Download or read book A Computational Framework for Modelling the Biomechanics of Human Facial Expressions written by Tim Szu-Hsien Wu and published by . This book was released on 2014 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a computational framework for modelling the biomechanics of human facial expressions. The expressive motions are formed by intricate interactions of muscles and other soft tissues present in the face. In order to elucidate this complex mechanism, an anatomically realistic finite element (FE) model of the face was created from a set of highly detailed magnetic resonance imaging (MRI) data. A volume-preserving free-form deformation algorithm with 3-D surface data acquired from a structured-light scanner was used to transform the MRI-derived model from a supine position to an upright realistic setting. The biomechanics of the detailed facial model was characterised by the theories governing finite deformation elasticity and nonlinear contact mechanics. The elastic difference between the muscle and adipose tissues was accounted for by treating the tissue continuum as a heterogeneous medium and its mechanical behaviour was represented using a two-parameter Mooney-Rivlin constitutive model. In order to make the constitutive equations compatible to a mixed (displacement-pressure) FE formulation for incompressible bodies, a modified version of the Mooney-Rivlin model was implemented. Soft tissue de-formations were driven by the contraction of the underlying network of 3-D muscles with accurate depiction of their fibre orientations and mechanics. Frictionless unilateral and sliding contact constraints were imposed to model the interaction between the superficial soft tissue continuum and deep structures. The resulting system of nonlinear equations was solved numerically using the Netwon-Raphson method with a trust-region implementation. Visually realistic facial expressions and emotional gestures were simulated using the biomechanical model with suitable muscle activation levels. In order to achieve real-time performance for the expression prediction, a workflow based on statistical surrogate models was presented. Using the multivariate partial least squares regression model, it was demonstrated that the facial biomechanics can be emulated efficiently in real-time with reliable solutions. It was also demonstrated how these surrogate models can be implemented for the inverse problem, where the muscle activation patterns can be estimated from the experimentally determined facial expressions. Incorporating features at both the organ and tissue levels provided a framework for ac-curate and reliable prediction of facial biomechanics, as demonstrated in this thesis. Moreover, further acceleration can be achieved by emulating biomechanical behaviour using statistically-based surrogate models.

Download or read book Computational Techniques for Human Smile Analysis written by Hassan Ugail and published by Springer. This book was released on 2019-04-17 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the authors discuss the recent developments in computational techniques for automated non-invasive facial emotion detection and analysis with particular focus on the smile. By way of applications, they discuss how genuine and non-genuine smiles can be inferred, how gender is encoded in a smile and how it is possible to use the dynamics of a smile itself as a biometric feature. It is often said that the face is a window to the soul. Bearing a metaphor of this nature in mind, one might find it intriguing to understand, if any, how the physical, behavioural as well as emotional characteristics of a person could be decoded from the face itself. With the increasing deductive power of machine learning techniques, it is becoming plausible to address such questions through the development of appropriate computational frameworks. Though there are as many as over twenty five categories of emotions one could express, regardless of the ethnicity, gender or social class, across humanity, there exist six common emotions – namely happiness, sadness, surprise, fear, anger and disgust - all of which can be inferred from facial expressions. Of these facial expressions, the smile is the most prominent in social interactions. The smile bears important ramifications with beliefs such as it makes one more attractive, less stressful in upsetting situations and employers tending to promote people who smile often. Even pockets of scientific research appear to be forthcoming to validate such beliefs and claims, e.g. the smile intensity observed in photographs positively correlates with longevity, the ability to win a fight and whether a couple would stay married. Thus, it appears that many important personality traits are encoded in the smile itself. Therefore, the deployment of computer based algorithms for studying the human smiles in greater detail is a plausible avenue for which the authors have dedicated the discussions in this book.

