why we use multimodal approach? 3. Steps for automatic emotion recognition 4. Get data: what kind of data could we use and how to annotate data? 5. Feature extraction approaches 6. Multichannel data fusion 7. Next steps and trends in affective computing
why we use multimodal approach? 3. Steps for automatic emotion recognition 4. Get data: what kind of data could we use and how to annotate data? 5. Feature extraction approaches 6. Multichannel data fusion 7. Next steps and trends in affective computing
2009 Affective computing lab in MIT (MIT media lab, Cambridge) http://affect.media.mit.edu/ Intelligent behavior understanding group (ICL. London) https://ibug.doc.ic.ac.uk/
Gaze Vocal Behavior Forward Posture Nonverbal behavior cues Social Signal Vinciarelli et al. Social signal processing: Survey of an emerging domain, 2009
why we use multimodal approach? 3. Steps for automatic emotion recognition 4. Get data: what kind of data could we use and how to annotate data? 5. Feature extraction approaches 6. Multichannel data fusion 7. Next steps and trends in affective computing
emotions by separate channels: voice, body language, touches, faces (the best accuracy). • Other modalities such as smell and taste also take into account during emotion recognition. • Visual and auditory modalities affect each other (e.g. facial movements around mouth region impact vocal acoustics). • fMRI, ERP studies: compared with unimodal presentations (e.g., face only), multimodal presentations (e.g., face and voice) yield faster and more accurate emotion judgments. Schirmer, Annett, and Ralph Adolphs. "Emotion perception from face, voice, and touch: comparisons and convergence." Trends in Cognitive Sciences (2017).
Even less: texts, body, physiology. • Accuracy at Multimodal data is higher than at Unimodal data: on 9,83% in average, for 85% systems. • We do not know which type and how much “channels” we need for the best classification. • The contribution of individual channels can be different: for example, models based only on audio recognized fear better, and models on visual signs – recognized disgust better. D'mello et al., 2015; Osman et al., 2017
why we use multimodal approach? 3. Steps for automatic emotion recognition 4. Get data: what kind of data could we use and how to annotate data? 5. Feature extraction approaches 6. Multichannel data fusion 7. Next steps and trends in affective computing
why we use multimodal approach? 3. Steps for automatic emotion recognition 4. Get data: what kind of data could we use and how to annotate data? 5. Feature extraction approaches 6. Multichannel data fusion 7. Next steps and trends in affective computing
why we use multimodal approach? 3. Steps for automatic emotion recognition 4. Get data: what kind of data could we use and how to annotate data? 5. Feature extraction approaches 6. Multichannel data fusion 7. Next steps and trends in affective computing
problem of localizing anatomical keypoints (body parts). • Challenges: • Each image may contain an unknown number of people • Interaction between people: contact, occlusion, limb articulation etc. • Runtime complexity tends to grow with number of people in the image • Input: a color image, output: the 2D locations of anatomical keypoints for each person in the image.
parts •Single-person pose estimation •Runtime is proportional to the number of people •If the person detector fails – no resource to recovery Bottom-up •Find keypoints & connections => construct person •Multi-person pose estimation •Robust to early commitment and have the potential to decouple runtime complexity from the number of people in the image Cao Z. et al. Realtime multi-person 2d pose estimation using part affinity fields //CVPR. – 2017. – Т. 1. – №. 2. – С. 7.
why we use multimodal approach? 3. Steps for automatic emotion recognition 4. Get data: what kind of data could we use and how to annotate data? 5. Feature extraction approaches 6. Multichannel data fusion 7. Next steps and trends in affective computing
• Training of a single model. • Problems: • Features from different channels have different time scales • Large set of features from different channels => higher computing load • Vulnerable approach in the case of Missing data
has made a decision. • Averaging, voting schemes, weighting sum, etc. • Problems: • Decision-based fusion ignores the low level interaction between the modalities.
unimodal predictors. • E.g., two steps combination: 1) feature-level fusion from audio + video, 2) decision-level fusion from the first classifier + one more classifier for physiological data.
feature-level, decision-level and hybrid-fusion approaches and did not find evidence of the advantages of any of the techniques over others. • Lingenfelser, Florian, Johannes Wagner, and Elisabeth André. "A systematic discussion of fusion techniques for multi-modal affect recognition tasks." Proceedings of the 13th international conference on multimodal interfaces. ACM, 2011 • Nevertheless, the decision-level approach seems more reasonable, because it deals better with missing data. • Al Osman, Hussein, and Tiago H. Falk. "Multimodal Affect Recognition: Current Approaches and Challenges." Emotion and Attention Recognition Based on Biological Signals and Images. InTech, 2017
why we use multimodal approach? 3. Steps for automatic emotion recognition 4. Get data: what kind of data could we use and how to annotate data? 5. Feature extraction approaches 6. Multichannel data fusion 7. Next steps and trends in affective computing