weSport: Utilising Wrist-Band Sensing to Detect Player Activities in Basketball Games

Wristbands have been traditionally designed to track the activities of a single person. However there is an opportunity to utilize the sensing capabilities of wristbands to offer activity tracking services within the domain of team-based sports games. In this paper we demonstrate the design of an activity tracking system capable of detecting the players’ activities within a one-to-one basketball game. Relying on the inertial sensors of wristbands and smartphones, the system can capture the shooting attempts of each player and provide statistics about their performance. The system is based on a two- level classification architecture, combining data from both players in the game. We employ a technique for semi-automatic labelling of the ground truth that requires minimum manual input during a training game. Using a single game as a training dataset, and applying the classifier on future games we demonstrate that the system can achieve a good level of accuracy detecting the shooting attempts of both players in the game (precision 91.34%, recall 94.31%)

Automated camera ranking and selection using video content and scene context

PhDWhen observing a scene with multiple cameras, an important problem to solve is to automatically identify “what camera feed should be shown and when?” The answer to this question is of interest for a number of applications and scenarios ranging from sports to surveillance. In this thesis we present a framework for the ranking of each video frame and camera across time and the camera network, respectively. This ranking is then used for automated video production. In the first stage information from each camera view and from the objects in it is extracted and represented in a way that allows for object- and frame-ranking. First objects are detected and ranked within and across camera views. This ranking takes into account both visible and contextual information related to the object. Then content ranking is performed based on the objects in the view and camera-network level information. We propose two novel techniques for content ranking namely: Routing Based Ranking (RBR) and Multivariate Gaussian based Ranking (MVG). In RBR we use a rule based framework where weighted fusion of object and frame level information takes place while in MVG the rank is estimated as a multivariate Gaussian distribution. Through experimental and subjective validation we demonstrate that the proposed content ranking strategies allows the identification of the best-camera at each time. The second part of the thesis focuses on the automatic generation of N-to-1 videos based on the ranked content. We demonstrate that in such production settings it is undesirable to have frequent inter-camera switching. Thus motivating the need for a compromise, between selecting the best camera most of the time and minimising the frequent inter-camera switching, we demonstrate that state-of-the-art techniques for this task are inadequate and fail in dynamic scenes. We propose three novel methods for automated camera selection. The first method (¡go f ) performs a joint optimization of a cost function that depends on both the view quality and inter-camera switching so that a i Abstract ii pleasing best-view video sequence can be composed. The other two methods (¡dbn and ¡util) include the selection decision into the ranking-strategy. In ¡dbn we model the best-camera selection as a state sequence via Directed Acyclic Graphs (DAG) designed as a Dynamic Bayesian Network (DBN), which encodes the contextual knowledge about the camera network and employs the past information to minimize the inter camera switches. In comparison ¡util utilizes the past as well as the future information in a Partially Observable Markov Decision Process (POMDP) where the camera-selection at a certain time is influenced by the past information and its repercussions in the future. The performance of the proposed approach is demonstrated on multiple real and synthetic multi-camera setups. We compare the proposed architectures with various baseline methods with encouraging results. The performance of the proposed approaches is also validated through extensive subjective testing

