中文摘要：

活动轮廓模型是计算机视觉领域的重要研究方向。针对传统的活动轮廓模型（Snake模型）对凹形轮廓处理效果差、初始轮廓必须充分接近图像边缘的缺点,通过改进外部能量项,提出了一种基于梯度矢量流活动轮廓模型的人脸轮廓提取算法。该算法把梯度矢量场作为外部能量场,克服了传统Snake模型力场范围小以及不能收敛于凹形边缘的缺点。实验结果表明,该方法能够快速、准确地提取人脸轮廓。

英文摘要：

Active contour model is an important research domain in computer vision.Aiming at the limitations that the traditional Snake model cannot converge to concave edge and the original contour must be close to the real edge of the image,a new facial contour extraction method based on Gradient Vector Flow（GVF） Snake model is proposed by improving the external energy.The algorithm uses GVF as its external energy.It not only expands the effective range of the energy field but also enhances the ability to deal with the concave edge.Experiments show that it can extract facial contour fast and exactly.