Hierarchical Causal Learning for Face Age Synthesis.

Abstract

Face age synthesis (FAS) predicts a person's future or past facial appearance. In FAS, modifying one facial attribute usually affects the generation of other attributes during face image generation. Current models directly learn entangled representations of age-related features, resulting in insufficient feature disentanglement, which consequently impairs their causal reasoning capability for FAS tasks. To this end, we propose a hierarchical causal learning model for face age synthesis (HCFace), which integrates hierarchical structures and causal relationships into the facial generative model. Specifically, we propose to leverage hierarchical causal relationships to align with facial features for feature disentanglement. Furthermore, we design a novel nonlinear mapping function that captures the true patterns of facial attribute changes with age, enhancing the disentanglement of these attributes. We conduct extensive experiments to validate the superiority of our proposed model. Compared to other advanced baseline methods, HCFace improves overall accuracy by 2.47%, with improvements of 9.75% and 9.69% in certain age-related attributes, such as skin and hair. Our source code is available at https://github.com/SE-hash/HCFace.