Basketball Teams as Strategic Networks

abstract: We asked how team dynamics can be captured in relation to function by considering games in the first round of the NBA 2010 play-offs as networks. Defining players as nodes and ball movements as links, we analyzed the network properties of degree centrality, clustering, entropy and flow centrality across teams and positions, to characterize the game from a network perspective and to determine whether we can assess differences in team offensive strategy by their network properties. The compiled network structure across teams reflected a fundamental attribute of basketball strategy. They primarily showed a centralized ball distribution pattern with the point guard in a leadership role. However, individual play-off teams showed variation in their relative involvement of other players/positions in ball distribution, reflected quantitatively by differences in clustering and degree centrality. We also characterized two potential alternate offensive strategies by associated variation in network structure: (1) whether teams consistently moved the ball towards their shooting specialists, measured as “uphill/downhill” flux, and (2) whether they distributed the ball in a way that reduced predictability, measured as team entropy. These network metrics quantified different aspects of team strategy, with no single metric wholly predictive of success. However, in the context of the 2010 play-offs, the values of clustering (connectedness across players) and network entropy (unpredictability of ball movement) had the most consistent association with team advancement. Our analyses demonstrate the utility of network approaches in quantifying team strategy and show that testable hypotheses can be evaluated using this approach. These analyses also highlight the richness of basketball networks as a dataset for exploring the relationships between network structure and dynamics with team organization and effectiveness.The article is published at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.004744

Automatic Mobile Video Remixing and Collaborative Watching Systems

In the thesis, the implications of combining collaboration with automation for remix creation are analyzed. We first present a sensor-enhanced Automatic Video Remixing System (AVRS), which intelligently processes mobile videos in combination with mobile device sensor information. The sensor-enhanced AVRS system involves certain architectural choices, which meet the key system requirements (leverage user generated content, use sensor information, reduce end user burden), and user experience requirements. Architecture adaptations are required to improve certain key performance parameters. In addition, certain operating parameters need to be constrained, for real world deployment feasibility. Subsequently, sensor-less cloud based AVRS and low footprint sensorless AVRS approaches are presented. The three approaches exemplify the importance of operating parameter tradeoffs for system design. The approaches cover a wide spectrum, ranging from a multimodal multi-user client-server system (sensor-enhanced AVRS) to a mobile application which can automatically generate a multi-camera remix experience from a single video. Next, we present the findings from the four user studies involving 77 users related to automatic mobile video remixing. The goal was to validate selected system design goals, provide insights for additional features and identify the challenges and bottlenecks. Topics studied include the role of automation, the value of a video remix as an event memorabilia, the requirements for different types of events and the perceived user value from creating multi-camera remix from a single video. System design implications derived from the user studies are presented. Subsequently, sport summarization, which is a specific form of remix creation is analyzed. In particular, the role of content capture method is analyzed with two complementary approaches. The first approach performs saliency detection in casually captured mobile videos; in contrast, the second one creates multi-camera summaries from role based captured content. Furthermore, a method for interactive customization of summary is presented. Next, the discussion is extended to include the role of users’ situational context and the consumed content in facilitating collaborative watching experience. Mobile based collaborative watching architectures are described, which facilitate a common shared context between the participants. The concept of movable multimedia is introduced to highlight the multidevice environment of current day users. The thesis presents results which have been derived from end-to-end system prototypes tested in real world conditions and corroborated with extensive user impact evaluation

An Outlook into the Future of Egocentric Vision

What will the future be? We wonder! In this survey, we explore the gap between current research in egocentric vision and the ever-anticipated future, where wearable computing, with outward facing cameras and digital overlays, is expected to be integrated in our every day lives. To understand this gap, the article starts by envisaging the future through character-based stories, showcasing through examples the limitations of current technology. We then provide a mapping between this future and previously defined research tasks. For each task, we survey its seminal works, current state-of-the-art methodologies and available datasets, then reflect on shortcomings that limit its applicability to future research. Note that this survey focuses on software models for egocentric vision, independent of any specific hardware. The paper concludes with recommendations for areas of immediate explorations so as to unlock our path to the future always-on, personalised and life-enhancing egocentric vision.Comment: We invite comments, suggestions and corrections here: https://openreview.net/forum?id=V3974SUk1

