Huang Yuchi, Liu Qingshan, Metaxas Dimitris N
Department of Computer Science, Rutgers University, New Brunswick, NJ 08854, USA.
IEEE Trans Syst Man Cybern B Cybern. 2011 Feb;41(1):287-98. doi: 10.1109/TSMCB.2010.2052240. Epub 2010 Jul 23.
This paper presents a component-based deformable model for generalized face alignment, in which a novel bistage statistical model is proposed to account for both local and global shape characteristics. Instead of using statistical analysis on the entire shape, we build separate Gaussian models for shape components to preserve more detailed local shape deformations. In each model of components, a Markov network is integrated to provide simple geometry constraints for our search strategy. In order to make a better description of the nonlinear interrelationships over shape components, the Gaussian process latent variable model is adopted to obtain enough control of shape variations. In addition, we adopt an illumination-robust feature to lead the local fitting of every shape point when light conditions change dramatically. To further boost the accuracy and efficiency of our component-based algorithm, an efficient subwindow search technique is adopted to detect components and to provide better initializations for shape components. Based on this approach, our system can generate accurate shape alignment results not only for images with exaggerated expressions and slight shading variation but also for images with occlusion and heavy shadows, which are rarely reported in previous work.
本文提出了一种基于组件的可变形模型用于广义人脸对齐,其中提出了一种新颖的双阶段统计模型来兼顾局部和全局形状特征。我们不是对整个形状进行统计分析,而是为形状组件构建单独的高斯模型,以保留更详细的局部形状变形。在每个组件模型中,集成了一个马尔可夫网络,为我们的搜索策略提供简单的几何约束。为了更好地描述形状组件之间的非线性相互关系,采用高斯过程潜在变量模型来充分控制形状变化。此外,当光照条件发生显著变化时,我们采用光照鲁棒特征来引导每个形状点的局部拟合。为了进一步提高基于组件算法的准确性和效率,采用了一种高效的子窗口搜索技术来检测组件,并为形状组件提供更好的初始化。基于这种方法,我们的系统不仅可以为具有夸张表情和轻微阴影变化的图像生成准确的形状对齐结果,还可以为具有遮挡和浓重阴影的图像生成准确结果,而此前的工作很少报道这一点。