Face Association across Unconstrained Video Frames Using Conditional Random Fields

Automatic face association across unconstrained video frames has many practical applications. Recent advances in the area of object detection have made it possible to replace the traditional tracking-based association approaches with the more robust detection-based ones. However, it is still a very challenging task for real-world unconstrained videos, especially if the subjects are in a moving platform and at distances exceeding several tens of meters. In this paper, we present a novel solution based on a Conditional Random Field (CRF) framework. The CRF approach not only gives a probabilistic and systematic treatment of the problem, but also elegantly combines global and local features. When ambiguities in labels cannot be solved by using the face appearance alone, our method relies on multiple contextual features to provide further evidence for association. Our algorithm works in an on-line mode and is able to reliably handle real-world videos. Results of experiments using challenging video data and comparisons with other methods are provided to demonstrate the effectiveness of our method.