Semantic Management of Location-Based Services in Wireless Environments

En los últimos años el interés por la computación móvil ha crecido debido al incesante uso de dispositivos móviles (por ejemplo, smartphones y tablets) y su ubicuidad. El bajo coste de dichos dispositivos unido al gran número de sensores y mecanismos de comunicación que equipan, hace posible el desarrollo de sistemas de información útiles para sus usuarios. Utilizando un cierto tipo especial de sensores, los mecanismos de posicionamiento, es posible desarrollar Servicios Basados en la Localización (Location-Based Services o LBS en inglés) que ofrecen un valor añadido al considerar la localización de los usuarios de dispositivos móviles para ofrecerles información personalizada. Por ejemplo, se han presentado numerosos LBS entre los que se encuentran servicios para encontrar taxis, detectar amigos en las cercanías, ayudar a la extinción de incendios, obtener fotos e información de los alrededores, etc. Sin embargo, los LBS actuales están diseñados para escenarios y objetivos específicos y, por lo tanto, están basados en esquemas predefinidos para el modelado de los elementos involucrados en estos escenarios. Además, el conocimiento del contexto que manejan es implícito; razón por la cual solamente funcionan para un objetivo específico. Por ejemplo, en la actualidad un usuario que llega a una ciudad tiene que conocer (y comprender) qué LBS podrían darle información acerca de medios de transporte específicos en dicha ciudad y estos servicios no son generalmente reutilizables en otras ciudades. Se han propuesto en la literatura algunas soluciones ad hoc para ofrecer LBS a usuarios pero no existe una solución general y flexible que pueda ser aplicada a muchos escenarios diferentes. Desarrollar tal sistema general simplemente uniendo LBS existentes no es sencillo ya que es un desafío diseñar un framework común que permita manejar conocimiento obtenido de datos enviados por objetos heterogéneos (incluyendo datos textuales, multimedia, sensoriales, etc.) y considerar situaciones en las que el sistema tiene que adaptarse a contextos donde el conocimiento cambia dinámicamente y en los que los dispositivos pueden usar diferentes tecnologías de comunicación (red fija, inalámbrica, etc.). Nuestra propuesta en la presente tesis es el sistema SHERLOCK (System for Heterogeneous mobilE Requests by Leveraging Ontological and Contextual Knowledge) que presenta una arquitectura general y flexible para ofrecer a los usuarios LBS que puedan serles interesantes. SHERLOCK se basa en tecnologías semánticas y de agentes: 1) utiliza ontologías para modelar la información de usuarios, dispositivos, servicios, y el entorno, y un razonador para manejar estas ontologías e inferir conocimiento que no ha sido explicitado; 2) utiliza una arquitectura basada en agentes (tanto estáticos como móviles) que permite a los distintos dispositivos SHERLOCK intercambiar conocimiento y así mantener sus ontologías locales actualizadas, y procesar peticiones de información de sus usuarios encontrando lo que necesitan, allá donde esté. El uso de estas dos tecnologías permite a SHERLOCK ser flexible en términos de los servicios que ofrece al usuario (que son aprendidos mediante la interacción entre los dispositivos), y de los mecanismos para encontrar la información que el usuario quiere (que se adaptan a la infraestructura de comunicación subyacente)

Automatic production of personalized basketball video summaries from multi-sensored data

We propose a flexible framework for producing highly personalized basketball video summaries, by integrating contextural information, narrative user preferences on story pattern, and general production principles. Starting from the multiple streams captured by a distributed set of fixed cameras, we study the implementation of autonomous viewpoint determination and automatic temporal segment selection, and also discuss the production of visually comfortable output, by applying smoothing process to viewpoint selection and by defining efficient benefit functions to evaluate various summary organization. The efficiency of our framework is demonstrated by experimental results

