Lip Contour Extraction based on Active Shape Model and Snakes

Summary In this paper, we propose an efficient method for extracting lip contour. Lip shape deformation is modeled by a statistically deformable model based on Active Shape Model(ASM). In the traditional ASM, each landmark point is moved independently to the best matching point with lip profile model, so it deforms the lip shape to implausible one in many cases and may cause many errors for extracting a correct lip contour. In this paper, we have defined an energy function which is consisted of an internal energy and an external energy. The landmark points are moved to positions at which the total energy is minimized. The internal energy is used to minimize the difference of the displacements of adjacent landmark points and keeps the contour from bending abruptly. The external energy is what derives the contour towards matching the profile model. The experiments have been performed for many lip images, and showed very encouraging result.

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