Yuri Ostrovsky

Face Recognition by Humans: Nineteen Results All Computer Vision Researchers Should Know About

A key goal of computer vision researchers is to create automated face recognition systems that can equal, and eventually surpass, human performance. To this end, it is imperative that computational researchers know of the key findings from experimental studies of face recognition by humans. These findings provide insights into the nature of cues that the human visual system relies upon for achieving its impressive performance and serve as the building blocks for efforts to artificially emulate these abilities. In this paper, we present what we believe are 19 basic results, with implications for the design of computational systems. Each result is described briefly and appropriate pointers are provided to permit an in-depth study of any particular result

Perceiving Illumination Inconsistencies in Scenes

The human visual system is adept at detecting and encoding statistical regularities in its spatiotemporal environment. Here, we report an unexpected failure of this ability in the context of perceiving inconsistencies in illumination distributions across a scene. Prior work with arrays of objects all having uniform reflectance has shown that one inconsistently illuminated target can ‘pop out’ among a field of consistently illuminated objects (eg Enns and Rensink, 1990 Science 247 721–723; Sun and Perona, 1997 Perception 26 519–529). In these studies, the luminance pattern of the odd target could be interpreted as arising from either an inconsistent illumination or inconsistent pigmentation of the target. Either cue might explain the rapid detection. In contrast, we find that once the geometrical regularity of the previous displays is removed, the visual system is remarkably insensitive to illumination inconsistencies, both in experimental stimuli and in altered images of real scenes. Whether the target is interpreted as oddly illuminated or oddly pigmented, it is very difficult to find if the only cue is deviation from the regularity of illumination or reflectance. Our results allow us to draw inferences about how the visual system encodes illumination distributions across scenes. Specifically, they suggest that the visual system does not verify the global consistency of locally derived estimates of illumination direction.

Vision Following Extended Congenital Blindness

Animal studies suggest that early visual deprivation can cause permanent functional blindness. However, few human data on this issue exist. Given enough time for recovery, can a person gain visual skills after several years of congenital blindness? In India, we recently had an unusual opportunity to work with an individual whose case history sheds light on this question. S.R.D. was born blind, and remained so until age 12. She then underwent surgery for the removal of dense congenital cataracts. We evaluated her performance on an extensive battery of visual tasks 20 years after surgery. We found that although S.R.D.s acuity is compromised, she is proficient on mid- and high-level visual tasks. These results suggest that the human brain retains an impressive capacity for visual learning well into late childhood. They have implications for current conceptions of cortical plasticity and provide an argument for treating congenital blindness even in older children.

Vision after 53 years of blindness

Several studies have shown that visual recovery after blindness that occurs early in life is never complete. The current study investigated whether an extremely long period of blindness might also cause a permanent impairment of visual performance, even in a case of adult-onset blindness. We examined KP, a 71-year-old man who underwent a successful sight-restoring operation after 53 years of blindness. A set of psychophysical tests designed to assess KPs face perception, object recognition, and visual space perception abilities were conducted six months and eight months after the surgery. The results demonstrate that regardless of a lengthy period of normal vision and rich pre-accident perceptual experience, KP did not fully integrate this experience, and his visual performance remained greatly compromised. This was particularly evident when the tasks targeted finer levels of perceptual processing. In addition to the decreased robustness of his memory representations, which was hypothesized as the main factor determining visual impairment, other factors that may have affected KPs performance were considered, including compromised visual functions, problems with perceptual organization, deficits in the simultaneous processing of visual information, and reduced cognitive abilities.

Haptic-visual transfer in children with treatable congenital blindness

The Smart Pulse tecnology use a gemetrical model based on a fullerene structure other, importante instrument of security is the integrated contact free optical pachymetry that provides precision information about the thicness ofthe córnea throughout the entire duration of the treatment. The 7D eye impresses a apart from the linear movements (1st and 2and dimentions). Compensations of the eye rotation around its optical axis.

Haptic-Visual Transfer in Children with Treatable Congenital Blindness

The Smart Pulse tecnology use a gemetrical model based on a fullerene structure other, importante instrument of security is the integrated contact free optical pachymetry that provides precision information about the thicness ofthe córnea throughout the entire duration of the treatment. The 7D eye impresses a apart from the linear movements (1st and 2and dimentions). Compensations of the eye rotation around its optical axis.