一种基于椭圆变形模板的唇动跟踪算法  

Lip-tracking algorithm based on elliptical deformable templates

作　　者：邹益民[1] 汪渤[2] 

机构地区：[1]兰州石化职业技术学院,甘肃730060 [2]北京理工大学信息技术学院自动控制系,北京100081

出　　处：《仪器仪表学报》2007年第3期514-518,共5页Chinese Journal of Scientific Instrument

摘　　要：本文给出了一种新的唇动跟踪算法框架,算法结合目标的形状、运动及彩色信息,综合利用可变形模板、光流、Kalman滤波技术,得到一种快速、鲁棒的跟踪结果。该算法使用多条椭圆弧段构成唇模板,基于彩色YCrCb信息进行光流估计,由于利用模型约束的特征光流技术,故不需加入任何附加的平滑性约束;最后借助扩展Kalman(EKF)滤波器将形状与运动信息有机结合起来,给出有效的融合解,而不必直接计算光流;该算法同时利用光流测量方程给出的误差测度及EKF给出的估计方差对虚假边缘点做出判断与舍弃,提高了算法的鲁棒性。文中还给出了相应的实例。A new lip-tracking algorithm based on deformable template, optical flow and the extended Kalman filter techniques is proposed, which combines the shape, motion and color cues of the object in image to acquire a fast and robust scheme of lip tracking. The algorithm uses several elliptical arcs as deformable template to capture the edge of the lip. With no needs of any special smoothness constraint, the optical flow is estimated by model-based optical flow method in YCrCb color space. By using extended Kalman filter, the measurements of shape and motion are naturally integrated to provide an effective fusion solution without explicit calculation of optical flow. Besides, an optical-flow based measurement error and the estimated covariance given by the EKF filter are used to detect and reject the contour sample points introduced by noise, or spurious edge to improve the robust of the scheme. Experiment results are presented to validate the algorithm.

关 键 词：唇跟踪 动态轮廓线 变形模板 光流 EKF滤波 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]