Complementary Cohort Strategy for Multimodal Face Pair Matching
Face pair matching is the task of determining whether two face images represent the same person. Due to the limited expressive information embedded in the two face images as well as various sources of facial variations, it becomes a quite difficult problem. Toward the issue of few available images provided to represent each face, we propose to exploit an extra cohort set (identities in the cohort set are different from those being compared) by a series of cohort list comparisons. Useful cohort coefficients are then extracted from both sorted cohort identities and sorted cohort images for complementary information. To augment its robustness to complicated facial variations, we further employ multiple face modalities owing to their complementary value to each other for the face pair matching task. The final decision is made by fusing the extracted cohort coefficients with the direct matching score for all the available face modalities. To investigate the capacity of each individual modality on matching faces, the cohort behavior, and the performance achieved using our complementary cohort strategy, we conduct a set of experiments on two recently collected multimodal face databases. It is shown that using different modalities leads to different face pair matching performance. For each modality, employing our cohort scheme significantly reduces the equal error rate. By applying the proposed multimodal complementary cohort strategy, we achieve the best performance on our face pair matching task.