The electroencephalogram (EEG) has great attraction in emotion recognition studies due to its resistance to deceptive actions of humans. This is one of the most significant advantages of brain signals in comparison to visual or speech signals in the emotion recognition context. A major challenge in EEG-based emotion recognition is that EEG recordings exhibit varying distributions for different people as well as for the same person at different time instances. This nonstationary nature of EEG limits the accuracy of it when subject independency is the priority. The aim of this study is to increase the subject-independent recognition accuracy by exploiting pretrained state-of-the-art Convolutional Neural Network (CNN) architectures. Unlike similar studies that extract spectral band power features from the EEG readings, raw EEG data is used in our study after applying windowing, pre-adjustments and normalization. Removing manual feature extraction from the training system overcomes the risk of eliminating hidden features in the raw data and helps leverage the deep neural network’s power in uncovering unknown features. To improve the classification accuracy further, a median filter is used to eliminate the false detections along a prediction interval of emotions. This method yields a mean cross-subject accuracy of 86.56% and 78.34% on the Shanghai Jiao Tong University Emotion EEG Dataset (SEED) for two and three emotion classes, respectively. It also yields a mean cross-subject accuracy of 72.81% on the Database for Emotion Analysis using Physiological Signals (DEAP) and 81.8% on the Loughborough University Multimodal Emotion Dataset (LUMED) for two emotion classes. Furthermore, the recognition model that has been trained using the SEED dataset was tested with the DEAP dataset, which yields a mean prediction accuracy of 58.1% across all subjects and emotion classes. Results show that in terms of classification accuracy, the proposed approach is superior to, or on par with, the reference subject-independent EEG emotion recognition studies identified in literature and has limited complexity due to the elimination of the need for feature extraction.

Multimodal emotion recognition has gained traction in affective computing research community to overcome the limitations posed by the processing a single form of data and to increase recognition robustness. In this study, a novel emotion recognition system is introduced, which is based on multiple modalities including facial expressions, galvanic skin response (GSR) and electroencephalogram (EEG). This method follows a hybrid fusion strategy and yields a maximum one-subject-out accuracy of 81.2% and a mean accuracy of 74.2% on our bespoke multimodal emotion dataset (LUMED-2) for 3 emotion classes: sad, neutral and happy. Similarly, our approach yields a maximum one-subject-out accuracy of 91.5% and a mean accuracy of 53.8% on the Database for Emotion Analysis using Physiological Signals (DEAP) for varying numbers of emotion classes, 4 in average, including angry, disgust, afraid, happy, neutral, sad and surprised. The presented model is particularly useful in determining the correct emotional state in the case of natural deceptive facial expressions. In terms of emotion recognition accuracy, this study is superior to, or on par with, the reference subject-independent multimodal emotion recognition studies introduced in the literature.

