Active contour is an effective technique for object boundary extraction in biomedical images such as blood vessel tracing or optic disc extraction in retinal images. The traditional serial realization of contour finding needs considerable processing time. This paper presents a parallel realization of the active contour model to speed up the contour convergence process. The initially drawn conto...

In this paper, a modified segmentation algorithm for printed Farsi words is presented. This algorithm is based on a previous work by Azmi that uses the conditional labeling of the upper contour to find the segmentation points. The main objective is to improve the segmentation results for low quality prints. To achieve this, various modifications on local baseline detection, contour labeling an...

In object segmentation by active contours, the initial contour is often required. Conventionally, the initial contour is provided by the user. This paper extends the conventional active contour model by incorporating feature matching in the formulation, which gives rise to a novel matching-constrained active contour. The numerical solution to the new optimization model provides an automated fra...

Lip contour detection and tracking is the most important pre-requisite for computerized speech reading. Several approaches have been proposed for lip tracking after lip contour is accurately initialized on first frame. Detection and tracking of the lip contour is an issue in speech reading. A relatively large class of lip reading algorithms are available based on lip contour analysis. In these ...

We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the t...

Automatic image segmentation is a fundamental and challenging work in image analysis. We present a stochastic contour approach that draws the contour by multiple agents stochastically, each driven by a simple policy. A contour confidence map is formed, and the image is partitioned hierarchically according to the probability of being surrounded by an average contour. The segmentation is formed b...

A variety of mechanisms have been proposed to explain illusory contour formation. However, since prior studies have focused on a single mechanism, there is no clear consensus regarding contour formation mechanisms. Here we developed a novel vivid dynamic display we call the chomping pacman that allows measurement of minute differences in contour clarity. This illusion is shown to be more vivid ...

We propose a biologically motivated computational step, called non-classical receptive field (non-CRF) inhibition, to improve contour detection in images of natural scenes. We augment a Gabor energy operator with non-CRF inhibition. The resulting contour operator responds strongly to isolated lines, edges, and contours but exhibits a weaker or no response to edges that make part of texture. As ...