Automatic facial expression recognition for affective computing based on bag of distances

In the recent years, the video-based approach is a popular choice for modeling and classifying facial expressions. However, this kind of methods require to segment different facial expressions prior to recognition, which might be a challenging task given real world videos. Thus, in this paper, we propose a novel facial expression recognition method based on extracting discriminative features from a still image. Our method first combines holistic and local distance-based features so that facial expressions could be characterized in more detail. The combined distance-based features are subsequently quantized to form mid-level features using the bag of words approach. The synergistic effect of these steps leads to much improved class separability and thus we can use a typical method, e.g., Support Vector Machine (SVM), to perform classification. We have performed the experiment on the Extended Cohn-Kanade (CK+) dataset. The experiment results show that the proposed scheme is efficient and accurate in facial expression recognition.