Understanding and designing for control in camera operation

Kameraleute nutzen traditionell gezielt Hilfsmittel um kontrollierte Kamerabewegungen zu ermöglichen. Der technische Fortschritt hat hierbei unlängst zum Entstehen neuer Werkzeugen wie Gimbals, Drohnen oder Robotern beigetragen. Dabei wurden durch eine Kombination von Motorisierung, Computer-Vision und Machine-Learning auch neue Interaktionstechniken eingeführt. Neben dem etablierten achsenbasierten Stil wurde nun auch ein inhaltsbasierter Interaktionsstil ermöglicht. Einerseits vereinfachte dieser die Arbeit, andererseits aber folgten dieser (Teil-)Automatisierung auch unerwünschte Nebeneffekte. Grundsätzlich wollen sich Kameraleute während der Kamerabewegung kontinuierlich in Kontrolle und am Ende als Autoren der Aufnahmen fühlen. Während Automatisierung hierbei Experten unterstützen und Anfänger befähigen kann, führt sie unweigerlich auch zu einem gewissen Verlust an gewünschter Kontrolle. Wenn wir Kamerabewegung mit neuen Werkzeugen unterstützen wollen, stellt sich uns daher die Frage: Wie sollten wir diese Werkzeuge gestalten damit sie, trotz fortschreitender Automatisierung ein Gefühl von Kontrolle vermitteln? In der Vergangenheit wurde Kamerakontrolle bereits eingehend erforscht, allerdings vermehrt im virtuellen Raum. Die Anwendung inhaltsbasierter Kontrolle im physikalischen Raum trifft jedoch auf weniger erforschte domänenspezifische Herausforderungen welche gleichzeitig auch neue Gestaltungsmöglichkeiten eröffnen. Um dabei auf Nutzerbedürfnisse einzugehen, müssen sich Schnittstellen zum Beispiel an diese Einschränkungen anpassen können und ein Zusammenspiel mit bestehenden Praktiken erlauben. Bisherige Forschung fokussierte sich oftmals auf ein technisches Verständnis von Kamerafahrten, was sich auch in der Schnittstellengestaltung niederschlug. Im Gegensatz dazu trägt diese Arbeit zu einem besseren Verständnis der Motive und Praktiken von Kameraleuten bei und bildet eine Grundlage zur Forschung und Gestaltung von Nutzerschnittstellen. Diese Arbeit präsentiert dazu konkret drei Beiträge: Zuerst beschreiben wir ethnographische Studien über Experten und deren Praktiken. Sie zeigen vor allem die Herausforderungen von Automatisierung bei Kreativaufgaben auf (Assistenz vs. Kontrollgefühl). Zweitens, stellen wir ein Prototyping-Toolkit vor, dass für den Einsatz im Feld geeignet ist. Das Toolkit stellt Software für eine Replikation quelloffen bereit und erleichtert somit die Exploration von Designprototypen. Um Fragen zu deren Gestaltung besser beantworten zu können, stellen wir ebenfalls ein Evaluations-Framework vor, das vor allem Kontrollqualität und -gefühl bestimmt. Darin erweitern wir etablierte Ansätze um eine neurowissenschaftliche Methodik, um Daten explizit wie implizit erheben zu können. Drittens, präsentieren wir Designs und deren Evaluation aufbauend auf unserem Toolkit und Framework. Die Alternativen untersuchen Kontrolle bei verschiedenen Automatisierungsgraden und inhaltsbasierten Interaktionen. Auftretende Verdeckung durch graphische Elemente, wurde dabei durch visuelle Reduzierung und Mid-Air Gesten kompensiert. Unsere Studien implizieren hohe Grade an Kontrollqualität und -gefühl bei unseren Ansätzen, die zudem kreatives Arbeiten und bestehende Praktiken