The visibility of a local target is influenced by the global configuration of the stimulus. Collinear configurations are a specific case in which facilitation or suppression of the target has been found to be dependent on the contrast threshold of the target. The role of collinear interactions in perceptual grouping, especially in contour integration, is still controversial. In the current stud...

PURPOSE In several studies, researchers have found that integration of orientation information along contours defined by Gabor patches is abnormal in patients with strabismus and in untreated patients with anisometropic amblyopia. In this study, the rate and degree of recovery of contour-integration deficits were compared with the recovery of logMAR (logarithm of the minimum angle of resolution...

With fluoroscopic analysis of knee implant kinematics the implant contour must be detected in each image frame, followed by estimation of the implant pose. With a large number of possibly low-quality images, the contour detection is a time-consuming bottleneck. The present paper proposes an automated contour detection method, which is integrated in the pose estimation. In a phantom experiment t...

Object perception and pattern vision depend fundamentally upon the extraction of contours from the visual environment. In adulthood, contour or edge-level processing is supported by the Gestalt heuristics of proximity, collinearity, and closure. Less is known, however, about the developmental trajectory of contour detection and contour integration. Within the physiology of the visual system, lo...

We propose a biologically motivated computational step, called surround inhibition, which improves the performance of contour detectors. The mechanism of surround inhibition is exhibited by the majority of the orientation selective neurons in the primary visual cortex of macaque monkeys and has been demonstrated to influence the visual perception of man as well. We illustrate the principle and ...

The present study used an operant conditioning procedure and contour integration stimuli to test three-month-olds' sensitivity to both contour continuity and contour closure. The data demonstrate an immaturity of continuity detection and a lack of closure detection at that age, relative to a previous finding of a heightened sensitivity to closed contours in adult observers. This finding modifie...

This paper presents an object contour detection using the object shape model. First, we detect the change of background luminance ratio outside the bounding box of object. Second, the temporal segmentation is obtained by mesh based motion activity detection. A new combined mask is composed of temporal segmentation result and shape model by OR operation. Finally, for modification of the mask, we...

The automatic detection of the lip contour is relatively a difficult problem in computer vision due to the variation amongst humans and environmental conditions. In this paper we improve upon the classical methods by introducing fusion. Two separate methods are first applied, one based on edge detection and the other on region segmentation to detect the outer lip contour, the results from them ...