Abstract
Abstract: :
Purpose:The perceived contrast of a central stimulus can be suppressed with the presence of its surround stimuli due to lateral inhibition in the visual cortex. It has been suggested that such center-surround suppression can lead to image segmentation. We performed psychophysical experiments to elucidate this relationship. Methods:We measured the effect of surrounds on the perceived contrast of a central stimulus using a contrast-matching task. The subjects matched the contrast of an isolated sine-grating patch to the perceived contrast of the same patch embeded in surrounding gratings. The matched contrast were measured at various sizes and spatial frequencies of the center-surround stimuli. Results:Our results suggested that center-surround contrast suppression was constrainted by the object boundaries, i.e, the implementation of surround suppression depended on the knowledge of object segmentation. Therefore, either the visual segmentation may occur before contrast suppression or the segmentation and contrast suppression are mutually dependent. We proposed an object-based image processing model for the the human visual system. Conclusion:Our results suggested that center-surround contrast suppression was constrainted by the object boundaries, i.e, the implementation of surround suppression depended on the knowledge of object segmentation. Therefore, either the visual segmentation may occur before contrast suppression or the segmentation and contrast suppression are mutually dependent. We proposed an object-based image processing model for the the human visual system.
Keywords: 579 shape, form, contour, object perception • 429 image processing • 510 perceptual organization