Unsupervised emotion recognition algorithm based on improved deep belief model in combination with probabilistic linear discriminant analysis

Abstract

Since the initial weight matrix between the last hidden layer of the network and the classification layer is usually generated randomly, the weight matrix does not have the discrimination ability to accurately classify the facial expression recognition, which results in that the features obtained by the weight matrix mapping cannot be guaranteed to be suitable for classification tasks. To solve this problem, a novel linear discriminant deep belief network is proposed in this paper. Firstly, the traditional linear discriminant analysis method is improved, and a new type of inter-class dispersion matrix is designed to solve the rank limitation problem in the traditional Linear Discriminant Analysis Method (LDA). Then, the weight matrix between the last hidden layer and the classification layer of the deep belief network is initialized by the improved linear discriminant analysis method, so that the network is more suitable for the classification task. In the experiments, our proposed deep network obtains respectively the recognition rates of 78.26% and 94.48% on the JAFFE database and the Extended Cohn-Kanade database. In addition, using our proposed algorithm for aggregating linear discriminant analysis into a deep belief network, we were able to produce an accuracy of 81.03% on the challenge test set.