they have also demonstrated that a top-down intervention from semantic units to structural description units plays an important role in object naming in terms of top-down influence from higher to lower level in recognition of vision. However, in this chapter, our focus is on understanding the complex process of object recognition at the mid-level vision in terms of the several interacting components that are involved in it, especially the factors like intensity, orientation, and relative size of the region of attention.