基于Snake模型的特定人脸三维重建方法

以双目立体视觉为基础，构建一种特定人脸重建系统，提出基于Snake模型的特定人脸三维重建方法，利用已标定的摄像机拍摄立体图像对，采用肤色检测得到人脸区域。在对立体图像对进行摄像机畸变校正、立体图像对的外极线对齐、人脸区域选择及归一化等预处理后，采用金字塔结构相关匹配算法，在误匹配点数与精度两者之间达到较好的平衡。针对人脸提出能量最小化方程，考虑顺序匹配约束、连续性约束、曲线上各点曲率的估计和相关性约束条件，大大提高视差提取的正确率，解决了立体视觉中立体匹配的难点，成功地恢复出人脸的三维数据，实现特定人脸的重建。试验结果表明：基于Snake模型的视差抽取，并经过光顺处理和纹理映射后，除了脸部部分边缘存在一些变形外，主体部分的重建效果真实感强。该算法不需要结构光等设备，基本不需要人工干预，就能恢复出特定人脸的三维数据，效果好，实用性强。

SPECIFIC FACE 3D RECONSTRUCTION BASED ON SNAKE MODEL

A reconstruction system for special human face is designed which is based on the binocular stereo vision.A 3D reconstruction method for special human face based on Snake model is presented.The stereo image pair is gathered with a calibrated camera,and the face area is segmented by skin detec-tion method.After the image pair is processed with distortion correction and epipolar line alignment,and the face area is se-lected and normalized,the correlation matching algorithm adopts pyramid structure which can balance well between error matching points and precision.An energy minimization func-tion for human face is proposed which takes into account the order matching constraint,the continuity constraint,the curva-ture estimation of every point on curve and the correlation con-straint condition.The function improves greatly the accuracy of disparity extraction,resolves the stereo matching difficulty in stereo vision area,restores successfully the 3D data of human face and realizes the reconstruction of special face.Experiments show that the algorithm which adopts the disparity extraction based on Snake model and fairing handling and texture map-ping is realistic in the reconstruction of main face part,except the deformation along partially face contour.The algorithm is effective and practical,which can restore the 3D data of special face without structured light and manual intervention.