Single-image inverse lighting of faces with a virtual light stage

This dissertation addresses the problem of inverse lighting from a single image of a face. No information is given about the face or the imaging conditions, yet, the goal is to estimate a physically plausible lighting that reproduces plain and harsh illumination effects with respect to the appearance of the face in the given image. First, a 3D Morphable Model is fit to the 2D input face. Then, a generating set of images is rendered under all the same conditions as the input image, but different lights. Each image is rendered under a single light source with unit intensity. The light sources build a fixed set that is called a Virtual Light Stage in this dissertation. We assume that the input image belongs to the synthetic illumination cone that this generating set spans. We estimate the coefficients, so that the linear combination of the generating set is as similar as possible to the input image. To aim for more realistic illumination effects, this thesis uses a non-Lambertian reflectance that considers Fresnel specular highlights at grazing angles. Analysis and synthesis of cast shadows under complex lighting conditions is another important subject of the thesis. For the parameter estimation, two probabilistic modeling approaches are proposed. A hierarchical Bayesian model automatically suppresses inconsistencies between the generative model and the input. The nonnegative optimization algorithm finds the optimal spectral intensities of the Virtual Light Stage light sources for the input face. To enhance the performance of the algorithm on complex illumination effects, such as cast shadows, the hyperparameters of the hierarchical approach are controlled by constraints. This dissertation is a contribution to single image face and environment modeling and analysis with applications in realistic scene reconstruction, intrinsic face model decomposition, relighting and lighting design.Im Mittelpunkt der vorliegenden Arbeits steht das Thema der inversen Beleuchtung eines Einzelbildes von einem Gesicht. Darüber hinaus sind keine Informationen über das Gesicht oder die Abbildungsbedingungen vorhanden. Somit muss eine physikalisch plausible Beleuchtung geschätzt werden, die sowohl einfache als auch harte Lichteffekte in Bezug auf das Aussehen des Gesichtes in dem gegebenen Bild reproduziert. Zuerst wird ein 3D Morphable Model an das 2D Eingabegesicht angepasst. Dann wird eine generative Menge von Bildern unter genau den gleichen Bedingungen wie das Eingabebild, aber mit unterschiedlichen Beleuchtungen gerendert, indem jedes Bild unter einer einzigen Lichtquelle mit Einheitsintensität synthetisiert wird. Die Menge der Lichtquellen ist vorgegeben und wird als Virtual Light Stage bezeichnet. Es wird davon ausgegangen, dass das Eingabebild zu dem synthetischen Beleuchtungskonus gehört, den dieser generierende Satz aufspannt. Dann werden die Koeffizienten geschätzt, so dass die Linearkombination des generierenden Satzes möglichst ähnlich dem Eingangsbild ist. Um realistischere Lichteffekte zu ermöglichen, wird eine nicht-Lambert’sche Reflektanzverteilungsfunktion verwendet, die Fresnel-Reflexion bei flachen Winkeln berücksichtigt. Es wird viel Aufwand in die Analyse und Synthese von Schlagschatten unter komplexen Lichtverhältnissen investiert. Für die Parameterschätzung werden zwei probabilistische Modellierungsansätze vorgeschlagen. Ein hierarchisches Bayes’sches Modell unterdrückt automatisch Inkonsistenzen zwischen dem generativen Modell und dem Input. Der Optimierungsalgorithmus mit Nicht-Negativität als Nebenbedingung findet die optimalen spektralen Intensitäten der Virtual Light Stage für das Eingangsbild. Diese Dissertation ist ein Beitrag zur Gesichtsbild- und Umgebungsmodellierung. Einige Anwendungen des vorgeschlagenen Algorithmus sind zum Beispiel die realistische Rekonstruktion des Eingabebildes, die intrinsische Gesichtsmodellzerlegung, die Wiederbeleuchtung und der Beleuchtungsentwurf

International Responsibility of States and Victims of State-Sponsored Doping

Article published in the Michigan State International Law Review

When Sports Stand Against Human Rights: Regulating Restrictions on Athlete Speech in the Global Sports Arena

Even after the International Olympic Committee’s quick and harsh response to the “black power salute” in the 1968 Olympic Games— positing that the apolitical Olympic Games were not a suitable venue for domestic political statements—athletes continued using their platform to protest human rights violations. Should such conduct be allowed? Are athletes entitled to display their political opinions on the field? Or should athletic organizations be allowed to regulate their athletes’ protests and political speech in the arena? On the one hand, freedom of speech is a fundamental human right. On the other, sports have a long history of remaining apolitical—limiting political expression during games through formal contracts, regulations, and longstanding traditions. While international athletic organizations may have reason to remain politically neutral, this paper recommends that political speech relating to internationally agreed upon, core human rights values should be the exception

