Combination of high order joint derivative local binary pattern (HJDLBP) and radial partitioning for automatic facial expression recognition

One of the most representative manners which human shows his inner feelings is through facial expressions. Automatic recognition of these gestures is of great importance in human computer interaction (HCI) applications. In order to automatically recognize facial expressions, local binary patterns (LBPs), which are powerful and computationally simple descriptors, have been extensively utilized for feature extraction from facial images. To improve image description accuracy, we have employed a new version of LBP, namely high order joint derivative local binary pattern (HJDLBP) in this paper which reveals spatial relations between patterns in different resolutions. Furthermore, a rotation invariant radial partitioning paradigm is utilized to localize LBP histogram calculation regions. Using radial partitioning instead of blocking eliminates head rotation effects in real world applications and improves classification accuracy. A bunch of support vector machines are trained by feature vectors to classify different facial expressions. To evaluate the proposed method we have used known and publicly available JAFFE dataset for experiments and compared the obtained results with results from state of the art approaches which use original LBP and rectangular partitioning. The comparison results show the effectiveness of the new descriptor in combination with radial partitioning for automatic facial expression categorization.