Download or read book An Anatomically Accurate Biomechanical Model of the Human Face for Simulating Facial Expressions written by Alice Hung and published by . This book was released on 2012 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Facial animations are often generated using geometric techniques that disregard the underlying mechanics of facial structures. This thesis presents an anatomically accurate biomechanical model of the face for simulating facial expressions. The computational model uses highly accurate geometric descriptions of skin, facial muscles and the skull surface based on segmented data derived from the Visible Human cryosections published by the National US Library of Medicine. Experimental observations made using an ultrasound imaging system revealed that the superficial soft tissue layer of the face deforms as a single entity. The information acquired led to the creation of a single superficial layer of tissue continuum. Kinematical relations of the computational model were formulated using the theory of finite elasticity to predict large deformations of facial soft tissue structures. The equations governing mechanics of deformable bodies, the static Cauchy equation, and other auxiliary equations were numerically solved using the finite element method. The use of Hermite family elements in the finite element model ensures equilibrium conditions are naturally satisfied, thus more accurate solutions can be obtained. Accurate fibre orientations of facial muscles were derived from reconstructed 3D muscle models and embedded in the continuum. A novel grid based method was employed to determine the activation field of the continuum for simulating contraction of facial muscles. A frictionless contact constraint was imposed via a penalty method to prevent penetrations of facial soft tissues into the skull. An efficient customisation framework was also developed to streamline the processes for generating subject-specific models of facial structures. Furthermore, an investigation was undertaken to assess the suitability of using a coupled membrane-solid model for mechanical analyses of skin and subcutaneous tissues. Simulation results from the coupled model revealed that the assumptions made in membrane mechanics theory lead to significant errors in predicting tissue compressions. Facial expressions were successfully generated for a number of individuals using the optimal activation values inferred from experimental data followed by a validation study to assess the predictability of the model. The detailed biomechanical computational model presented in this thesis has a multitude of potential applications, ranging from facial animation in the entertainment industry to being a clinical tool in facial reconstructive procedures.

Download or read book Understanding Facial Expressions in Communication written by Manas K. Mandal and published by Springer. This book was released on 2014-10-10 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This important volume provides a holistic understanding of the cultural, psychological, neurological and biological elements involved in human facial expressions and of computational models in the analyses of expressions. It includes methodological and technical discussions by leading scholars across the world on the subject. Automated and manual analysis of facial expressions, involving cultural, gender, age and other variables, is a growing and important area of research with important implications for cross-cultural interaction and communication of emotion, including security and clinical studies. This volume also provides a broad framework for the understanding of facial expressions of emotion with inputs drawn from the behavioural sciences, computational sciences and neurosciences.

Download or read book A Computational Framework for Expressive Personality based Non verbal Behaviour for Affective 3D Character Agents written by Maryam Saberi and published by . This book was released on 2016 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Badler defined virtual humanoid characters as computer models of humans that can be used in several applications such as training and entertainment. For the humanoid characters to be credible and human-like, they must exhibit realistic and consistent nonverbal behavior. It is this consistency that ultimately instills in human users a sense that the characters have distinct personalities. Despite this importance, relatively little work has so far been done on the consistency of a 3D character's behaviour during interaction with human users and their environments. Current 3D virtual character systems lack the ability to maintain the consistency of their behaviour during real-time interaction which can lead to users' frustration and resentment.This thesis presents the design, implementation, and evaluation of a system named "RealAct" that controls the non-verbal behaviour of virtual characters. To make the virtual characters behave in a believable and consistent manner, the system controls non-verbal behavior such as gaze, facial expression, gesture and posture to give the impression of a specific personality type. The design and development of different modules of the RealAct system, e.g. for controlling the behaviour and generating emotion, is directly modelled from existing behavioural and computational literature. In addition to these core modules, the RealAct system contains a library of modules that are specifically geared toward real-time behavior control needs such as sensory inputs, scheduling of behaviour, and controlling the attention of the character.To evaluate and validate different aspects of the RealAct system, four experimental studies using both passive video-based and presential real-time paradigms were performed. The results of these experiments show that the amount of extraversion and emotional-stability that participants attributed to virtual characters depended on a combination of facial expression, gaze and posture and gestures that they exhibited. In summary, it was shown that the RealAct is effective in conveying the impression of the personality of virtual characters to users. It is hoped that the RealAct system provides a promising framework to guide the modelling of personality in virtual characters and how to create specific characters.

Download or read book Human Facial Expressions a Global and Systematic Model for Emotion Recognition written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: What man primarily sees in his continual social interactions are the faces of other persons. Starting from this vision is how he tries to infer what is happening in the bodies and minds of those individuals and then conclude if the person in question is happy, angry or in any other state of mind and thus, based on this information, modify his behavior. Using our vision system is how we analyze changes in the principal facial expressions to indirectly determine the emotion associated with these changes. Identification and recognition of emotions are therefore important abilities that facilitate the social and emotional development of people as well as being a fundamental factor of non-verbal communication. It is worth mentioning that the emotions can be expressed by diverse means, namely, bodily behaviors, vocalizations and facial expressions, being the last one mentioned, the most important. A computer system automatically capable of determining an expression related to a face, taking into account that this expression is a reflection of the persons inner state, would be of enormous utility in fields as diverse as medicine, psychology, human behavior, security, human-computer interfaces and education. Facial expression recognition is a very active research field and there are various solution proposals put forth by academic and commercial teams. Designing these systems requires knowledge in various scientific and computational fields such as: image processing, vision, artificial and computational intelligence, stochastic processes as well as psychological and physiological essentials. The work reported in this thesis takes into consideration several aspects of a computational model for the automatic detection and quantification of facial emotions based primarily on the analysis and measurement of the changes in facial expressions, which are related to a ruled-based fuzzy system which identifies and measures the intensity of the displayed emotion. Among the enormous c.