unterstützen.Cinematographers often use supportive tools to craft desired camera moves. Recent technological advances added new tools to the palette such as gimbals, drones or robots. The combination of motor-driven actuation, computer vision and machine learning in such systems also rendered new interaction techniques possible. In particular, a content-based interaction style was introduced in addition to the established axis-based style. On the one hand, content-based cocreation between humans and automated systems made it easier to reach high level goals. On the other hand however, the increased use of automation also introduced negative side effects. Creatives usually want to feel in control during executing the camera motion and in the end as the authors of the recorded shots. While automation can assist experts or enable novices, it unfortunately also takes away desired control from operators. Thus, if we want to support cinematographers with new tools and interaction techniques the following question arises: How should we design interfaces for camera motion control that, despite being increasingly automated, provide cinematographers with an experience of control? Camera control has been studied for decades, especially in virtual environments. Applying content-based interaction to physical environments opens up new design opportunities but also faces, less researched, domain-specific challenges. To suit the needs of cinematographers, designs need to be crafted with care. In particular, they must adapt to constraints of recordings on location. This makes an interplay with established practices essential. Previous work has mainly focused on a technology-centered understanding of camera travel which consequently influenced the design of camera control systems. In contrast, this thesis, contributes to the understanding of the motives of cinematographers, how they operate on set and provides a user-centered foundation informing cinematography specific research and design. The contribution of this thesis is threefold: First, we present ethnographic studies on expert users and their shooting practices on location. These studies highlight the challenges of introducing automation to a creative task (assistance vs feeling in control). Second, we report on a domain specific prototyping toolkit for in-situ deployment. The toolkit provides open source software for low cost replication enabling the exploration of design alternatives. To better inform design decisions, we further introduce an evaluation framework for estimating the resulting quality and sense of control. By extending established methodologies with a recent neuroscientific technique, it provides data on explicit as well as implicit levels and is designed to be applicable to other domains of HCI. Third, we present evaluations of designs based on our toolkit and framework. We explored a dynamic interplay of manual control with various degrees of automation. Further, we examined different content-based interaction styles. Here, occlusion due to graphical elements was found and addressed by exploring visual reduction strategies and mid-air gestures. Our studies demonstrate that high degrees of quality and sense of control are achievable with our tools that also support creativity and established practices

