Active contours or snakes are widely used for segmentation and tracking. Recently a new active contour model was proposed, combining edge and region information. The method has a convex energy function, thus becoming invariant to the initialization of the active contour. This method is promising, but has no regularization term. Therefore segmentation results of this method are highly dependent ...

This paper presents a very efficient method for vectorizing and labeling very large raster hypsographic map images. By extending the contour tree (Freeman and Morse, 1967) to a contour graph, open contour lines and carrying contour lines can be handled. The ambiguities of the topological relationships among contour lines are resolved using map structure information, i.e., elevation tags and ind...

In this paper, a regional minimal cost approach without parameters is used for contour tracking with a good robustness. Dynamic programming is exploited for its efficiency. This general method is applied to the extraction of the cranial contour on higth resolution X-Ray image. Ellipse is then fitted on the extracted contour to represent it as a first step for automatic localisation of cephalome...

It’s hard to segment CT slices featured contour accurately and rapidly. As we all know,the segmentation of femur contour is an essential operation for the medical image 3D reconstruction, most of the software to extract the CT contour layer by layer, which is not only time-consuming but also inaccurate. According to the limitation, this paper comes up with a semi-automatic segmenting method for...

Finite elements allow smoothness to be enforced on the measurement of the image-dependent term in active contours. This improves the stability of the solution, with less computational cost than is incurred by increasing the number of elements. Performance is best when the size of the element matches the scale of the image detail sought. This property of Finite elements can be used deliberately ...

This article deals with the so called GVF (Gradient Vector Flow) introduced by C. Xu, J.L. Prince [14, 15]. We give existence and uniqueness results for the front propagation flow for boundary extraction that was initiated by Paragios, Mellina-Gottardo et Ralmesh [11, 12]. The model combines the geodesic active contour flow and the GVF to determine the geometric flow. The motion equation is con...

Locating the boundary of a head in a head-and-shoulders image is an important problem in model based coding. An approach to this problem using adaptive contour models or 'snakes' is presented. The paper provides a tutorial introduction to the theory of snakes and shows in some detail how they may be implemented using a finite difference method. Some experimental results are presented showing sn...

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 ...

In this paper, we propose a new method for fast and effective image segmentation using snakes (active contours). This method incorporates the active contour models with the wavelet transform features using directional edges in high and low frequency content sub-images. The proposed method takes advantages of these features to improve the boundary attraction process in active contour models. It ...

one patients with ischemic heart disease and 21 patients with mitral valve disease were subjected to a variety of hemodynamic interventions. These included exercise, isoproterenol infusion, and practolol, morphine or pentazocine administration. The pulse-contour estimations, using three different formulae derived by Warner, Kouchoukos, and Herd, were compared with indicator-dilution outputs. Th...