Download or read book Social Impressions of Faces written by Amanda Song and published by . This book was released on 2020 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: At first sight of a new person, people quickly form impressions on how attractive, trustworthy, and warm the person looks. Despite the dubious accuracy of these first impressions, people rely on them to navigate social interactions regarding interpersonal relationships, political voting decisions, and financial choices. As we progress into a digital era with frequent social media usage and cultural exchanges, it is crucial to understand the universal principles and cultural idiosyncrasies of impression formation from face images. In this thesis, we examine social impressions of faces through the lens of computational modeling, psychological experiments, and cultural comparisons. First, we develop a model that automatically predicts human social impression judgments using neural networks. Building on the predictive model, second, we build a generative model that can change faces holistically to augment or decrease specific characteristics, such as attractiveness and aggressiveness of a face. Third, we examine how specific physical attributes, such as hair color, affect impressions of faces, using a GAN model, and psychological experiments. Finally, we conduct a large-scale cross-cultural study, using 18 traits related to approachability, youthful-attractiveness, and competence evaluation, with Caucasian and Asian participants rating Caucasian and Asian faces. We investigate the mediating factors behind impression formation and estimate how high-level facial features such as age, eyeglasses, and smiles are judged similarly and differently by people from two cultures. Overall, our work provides a computational framework to predict and modify faces, which is practically useful in real-life scenarios regarding optimal self-image presentation. Our model lays the foundation for the quantitative study of first impressions. Our psychological and cross-cultural studies reveal the universality and culture-specific judgments mediated by high-level features that affect first impressions. These findings motivate future research in social psychology to understand the deeper cultural roots behind the differences in first impression formation and be aware of the potential bias toward certain social groups.

Download or read book Interpersonal Communication Analysis with Facial Expression Encoding and Interactional Modeling written by Taylan Kartal Sen and published by . This book was released on 2021 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this thesis, I design and validate a computational framework to improve understanding of facial expressions in honest and deceptive communication. As part of this framework, I developed the Automatic Dyadic Data Recorder (ADDR) - an online, scalable, crowd-sourced system that automates much of the work in conducting pairwise communication studies. The system recruits participants from a job crowd-sourcing platform, certifies that their computer environment is able to engage in high quality video, links two participants through video chat, and directs the two participants through the individual steps of a communication study protocol involving deception. We used ADDR to create the largest public database of 674 videos ( >65 hours of total video, >5000 questions and answers) involving deception. The data from this study enabled the development of several computational models. 1) A smile encoder based on a modified beta-mixture model. This encoder revealed 9 fundamental smile types in interpersonal communication and improved deception detection accuracy from 56.8% to 64.9%. This encoder also revealed that an exaggerated smile using both the eyes and mouth is expressed more often in deceptive witnesses, and is also used more often by successful speed daters. 2) Motivated by the interpersonal nature of nonverbal communication, an algorithm was developed to recalibrate eye gaze signals from a relative to the camera format to a relative to your conversation partner format. The interpersonal calibration improved deception classification based on eye gaze from 55.4% to 66.0%. 3) In order to capture the dynamic components of facial expressions, a dynamic model based on an LSTM architecture was developed to distinguish faces associated with imagining vs. remembering (e.g., a specific object, place, or event). This model improved our deception detection accuracy to 70%, significantly outperforming the human performance of 52%. 4) Recognizing the contextual significance of facial expression, three multimodal models were also developed, analyzing facial expressions in the context of word semantics, textual sentiment, and gender divergence. These multimodal models not only outperformed their unimodal counterparts, but also interestingly identified situations in which unimodal models identify starkly different correlations between a given facial expression type and its relation to higher level behavior - perhaps explaining some of the contradictory conclusions different studies have regarding facial expression. This thesis also addresses the ethical implications of advancing technologies that may unmask an individual's internal feelings without their consent, and provides recommendations to lawmakers of a "mental trespass" law to avoid misuse. Findings from this thesis were successfully used to model patient-doctor communication for final stage cancer patients as well as screening for the facial expression changes associated with diseases, such as Parkinson's Disease"--Pages xiv-xv.

