基于S-LRCN的微表情识别算法

Micro-expression recognition algorithm based on separate long-term recurrent convolutional network

基于面部动态表情序列,针对静态表情缺少时间信息等问题,将空间特征与时间特征融合,利用神经网络在图像分类领域良好的特征,对需要进行细节分析的表情序列进行处理,提出基于分离式长期循环卷积网络(Separate long-term recurrent convolutional networks,S-LRCN)的微表情识别方法.首先选取微表情数据集提取面部图像序列,引入迁移学习的方法,通过预训练的卷积神经网络模型提取表情帧的空间特征,降低网络训练中过拟合的危险,并将视频序列的提取特征输入长短期记忆网络(Long short-team memory,LSTM)处理时域特征.最后建立学习者表情序列小型数据库,将该方法用于辅助教学评价.

With the rapid development of machine learning and deep neural network and the popularization of intelligent devices,face recognition technology has rapidly developed.At present,the accuracy of face recognition has exceeded that of the human eyes.Moreover,the software and hardware conditions of large-scale popularization are available,and the application fields are widely distributed.As an important part of face recognition technology,facial expression recognition has been a widely studied subject in the fields of artificial intelligence,security,automation,medical treatment,and driving in recent years.Expression recognition,an active research area in human–computer interaction,involves informatics and psychology and has good research prospect in teaching evaluation.Micro-expression,which has great research significance,is a kind of short-lived facial expression that humans unconsciously make when trying to hide some emotion.Different from the general static facial expression recognition,to realize micro-expression recognition,besides extracting the spatial feature information of facial expression deformation in the image,the temporal-motion information of the continuous image sequence also needs to be considered.In this study,given that static expression features lack temporal information,so that the subtle changes in expression cannot be fully reflected,facial dynamic expression sequences were used to fuse spatial features and temporal features,and neural networks were used to provide good features in the field of image classification.Expression sequences were processed,and a micro-expression recognition method based on separate long-term recurrent convolutional network(S-LRCN)was proposed.First,the micro-expression data set was selected to extract the facial image sequence,and the transfer learning method was introduced to extract the spatial features of the expression frame through the pre-trained convolution neural network model,to reduce the risk of overfitting in the network training,and the extracted features of the video sequence were inputted into long short-term memory(LSTM)to process the temporal-domain features.Finally,a small database of learners’expression sequences was established,and the method was used to assist teaching evaluation.