Facial expression recognition using feature additive pooling and progressive fine‐tuning of CNN

Abstract

Facial expression recognition is one of the most important tasks in human–computer interaction, affective computing, computer vision, and related work. Feature additive pooling and progressive fine-tuning of the convolutional neural network (CNN) for facial expression recognition in a static image are introduced. Network is proposed that partially employs the visual geometry group (VGG)-face model pre-trained on a VGG-face dataset. The characteristics and distribution of the facial expression images in each database are biased according to the purpose of the publicly available facial database used. To alleviate this problem, a CNN model is developed that merges progressively fine-tuned CNNs into a single network. Experiments were carried out to validate the presented method using facial expression images from the Cohn–Kanade +, Karolinska directed emotional face, and Japanese female facial expression databases, and cross-database evaluation results show that the method is superior to state-of-the-art methods.