Download or read book Computational Analysis of Facial Expressions written by A. Shenoy and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD work constitutes a series of inter-disciplinary studies that use biologically plausible computational techniques and experiments with human subjects in analyzing facial expressions. The performance of the computational models and human subjects in terms of accuracy and response time are analyzed. The computational models process images in three stages. This includes: Preprocessing, dimensionality reduction and Classification. The pre-processing of face expression images includes feature extraction and dimensionality reduction. Gabor filters are used for feature extraction as they are closest biologically plausible computational method. Various dimensionality reduction methods: Principal Component Analysis (PCA), Curvilinear Component Analysis (CCA) and Fisher Linear Discriminant (FLD) are used followed by the classification by Support Vector Machines (SVM) and Linear Discriminant Analysis (LDA). Six basic prototypical facial expressions that are universally accepted are used for the analysis. They are: angry, happy, fear, sad, surprise and disgust. The performance of the computational models in classifying each expression category is compared with that of the human subjects. The Effect size and Encoding face enable the discrimination of the areas of the face specific for a particular expression. The Effect size in particular emphasizes the areas of the face that are involved during the production of an expression. This concept of using Effect size on faces has not been reported previously in the literature and has shown very interesting results. The detailed PCA analysis showed the significant PCA components specific for each of the six basic prototypical expressions. An important observation from this analysis was that with Gabor filtering followed by non linear CCA for dimensionality reduction, the dataset vector size may be reduced to a very small number, in most cases it was just 5 components. The hypothesis that the average response time (RT) for the human subjects in classifying the different expressions is analogous to the distance measure of the data points from the classification hyper-plane was verified. This means the harder a facial expression is to classify by human subjects, the closer to the classifying hyper-plane of the classifier it is. A bi-variate correlation analysis of the distance measure and the average RT suggested a significant anti-correlation. The signal detection theory (SDT) or the d-prime determined how well the model or the human subjects were in making the classification of an expressive face from a neutral one. On comparison, human subjects are better in classifying surprise, disgust, fear, and sad expressions. The RAW computational model is better able to distinguish angry and happy expressions. To summarize, there seems to some similarities between the computational models and human subjects in the classification process.

Download or read book Automatic 3D Facial Modelling with Deformable Models written by Guofu Xiang and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Facial modelling and animation has been an active research subject in computer graphics since the 1970s. Due to extremely complex biomechanical structures of human faces and people's visual familiarity with human faces, modelling and animating realistic human faces is still one of greatest challenges in computer graphics. Since we are so familiar with human faces and very sensitive to unnatural subtle changes in human faces, it usually requires a tremendous amount of artistry and manual work to create a convincing facial model and animation. There is a clear need of developing automatic techniques for facial modelling in order to reduce manual labouring. In order to obtain a realistic facial model of an individual, it is now common to make use of 3D scanners to capture range scans from the individual and then fit a template to the range scans. However, most existing template-fitting methods require manually selected landmarks to warp the template to the range scans. It would be tedious to select landmarks by hand over a large set of range scans. Another way to reduce repeated work is synthesis by reusing existing data. One example is expression cloning, which copies facial expression from one face to another instead of creating them from scratch. This aim of this study is to develop a fully automatic framework for template-based facial modelling, facial expression transferring and facial expression tracking from range scans. In this thesis, the author developed an extension of the iterative closest points (ICP) algorithm, which is able to match a template with range scans in different scales, and a deformable model, which can be used to recover the shapes of range scans and to establish correspondences between facial models. With the registration method and the deformable model, the author proposed a fully automatic approach to reconstructing facial models and textures from range scans without re-quiring any manual interventions. In order to reuse existing data for facial modelling, the author formulated and solved the problem of facial expression transferring in the framework of discrete differential geometry. The author also applied his methods to face tracking for 4D range scans. The results demonstrated the robustness of the registration method and the capabilities of the deformable model. A number of possible directions for future work were pointed out.

