Robust Facial Landmark Detection via Heatmap-Offset Regression.

Abstract

Facial landmark detection aims at localizing multiple keypoints for a given facial image, which usually suffers from variations caused by arbitrary pose, diverse facial expression and partial occlusion. In this paper, we develop a two-stage regression network for facial landmark detection on unconstrained conditions. Our model consists of a Structural Hourglass Network (SHN) for detecting the initial locations of all facial landmarks based on heatmap generation, and a Global Constraint Network (GCN) for further refining the detected locations based on offset estimation. Specifically, SHN introduces an improved Inception-ResNet unit as basic building block, which can effectively improve the receptive field and learn contextual feature representations. In the meanwhile, a novel loss function with adaptive weight is proposed to make the whole model focus on the hard landmarks precisely. GCN attempts to explore the spatial contextual relationship between facial landmarks and refine the initial locations of facial landmarks by optimizing the global constraint. Moreover, we develop a pre-processing network to generate features with different scales, which will be transmitted to SHN and GCN for effective feature representations. Different from existing models, the proposed method realizes the heatmap-offset framework, which combines the outputs of heatmaps generated by SHN and coordinates estimated by GCN, to obtain an accurate prediction. The extensive experimental results on several challenging datasets, including 300W, COFW, AFLW, and 300-VW confirm that our method achieve competitive performance compared with the state-of-the-art algorithms.