Estimation of Emotion Labels via Tensor-Based Spatiotemporal Visual Attention Analysis

This paper presents emotion label estimation via tensor-based spatiotemporal visual attention analysis. It has been reported in the fields of psychology and neuroscience that human emotions are related to two elements, their visual attention change and objects included in a target image. Therefore, the proposed method focuses on the spatiotemporal change of visual attention of human gazing at objects in the target image and constructs two neural networks which enable the emotion label estimation considering both of the above two elements. Specifically, the proposed method newly constructs a fourth-order tensor, gaze and image tensor (GIT) whose modes correspond to the width, the height and the color channel of the target image and the time axis of visual attention which is used for representing the time change. Then the first network, which consists of general tensor discriminant analysis (GTDA) and extreme learning machine (ELM), estimates the emotion label from the fourth-order GIT with concerning their visual attention change. Furthermore, the second network, which consists of pre-trained convolutoinal neural network-based feature extraction, GTDA and ELM, enables the estimation from the second-order GIT including visual features obtained from objects focused at each time. Finally, the proposed method estimates emotion labels based on decision fusion of the outputs from the two networks. Experimental results show the effectiveness of the proposed method.