Fourier-based geometric shape prior for snakes

International audienceA novel method of snakes with shape prior is presented in this paper. We propose to add a new force which makes the curve evolve to particular shape corresponding to a template to overcome some well-known problems of snakes. The template is an instance or a sketch of the researched contour without knowing its exact geometric pose in the image. The prior information is introduced through a set of complete and locally stable invariants to Euclidean transformations (translation, rotation and scale factor) computed using Fourier Transform on contours. The method is evaluated with the segmentation of myocardial scintigraphy slices and the tracking of an object in a video sequence

Using Fourier-based shape alignment to add geometric prior to snakes

International audienceIn this paper, we present a new algorithm of snakes with geometric prior. A method of shape alignment using Fourier coefficients is introduced to estimate the Euclidean transformation between the evolving snake and a template of the searched object. This allows the definition of a new field of forces making the evolving snake to have a shape similar to the template one. Furthermore, this strategy can be used to manage several possible templates by computing a shape distance to select the best one at each iteration. The new method also solves some well-known limitations of snakes such as evolution in concave boundaries, and enhances the robustness to noise and partially occluded objects. A series of experimental results is presented to illustrate performances

Snakes avec a priori en utilisant l'alignement de formes

International audienceDans cet article, nous présentons une méthode de snakes avec a priori de forme géométrique. Nous utilisons l'alignement du snake en cours d'évolution avec une forme de référence introduite l'utilisateur pour ajouter de nouvelles forces attirant les snakes vers la forme de référence. La méthode proposée permet d'améliorer les résultats de l'algorithme dans le cas d'images bruitées, détecte des objets partiellement occultés et résout le problème d'évolution dans les zones concaves

Fourier-based invariant shape prior for snakes

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Euclidean invariant snake for joint stereo segmentation

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Geometric shape prior to region-based active contours using Fourier-based shape alignment

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