TRANSFORMATION OF COMPETENCE – THE EFFECTS OF DIGITALIZATION ON COMMUNICATORS\u27 WORK

Studying human competence in relation with digitalization is currently an under-researched area within information systems scholarship. This paper presents a response to the contemporary calls within the IS field for studying the changes brought on by the advent of digitalization. Based on indepth interviews with professional communicators, we illustrate the effects of digitalization on the formation of work related competences. Employing a new sociotechnical system approach (Neo-STS), we analyze and illustrate the effects of digitalization in multiple ways. First, we propose that any further study of competence cannot be inadvertent to the phenomenon of digitalization. Second, we suggest a new approach for studying competence in relation with digitalization as opposed to studying “digital competence”. Third, by applying a Neo-STS perspective, we provide a substantiated explanation of the transformation of competences in the work of communicators

Re-organizing for Digital Product Platforms: The Work of Vehicle Motion Engineers

As flexibility and generativity of digitized information continuously afford new possibilities, a significant challenge for organizations becomes pinpointing forms and kinds of practice that are befitting from various aspects. Two overarching digitization eras have so far determined the greatness of the challenge for organizations; ‘computerization’, and ‘the Internet’. Today, a third era of digitization is marked by the emergence of digitized products. As an increasing number of code lines and software are being incorporated in previously physical products such as cars, they can be used as complete products on one layer, and simultaneously turn into platforms enabling other firms to develop and integrate new components, content, or services on another layer. As digital product platform’s multiple design layers need to be open to various applications and agendas, their development requires new justifications and approaches for organizing work. By looking into the characteristics of digital product platforms, we discuss the shifts in the work of engineers as they engage in developing digitized products along three main courses of action. We illustrate how these courses of action are formed based on the requirements of developing digital product platforms rather than managerial presuppositions

HOMOTOPY ANALYSIS OF A FORCED NONLINEAR BEAM MODEL WITH QUADRATIC AND CUBIC NONLINEARITIES

This study investigates forced nonlinear vibrations of a simply supported Euler-Bernoulli beam on a nonlinear elastic foundation with quadratic and cubic nonlinearities. Applying the homotopy analysis method (HAM) to the spatially discretized governing equation, we derive novel analytical solutions and discuss their convergence to present nonlinear frequency responses with varying contributions of the nonlinearity coefficients. A comparison with numerical solutions is conducted and nonlinear time responses and phase planes are compared to the results from linear beam theory. The study demonstrates that apart from nonlinear problems of free vibrations, HAM is equally capable of solving strongly nonlinear problems of forced vibrations

Catheter malposition during a direct radionuclide cystography — case report

We reported a 15-year-old girl with a history of mild left vesicoureteral reflux who underwent direct radionuclide cystography in our department. Bladder catheterization was mistakenly placed in the vagina. The filling phase showed vagina and uterine cavity which was similar to vesicoureteral reflux. The procedure was repeated with correct catheterization of the bladder and no vesicoureteral reflux was noted

Primary skeletal muscle lymphoma with unusual soft tissue metastases in the stomach and pancreas detected by 18F-FDG PET/CT

A 69 y/o woman with a history of primary diffuse large B cell lymphoma in the right thigh muscle was referred for recurrence evaluation with 18F-FDG PET/CT. After routine courses of chemoradiation, MRI was done in order to evaluate treatment response with inconclusive findings. 18FDG PET/CT revealed abnormal uptake in the primary site of the disease as well as secondary involvement of stomach, pancreas, pelvic lymph nodes, and both tibiae. Our case showed the importance of 18F-FDG PET/CT in the detection of unusual soft tissue extension of lymphoma

Investigating the Effective Factors on Impulse Buying

Purpose – To investigate the impact of salesperson features factors on of subway passengers Design/methodology/approach – Based on Belk’s framework on situational factors in a sales situation, the study employed a dataset of subway station in Iran (Tehran city) and regression for analysis. Findings – It is found that, whether in the individual sample, two main factors considered significantly affected shoppers’ purchases of food or non-food products. However, situational influences on purchases varied according to the types of products bought. More importantly, the findings on the impact of some factors were consistent across three or two samples, suggesting that their external validity may be extended to certain conditions. Research limitations/implications – The study had a limitation in the selection of the stations where the interviews were conducted, so some of the findings may be station-specific rather than representative of the general population of shoppers in the nations or regions. Practical implications – The information disclosed here may help the practitioners to better understand shoppers’ (especially Chinese shoppers’) behaviour in malls and, as a consequence, to undertake more efficient marketing strategies in malls (especially in the malls in China). Originality/value – The distinguished feature of this paper is that it simultaneously examined the impacts of 2 main factors on subway passengers purchase decisions. Keywords :Buying behavior, product features ,salesperson feature