面向纹理特征的真实感三维人脸动画方法

纹理变化是人脸表情的重要组成部分，传统的人脸动画方法通常只是对纹理图像做简单的拉伸变换，没有考虑人脸细微纹理特征的变化，比如皱纹、酒窝等，该文提出了一种面向纹理特征变化的真实感三维人脸动画方法．给出局部表情比率图(Partial Expression Ratio Image，PERI)的概念及其获取方法，在此基础上，进一步给出了面向MPEG-4的PERI参数化与面向三维人脸动画的多方向PERI方法，前者通过有机结合MPEG-4的人脸动画参数(Facial Anlmation Parameter，FAP)，实现人脸动画中细微表情特征的参数化表示；后者通过多方向PERI纹理特征调整方法，使得三维人脸模型在不同角度都具有较好的细微表情特征,该文提出的方法克服了传统人脸动画只考虑人脸曲面形变控制而忽略纹理变化的缺陷，实现面向纹理变化的具有细微表情特征的真实感三维人脸动画，实验表明，该文提出的方法能有效捕捉纹理变化细节，提高人脸动画的真实感。

Realistic 3D Facial Animations with Partial Expression Ratio Image

Texture variation is an important aspect of facial animation. Traditional facial animation techniques consider facial feature motions, but subtle changes in texture (such as wrinkles and dimples) are ignored. By applying subtle texture changes, a novel technique is presented to get realistic 3D facial animations. Firstly, the concept of PERI (partial expression ratio image) and the approach to get PERI are given. Then the PERI is parameterized according to the FAP (facial animation parameter) in the MPEG -4 based facial animation framework and the multi-view PERI technique is developed, which makes 3D facial models have expressive expression at different viewpoints. The technique overcomes the defect of traditional methods that pay attention only to geometric warping but not texture variation. Experimental results show that this technique can express subtle changes in facial expressions and thus improve the reality of facial animations.