The proliferation of smart mobile terminals has weakened the attention and reduced the learning efficiency of students, making them more likely to lower their heads. To quantify the classroom participation, it is helpful to detect the head raising rate (HRR) of students in classroom. To this end, this paper puts forward a novel method to recognize the HRR of students in classroom. Based on the map of predicted facial features, an extraction method was developed for the salient facial features

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... students, and used to realize model matching between facial contour and facial organ. Next, the face orientation of each student was determined by soft label coding. After that, a multi-task convolutional neural network (CNN) was constructed to detect the HRR of students. The authors also explained the regularization of the loss function, and the steps of target detection. The proposed method was proved effective through experiments. The research results provide a reference for the application of head posture recognition in other fields.