TP-FER: An Effective Three-phase Noise-tolerant Recognizer for Facial Expression Recognition
Junjie Li, Jin Yuan, Zhiyong Li · ACM Transactions on Multimedia Computing Communications and Applications · 2022
Single-label facial expression recognition (FER), which aims to classify single expression for facial images, usually suffers from the label noisy and incomplete problem, where manual annotations for partial training images exist wrong or incomplete labels, resulting in performance decline. Although prior work has attempted to leverage external sources or manual annotations to handle this problem, it usually requires extra costs. This article explores a simple yet effective three-phase paradigm (“warm-up,” “selection,” and “relabeling”) for FER task. First, the warm-up phase attempts to build an initial recognition network based on noisy samples for discriminative feature extractions and facial expression predictions. Then, the second selection phase defines several rules to choose high confident samples according to prediction scores, and the third relabeling phase assigns two potential labels to those samples for network updating according to a composite two-label loss. Compared with the previous studies, the three-phase learning could effectively correct noisy labels in the ground truth without extra information and automatically assign two potential labels to single-label samples without manual annotations. As a result, the label information is purified and supplemented with few cost, yielding significant performance improvement. Extensive experiments are conducted on three datasets, and the experimental results demonstrate that our approach is robust to noisy training samples and outperforms several state-of-the-art methods.