Facial Expression Recognition (FER) has long been a challenging task in the field of computer vision. Most of the existing FER methods extract facial features on the basis of face pixels, ignoring the relative geometric position dependencies of facial landmark points. This article presents a hybrid feature extraction network to enhance the discriminative power of emotional features. The proposed network consists of a Spatial Attention Convolutional Neural Network (SACNN) and a series of Long Short-term Memory networks with Attention mechanism (ALSTMs). The SACNN is employed to extract the expressional features from static face images and the ALSTMs is designed to explore the potentials of facial landmarks for expression recognition. A deep geometric feature descriptor is proposed to characterize the relative geometric position correlation of facial landmarks. The landmarks are divided into seven groups to extract deep geometric features, and the attention module in ALSTMs can adaptively estimate the importance of different landmark regions. By jointly combining SACNN and ALSTMs, the hybrid features are obtained for expression recognition. Experiments conducted on three public databases, FER2013, CK+, and JAFFE, demonstrate that the proposed method outperforms the previous methods, with the accuracies of 74.31%, 95.15%, and 98.57%, respectively. The preliminary results of Emotion Understanding Robot System (EURS) indicate that the proposed method has the potential to improve the performance of human-robot interaction.

No abstract

Population growth has made the probability of incidents at large-scale crowd events higher than ever. In the past decades, automated crowd scene analysis done by computer vision has attracted attention. However, severe occlusions and complex crowd behaviors make such analysis a challenge. As a key aspect of crowd scene analysis, a number of works dealing with dense crowd anomaly detection based on computer vision have been presented. This work is a survey of computer vision techniques for analyzing dense crowd scenes. It covers two aspects: crowd density estimation and abnormal event detection. Some problems and perspectives are discussed at the end.

The outbreak of COVID-19 has led to the shortage of medical personnel and the increasing need for nucleic acid testing. Manual oropharyngeal sampling is susceptible to inconsistency caused by fatigue and close contact could also cause healthcare personnel exposure and cross infection. The innate deficiency calls for a safer and more consistent way to collect the oropharyngeal samples. Therefore a fully autonomous oropharyngeal-swab robot system is proposed in this paper. The system is installed in a negative pressure chamber and carrying out a standardized sampling process to minimize individual sampling differences. A hierarchical throat detection algorithm is presented and multiple modality sensory information are fused to safely and accurately localize the optimum sampling location. Also, a force/position hybrid control method is adopted to ensure both accurate sampling and subject comfort. The robot system described in this paper can safely and efficiently collect the oropharyngeal sample, providing a scalable solution for large-scale Polymerase Chain Reaction (PCR) Molecular sample collection for various respiratory diseases.Note to Practitioners-During the COVID-19 pandemic, prediagnostic is essential for both prevention and treatment. Existing approaches, including nasal swab and oropharyngeal-swab, require extensive medical worker training and increase the chance of cross-infection. The robot system introduced in this paper can take oropharyngeal-swab samples from subjects with minimum human intervention, reducing medical worker exposure, alleviating the work pressure of medical staff, and speed up large quantity of sampling plan. The robot will first guide the subject into position with vocal commands, and automatically detect the optimum sampling location with a real-time machine learning algorithm. A dedicated control strategy aiming at minimizing discomfort and uniforming sample quantity is then applied to safely collect nucleic samples from the throat. Eventually, while the swab is being stored in the culture medium, a disinfection process is carried out simultaneously to prepare the robot for

No abstract