The purpose of this study is to explore the effects of an affective recommendation system on the developmental trajectories of prospective teachers' emotional patterns, integrated with a Simulated Virtual Classroom (SVC) platform called SimInClass. SVC exposes teachers to a range of student discourses in the form of unexpected stimuli. Fifteen prospective teachers participated in a study consisting of two practicum sessions in the SVC. Participants did not receive any affective recommendation after the first session but did receive it after the second session. Additional data were collected during both sessions in the SVC, including the physiological responses, such as electroencephalogram (EEG), galvanic skin response (GSR), and facial expressions. L metric and Lag sequential analysis were employed in determining teachers' transitional emotional patterns. The results showed that participants did not maintain disgust after receiving affective recommendations, although they maintained sadness. This result indicates that the given affective recommendation has an inherent effect on negative emotions that are felt less intensely. Different or longer‐term interventions may be needed for more intense and long‐lasting negative discrete emotions such as sadness. Also, participants transitioned to happiness and sadness instead of maintaining their neutral status after receiving an affective recommendation. This result demonstrates that affective recommendations encourage participants to use the cognitive reappraisal necessary for emotion regulation. When the participants' emotional patterns are examined on the basis of student discourse, the results are more complex and the emotional patterns differ according to the function of the discourse triggered by virtual students. Practitioner notes: What is already known about this topic Teachers experience different emotional states during teaching. Teachers' emotions affect their behaviour management, teaching process and student engagement. It is beneficial to increase opportunities for prospective teachers' classroom experience and provide them with sufficient guidance and advice during this difficult process. What this paper adds The affective recommendation system has intervened in the persistence of short‐term and low‐intensity negative emotions. The affective recommendation system enabled prospective teachers to try to reach optimal emotional conditions through cognitive reappraisal processes. When emotional patterns are examined in light of the types of student discourse, it is noted that happy prospective teachers maintain their emotions when confronted with unexpected stimuli. However, prospective teachers in a negative valance displayed a descending pattern of activation in response to an unexpected stimulus. Implications for practice and/or policy Teacher emotions need to be taken into account in teacher education programs. SVCs can be utilized as useful tools for teacher education programs. In subsequent studies, it is suggested to explore the stimulus‐based effects of the affective recommendation system by increasing the number of stimuli according to different types of discourse and behaviour patterns.

The increase in Internet bandwidth and the developments in 3D video technology have paved the way for the delivery of 3D Multi-View Video (MVV) over the Internet. However, large amounts of data and dynamic network conditions result in frequent network congestion, which may prevent video packets from being delivered on time. As a consequence, the 3D video experience may well be degraded unless content-aware precautionary mechanisms and adaptation methods are deployed. In this work, a novel adaptive MVV streaming method is introduced which addresses the future generation 3D immersive MVV experiences with multi-view displays. When the user experiences network congestion, making it necessary to perform adaptation, the rate-distortion optimum set of views that are pre-determined by the server, are truncated from the delivered MVV streams. In order to maintain high Quality of Experience (QoE) service during the frequent network congestion, the proposed method involves the calculation of low-overhead additional metadata that is delivered to the client. The proposed adaptive 3D MVV streaming solution is tested using the MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH) standard. Both extensive objective and subjective evaluations are presented, showing that the proposed method provides significant quality enhancement under the adverse network conditions.

Quality of Experience (QoE) is becoming an important factor of User-Centred Design (UCD). The deployment of pure technical measures such as Quality of Service (QoS) parameters to assess the quality of multimedia applications is phasing out due to the failure of those methods to quantify true user satisfaction. Though significant research results and several deployments have occurred and been realized over the last few years, focusing on QoE-based multimedia technologies, several issues both of theoretical and practical importance remain open. Accordingly, the papers of this Special Issue are significant contribution samples within the general ecosystem highlighted above, ranging from QoE in the capture, processing and consumption of next-generation multimedia applications. In particular, a total of five excellent articles have been accepted, following a rigorous review process, which address many of the aforementioned challenges and beyond.

In this paper an error concealment (EC)-aware encoding scheme is proposed to improve the quality of decoded video in broadcast environments subject to transmission errors and data loss. The proposed scheme is based on a scalable coding approach where the best EC methods to be used at the decoder are optimally determined at the encoder and signalled to the decoder through supplemental enhancement information messages. Such optimal EC modes are found by simulating transmission losses, followed by a Lagrangian optimization of the signalling rate-EC distortion cost. A generalized saliency-weighted distortion is used and the residue between coded frames and their EC substitutes is encoded using a rate-controlled enhancement layer. When data loss occurs the signalling information is used by the decoder to improve the reconstruction quality. The simulation results show that the proposed method achieves consistent quality gains in comparison with other reference methods and previous works. Using only the EC mode signalling, i.e., without any residue transmitted in the enhancement layer, an average PSNR gain up to 2.95 dB is achieved, while using the full EC-aware scheme, i.e., including residue encoded in the enhancement layer, the proposed scheme outperforms other comparable methods, with a PSNR gain up to 3.79 dB.