Understanding and designing for control in camera operation

Kameraleute nutzen traditionell gezielt Hilfsmittel um kontrollierte Kamerabewegungen zu ermöglichen. Der technische Fortschritt hat hierbei unlängst zum Entstehen neuer Werkzeugen wie Gimbals, Drohnen oder Robotern beigetragen. Dabei wurden durch eine Kombination von Motorisierung, Computer-Vision und Machine-Learning auch neue Interaktionstechniken eingeführt. Neben dem etablierten achsenbasierten Stil wurde nun auch ein inhaltsbasierter Interaktionsstil ermöglicht. Einerseits vereinfachte dieser die Arbeit, andererseits aber folgten dieser (Teil-)Automatisierung auch unerwünschte Nebeneffekte. Grundsätzlich wollen sich Kameraleute während der Kamerabewegung kontinuierlich in Kontrolle und am Ende als Autoren der Aufnahmen fühlen. Während Automatisierung hierbei Experten unterstützen und Anfänger befähigen kann, führt sie unweigerlich auch zu einem gewissen Verlust an gewünschter Kontrolle. Wenn wir Kamerabewegung mit neuen Werkzeugen unterstützen wollen, stellt sich uns daher die Frage: Wie sollten wir diese Werkzeuge gestalten damit sie, trotz fortschreitender Automatisierung ein Gefühl von Kontrolle vermitteln? In der Vergangenheit wurde Kamerakontrolle bereits eingehend erforscht, allerdings vermehrt im virtuellen Raum. Die Anwendung inhaltsbasierter Kontrolle im physikalischen Raum trifft jedoch auf weniger erforschte domänenspezifische Herausforderungen welche gleichzeitig auch neue Gestaltungsmöglichkeiten eröffnen. Um dabei auf Nutzerbedürfnisse einzugehen, müssen sich Schnittstellen zum Beispiel an diese Einschränkungen anpassen können und ein Zusammenspiel mit bestehenden Praktiken erlauben. Bisherige Forschung fokussierte sich oftmals auf ein technisches Verständnis von Kamerafahrten, was sich auch in der Schnittstellengestaltung niederschlug. Im Gegensatz dazu trägt diese Arbeit zu einem besseren Verständnis der Motive und Praktiken von Kameraleuten bei und bildet eine Grundlage zur Forschung und Gestaltung von Nutzerschnittstellen. Diese Arbeit präsentiert dazu konkret drei Beiträge: Zuerst beschreiben wir ethnographische Studien über Experten und deren Praktiken. Sie zeigen vor allem die Herausforderungen von Automatisierung bei Kreativaufgaben auf (Assistenz vs. Kontrollgefühl). Zweitens, stellen wir ein Prototyping-Toolkit vor, dass für den Einsatz im Feld geeignet ist. Das Toolkit stellt Software für eine Replikation quelloffen bereit und erleichtert somit die Exploration von Designprototypen. Um Fragen zu deren Gestaltung besser beantworten zu können, stellen wir ebenfalls ein Evaluations-Framework vor, das vor allem Kontrollqualität und -gefühl bestimmt. Darin erweitern wir etablierte Ansätze um eine neurowissenschaftliche Methodik, um Daten explizit wie implizit erheben zu können. Drittens, präsentieren wir Designs und deren Evaluation aufbauend auf unserem Toolkit und Framework. Die Alternativen untersuchen Kontrolle bei verschiedenen Automatisierungsgraden und inhaltsbasierten Interaktionen. Auftretende Verdeckung durch graphische Elemente, wurde dabei durch visuelle Reduzierung und Mid-Air Gesten kompensiert. Unsere Studien implizieren hohe Grade an Kontrollqualität und -gefühl bei unseren Ansätzen, die zudem kreatives Arbeiten und bestehende Praktiken unterstützen.Cinematographers often use supportive tools to craft desired camera moves. Recent technological advances added new tools to the palette such as gimbals, drones or robots. The combination of motor-driven actuation, computer vision and machine learning in such systems also rendered new interaction techniques possible. In particular, a content-based interaction style was introduced in addition to the established axis-based style. On the one hand, content-based cocreation between humans and automated systems made it easier to reach high level goals. On the other hand however, the increased use of automation also introduced negative side effects. Creatives usually want to feel in control during executing the camera motion and in the end as the authors of the recorded shots. While automation can assist experts or enable novices, it unfortunately also takes away desired control from operators. Thus, if we want to support cinematographers with new tools and interaction techniques the following question arises: How should we design interfaces for camera motion control that, despite being increasingly automated, provide cinematographers with an experience of control? Camera control has been studied for decades, especially in virtual environments. Applying content-based interaction to physical environments opens up new design opportunities but also faces, less researched, domain-specific challenges. To suit the needs of cinematographers, designs need to be crafted with care. In particular, they must adapt to constraints of recordings on location. This makes an interplay with established practices essential. Previous work has mainly focused on a technology-centered understanding of camera travel which consequently influenced the design of camera control systems. In contrast, this thesis, contributes to the understanding of the motives of cinematographers, how they operate on set and provides a user-centered foundation informing cinematography specific research and design. The contribution of this thesis is threefold: First, we present ethnographic studies on expert users and their shooting practices on location. These studies highlight the challenges of introducing automation to a creative task (assistance vs feeling in control). Second, we report on a domain specific prototyping toolkit for in-situ deployment. The toolkit provides open source software for low cost replication enabling the exploration of design alternatives. To better inform design decisions, we further introduce an evaluation framework for estimating the resulting quality and sense of control. By extending established methodologies with a recent neuroscientific technique, it provides data on explicit as well as implicit levels and is designed to be applicable to other domains of HCI. Third, we present evaluations of designs based on our toolkit and framework. We explored a dynamic interplay of manual control with various degrees of automation. Further, we examined different content-based interaction styles. Here, occlusion due to graphical elements was found and addressed by exploring visual reduction strategies and mid-air gestures. Our studies demonstrate that high degrees of quality and sense of control are achievable with our tools that also support creativity and established practices