Domain-Incremental Continual Learning for Mitigating Bias in Facial Expression and Action Unit Recognition
This addresses fairness issues in facial analysis systems, which impact applications like surveillance and health diagnostics, but it is incremental as it applies an existing continual learning approach to bias mitigation.
The authors tackled bias in facial expression and action unit recognition by proposing domain-incremental continual learning as a bias mitigation method, showing that it outperforms other techniques on average in both accuracy and fairness metrics on RAF-DB and BP4D datasets.
As Facial Expression Recognition (FER) systems become integrated into our daily lives, these systems need to prioritise making fair decisions instead of aiming at higher individual accuracy scores. Ranging from surveillance systems to diagnosing mental and emotional health conditions of individuals, these systems need to balance the accuracy vs fairness trade-off to make decisions that do not unjustly discriminate against specific under-represented demographic groups. Identifying bias as a critical problem in facial analysis systems, different methods have been proposed that aim to mitigate bias both at data and algorithmic levels. In this work, we propose the novel usage of Continual Learning (CL), in particular, using Domain-Incremental Learning (Domain-IL) settings, as a potent bias mitigation method to enhance the fairness of FER systems while guarding against biases arising from skewed data distributions. We compare different non-CL-based and CL-based methods for their classification accuracy and fairness scores on expression recognition and Action Unit (AU) detection tasks using two popular benchmarks, the RAF-DB and BP4D datasets, respectively. Our experimental results show that CL-based methods, on average, outperform other popular bias mitigation techniques on both accuracy and fairness metrics.