We consider the problem of image segmentation through the minimization of an energy criterion involving both region and boundary functionals. We study the derivation of these functionals using the notion of shape derivative. From the derivative, we deduce the evolution equation of an active contour that will make it evolve towards a minimum of the criterion introduced. We focus on geometric and...

The classical active contour model has two basic internal forces: tension and curvature. These forces are included to provide cohension, equal control point spacing, and locally smooth shape. These classical internal forces have undesirable attributes that are in conflict with these original desired characteristics. Tension evenly spaces the control points, but also causes the models to collaps...

We present a novel algorithm to optimize deformable contour models. It overcomes an inherent problem of traditional snakes using a dynamic intervention in the evolution of the curve so that leads to better fidelity in contour detection. In practice, the main difference from the traditional GVF snakes is the definition of a feature merit function. The proposed method solves the problem of points...

We present a segmentation method for vessels using an implicit deformable model with a soft shape prior. Blood vessels are challenging structures to segment due to their branching and thinning geometry as well as the decrease in image contrast from the root of the vessel to its thin branches. Using image intensity alone to deform a model for the task of segmentation often results in leakages at...

The traditional Snake model and GVF-Snake model set high requirements on noise and initial contour in wood cell contour extraction. To solve this problem, on the premise of considering the image texture and gray-scale information, the area information is directly introduced into the active contour extraction model through force equilibrium equation. Experiments show that the contour extracted w...

This paper proposes a novel system for the automatic detection of important anatomical structures such as the Optic Disc (OD), Blood Vessels and Macula in digital fundus retinal images. The novelty is in extraction of blood vessels and localization of macula. OD localization is done using Principle Component Analysis (PCA) followed by an active contour based approach for accurate segmentation o...

The standard geometric or geodesic active contour is a powerful segmentation method, yet it is susceptible to weak edges and image noise. We propose a new region-aided, geometric, colour active contour that integrates gradient flow forces with region constraints. These constraints are composed of image region vector flow forces obtained through the diffusion of the region segmentation map. The ...

Research in 3-D object tracking is typified by approaches which attempt to recover the six degrees of freedom of an object in each frame, e.g., [ l l , 14, 6 , 171. Once a correspondence between image and model features is determined, changes in the positions of image features in successive frames is used to update the pose of the object. Although providing accurate pose of the object at each f...

Eye gaze estimation systems calculate the direction of human eye gaze. Numerous accurate eye gaze estimation systems considering a user s head movement have been reported. Although the systems allow large head motion, they require multiple devices and complicate computation in order to obtain the geometrical positions of an eye, cameras, and a monitor. The light-reflection-based method proposed...

Automated tongue image segmentation in Chinese medicine is difficult due to two special factors: (1) There are a lot of pathological details on the surface of tongue, which have a large influence on edge extraction; (2) The shapes of tongue bodies captured from various diseases or persons are quite different, so they are impossible to be properly described by a predefined deformable template. T...