Structured Semi-supervised Forest for Facial Landmarks Localization with Face Mask Reasoning

Despite the great success of recent facial landmarks localization approaches, the presence of occlusions significantly degrades the performance of the systems. However, very few works have addressed this problem explicitly due to the high diversity of occlusion in real world. In this paper, we address the face mask reasoning and facial landmarks localization in an unified Structured Decision Forests framework. We first assign a portion of the face dataset with face masks, i.e., for each face image we give each pixel a label to indicate whether it belongs to the face or not. Then we incorporate such additional information of dense pixel labelling into training the Structured Classification-Regression Decision Forest. The classification nodes aim at decreasing the variance of the pixel labels of the patches by using our proposed structured criterion while the regression nodes aim at decreasing the variance of the displacements between the patches and the facial landmarks. The proposed framework allows us to predict the face mask and facial landmarks locations jointly. We test the model on face images from several datasets with significant occlusion. The proposed method 1) yields promising results in face mask reasoning; 2) improves the existing Decision Forests approaches in facial landmark localization, aided by the face mask reasoning.