The Big Picture on Small Screens Delivering Acceptable Video Quality in Mobile TV

Mobile TV viewers can change the viewing distance and (on some devices) scale the picture to their preferred viewing ratio, trading off size for angular resolution. We investigated optimal trade-offs between size and resolution through a series of studies. Participants selected their preferred size and rated the acceptability of the visual experience on a 200ppi device at a 4: 3 aspect ratio. They preferred viewing ratios similar to living room TV setups regardless of the much lower resolution: at a minimum 14 pixels per degree. While traveling on trains people required videos with a height larger than 35mm

Event detection in soccer video based on audio/visual keywords

Master'sMASTER OF SCIENC

Extração Semi-Automática de Informação Desportiva a partir de Vídeo

Os eventos desportivos nos dias de hoje, são bastante populares, sendo visualizados pelo mundo inteiro nos mais variados dispositivos. Porém se o utilizador não tiver possibi-lidade de assistir ao evento em direto, e tendo em conta a velocidade com que a informa-ção se difunde nos dias de hoje, a probabilidade de o utilizador saber como correu o even-to (resultado, lances polémicos) antes de ter a possibilidade de o visualizar em diferido é muito grande. É nestas situações que os highlights possuem uma grande importância, pois a tendência natural do utilizador não será visualizar o evento em diferido. O que os vários utilizadores pretendem é sim visualizar as partes do evento com maior relevância. Com este projeto pretende-se gerar, de forma automática, uma base de dados asso-ciada a uma transmissão televisiva de um evento desportivo, mais especificamente de um jogo de futebol, recorrendo a várias características que se possam extrair através do pró-prio vídeo. Pretende-se combinar o processamento dos vários elementos visuais, de modo a produzir ficheiros XML com a informação associada a cada frame e momento do jogo. Para além do resumo, há a intenção de dar ao utilizador a possibilidade de executar pes-quisas específicas sobre o jogo, como todos os lances que ocorreram numa das balizas, de-tetar jogadores, detetar certos elementos e lances do jogo entre outros. Como existem imensos desportos o foco principal deste projeto, será o futebol, porém pretende-se alar-gar os algoritmos e métodos a desenvolver, posteriormente a outros eventos. Os resulta-dos obtidos foram bastante favoráveis, com percentagens de precisão que variam entre os 70% e 88%

An effective trajectory-based algorithm for ball detection and tracking with application to the analysis of broadcast sports video

Ph.DDOCTOR OF PHILOSOPH

Media of things : supporting the production and consumption of object-based media with the internet of things

Ph. D. Thesis.Visual media consumption habits are in a constant state of flux, predicting which platforms and consumption mediums will succeed and which will fail is a fateful business. Virtual Reality and Augmented Reality could be the 3D TVs that went before them, or they could push forward a new level of content immersion and radically change media production forever. Content producers are constantly trying to adapt to these shifts in habits and respond to new technologies. Smaller independent studios buoyed by their new-found audience penetration through sites like YouTube and Facebook can inherently respond to these emerging technologies faster, not weighed down by the “legacy” many. Broadcasters such as the BBC are keen to evolve their content to respond to the challenges of this new world. Producing content that is both more compelling in terms of immersion, and more responsive to technological advances in terms of input and output mediums. This is where the concept of Object-based Broadcasting was born, content that is responsive to the user consuming their content on a phone over a short period of time whilst also providing an immersive multi-screen experience for a smart home environment. One of the primary barriers to the development of Object-based Media is in a feasible set of mechanisms to generate supporting assets and adequately exploit the input and output mediums of the modern home. The underlying question here is how we build these experiences, we obviously can’t produce content for each of the thousands of combinations of devices and hardware we have available to us. I view this challenge to content makers as one of a distinct lack of descriptive and abstract detail at both ends of the production pipeline. In investigating the contribution that the Internet of Things may have to this space I first look to create well described assets in productions using embedded sensing. Detecting non-visual actions and generating detail not possible from vision alone. I then look to exploit existing datasets from production and consumption environments to gain greater understanding of generated media assets and a means to coordinate input/output in the home. Finally, I investigate the opportunities for rich and expressive interaction with devices and content in the home exploiting favourable characteristics of existing interfaces to construct a compelling control interface to Smart Home devices and Object-based experiences. I resolve that the Internet of Things is vital to the development of Object-based Broadcasting and its wider roll-out.British Broadcasting Corporatio

Quality of experience in digital mobile multimedia services

People like to consume multimedia content on mobile devices. Mobile networks can deliver mobile TV services but they require large infrastructural investments and their operators need to make trade-offs to design worthwhile experiences. The approximation of how users experience networked services has shifted from the inadequate packet level Quality of Service (QoS) to the user perceived Quality of Experience (QoE) that includes content, user context and their expectations. However, QoE is lacking concrete operationalizations for the visual experience of content on small, sub-TV resolution screens displaying transcoded TV content at low bitrates. The contribution of my thesis includes both substantive and methodological results on which factors contribute to the QoE in mobile multimedia services and how. I utilised a mix of methods in both lab and field settings to assess the visual experience of multimedia content on mobile devices. This included qualitative elicitation techniques such as 14 focus groups and 75 hours of debrief interviews in six experimental studies. 343 participants watched 140 hours of realistic TV content and provided feedback through quantitative measures such as acceptability, preferences and eye-tracking. My substantive findings on the effects of size, resolution, text quality and shot types can improve multimedia models. My substantive findings show that people want to watch mobile TV at a relative size (at least 4cm of screen height) similar to living room TV setups. In order to achieve these sizes at 35cm viewing distance users require at least QCIF resolution and are willing to scale it to a much lower angular resolution (12ppd) then what video quality research has found to be the best visual quality (35ppd). My methodological findings suggest that future multimedia QoE research should use a mixed methods approach including qualitative feedback and viewing ratios akin to living room setups to meet QoE’s ambitious scope