Download or read book Towards Perceptual Intelligence written by Nuria Oliver and published by . This book was released on 2000 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 3D Multiscale Physiological Human written by Nadia Magnenat-Thalmann and published by Springer Science & Business Media. This book was released on 2013-12-23 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: 3D Multiscale Physiological Human aims to promote scientific exchange by bringing together overviews and examples of recent scientific and technological advancements across a wide range of research disciplines. As a result, the variety in methodologies and knowledge paradigms are contrasted, revealing potential gaps and opportunities for integration. Chapters have been contributed by selected authors in the relevant domains of tissue engineering, medical image acquisition and processing, visualization, modeling, computer aided diagnosis and knowledge management. The multi-scale and multi-disciplinary research aspects of articulations in humans are highlighted, with a particular emphasis on medical diagnosis and treatment of musculoskeletal diseases and related disorders. The need for multi-scale modalities and multi-disciplinary research is an emerging paradigm in the search for a better biological and medical understanding of the human musculoskeletal system. This is particularly motivated by the increasing socio-economic burden of disability and musculoskeletal diseases, especially in the increasing population of elderly people. Human movement is generated through a complex web of interactions between embedded physiological systems on different spatiotemporal scales, ranging from the molecular to the organ level. Much research is dedicated to the understanding of each of these systems, using methods and modalities tailored for each scale. Nevertheless, combining knowledge from different perspectives opens new venues of scientific thinking and stimulates innovation. Integration of this mosaic of multifaceted data across multiple scales and modalities requires further exploration of methods in simulations and visualization to obtain a comprehensive synthesis. However, this integrative approach cannot be achieved without a broad appreciation for the multiple research disciplines involved.

Download or read book Computer Methods in Biomechanics and Biomedical Engineering II written by Wafa Skalli and published by Springer Nature. This book was released on with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cross Modal Analysis of Speech Gestures Gaze and Facial Expressions written by Anna Esposito and published by Springer Science & Business Media. This book was released on 2009-07-14 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings together the peer-reviewed contributions of the participants at the COST 2102 International Conference on “Cross-Modal Analysis of Speech, Gestures, Gaze and Facial Expressions” held in Prague, Czech Republic, October 15–18, 2008. The conference was sponsored by COST (European Cooperation in the Field of Scientific and Technical Research, www. cost. esf. org/domains_actions/ict) in the - main of Information and Communication Technologies (ICT) for disseminating the research advances developed within COST Action 2102: “Cross-Modal Analysis of Verbal and Nonverbal Communication” http://cost2102. cs. stir. ac. uk. COST 2102 research networking has contributed to modifying the conventional theoretical approach to the cross-modal analysis of verbal and nonverbal communi- tion changing the concept of face to face communication with that of body to body communication as well as developing the idea of embodied information. Information is no longer the result of a difference in perception and is no longer measured in terms of quantity of stimuli, since the research developed in COST 2102 has proved that human information processing is a nonlinear process that cannot be seen as the sum of the numerous pieces of information available. Considering simply the pieces of inf- mation available, results in a model of the receiver as a mere decoder, and produces a huge simplification of the communication process.

Download or read book Journal of Biomechanical Engineering written by and published by . This book was released on 2009 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Skin Biophysics written by Georges Limbert and published by Springer. This book was released on 2019-05-28 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents state-of-the-art experimental and modelling techniques for skin biophysics that are currently used in academic and industrial research. It also identifies current and future challenges, as well as a growing number of opportunities in this exciting research field. The book covers the basics of skin physiology, biology, microstructural and material properties, and progressively introduces the reader to established experimental characterisation protocols and modelling approaches. Advanced topics in modelling theories and numerical implementation are also presented. The book focusses especially on: 1. Basic physiology, molecular biology, microstructural and material properties of the skin. 2. Experimental characterisation techniques for the skin (including imaging): in vivo and in vitro techniques and combination of those with in silico approaches. 3. State-of-the-art constitutive models of the skin: elastic, anelastic and mechanobiological formulations (e.g. growth, ageing, healing). 4. Applications: mechanics, damage, biological growth, healing, ageing and skin tribology. This book is addressed to postgraduate students in biomedical/mechanical/civil engineering, (bio)physics and applied mathematics, postdoctoral researchers, as well as scientists and engineers working in academia and industry engaged in skin research, particularly, if at the cross-roads of physical experiments, imaging and modelling. The book is also be of interest to clinicians/biologists who wish to learn about the possibilities offered by modern engineering techniques for skin science research and, by so doing, provide them with an incentive to broaden their outlook, engage more widely with the non-clinical research communities and, ultimately, help cross-fertilising new ideas that will lead to better treatment plans and engineering solutions.

Download or read book Computational Biomechanics for Medicine written by Adam Wittek and published by Springer. This book was released on 2017-04-29 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume comprises the latest developments in both fundamental science and patient-specific applications, discussing topics such as: cellular mechanics; injury biomechanics; biomechanics of heart and vascular system; medical image analysis; and both patient-specific fluid dynamics and solid mechanics simulations. With contributions from researchers world-wide, the Computational Biomechanics for Medicine series of titles provides an opportunity for specialists in computational biomechanics to present their latest methodologies and advancements.