Hierarchical event selection for video storyboards with a case study on snooker video visualization

Video storyboard, which is a form of video visualization, summarizes the major events in a video using illustrative visualization. There are three main technical challenges in creating a video storyboard, (a) event classification, (b) event selection and (c) event illustration. Among these challenges, (a) is highly application-dependent and requires a significant amount of application specific semantics to be encoded in a system or manually specified by users. This paper focuses on challenges (b) and (c). In particular, we present a framework for hierarchical event representation, and an importance-based selection algorithm for supporting the creation of a video storyboard from a video. We consider the storyboard to be an event summarization for the whole video, whilst each individual illustration on the board is also an event summarization but for a smaller time window. We utilized a 3D visualization template for depicting and annotating events in illustrations. To demonstrate the concepts and algorithms developed, we use Snooker video visualization as a case study, because it has a concrete and agreeable set of semantic definitions for events and can make use of existing techniques of event detection and 3D reconstruction in a reliable manner. Nevertheless, most of our concepts and algorithms developed for challenges (b) and (c) can be applied to other application areas. © 2010 IEEE

Telling people where to look in a soccer-based decision task: A nomothetic approach

Research has shown that identifiable visual search patterns characterize skilled performance of anticipation and decision-making tasks in sport. However, to date, the use of experts’ gaze patterns to entrain novices’ performance has been confined to aiming activities. Accordingly, in a first experiment, 40 participants of varying soccer experience viewed static images of oncoming soccer players and attempted to predict the direction in which those players were about to move. Multiple regression analyses showed that the sole predictor of decision-making efficiency was the time taken to initiate a saccade to the ball. In a follow-up experiment, soccer novices undertook the same task as in Experiment 1. Two experimental groups were instructed to either look at the ball, or the player’s head, as quickly as possible; a control group received no instructions. The experimental groups were fastest to make a saccade to the ball or head, respectively, but decision-making efficiency was equivalent across all three groups. The fallibility of a nomothetic approach to training eye movements is discussed

Intelligent system for interaction with virtual characters based on volumetric sensors

Dissertação de Mestrado, Engenharia Elétrica e Eletrónica, Instituto Superior de Engenharia, Universidade do Algarve, 2015A tecnologia vem sendo desenvolvida para ajudar-nos a completar ou aumentar a produtividade nas nossas tarefas diárias. Muitas das máquinas construídas têm sido progressivamente aperfeiçoadas para funcionar mais como um ser humano, usando para isso os mais variados sensores. Um dos problemas mais desafiantes que a tecnologia encontrou é como dar a uma máquina a capacidade que um "animal" tem de perceber o mundo através do seu sistema visual. Uma solução será usar na máquina sistemas inteligentes que usem visão computacional. Uma grande ajuda pode chegar da perceção de profundidade pela máquina, tornando menos complexa a deteção e a compreensão de objetos numa imagem por parte desta. Com o aparecimento de sensores volumétricos (tridimensional 3D) no mercado consumidor, aumentaram os desenvolvimentos feitos nesta área científica, permitindo assim a sua integração na maioria dos dispositivos, tais como computadores ou dispositivos móveis, a um preço muito competitivo. Os sensores volumétricos podem ser usados nas mais variadas áreas pois apesar de terem aparecido inicialmente na área dos videojogos, estendemse ainda à área de vídeo, modelação 3D, interfaces, jogos ou realidade virtual e aumentada. Esta dissertação foca essencialmente no desenvolvimento de sistemas (inteligentes) baseados em sensores volumétricos (neste caso a Microsoft Kinect) para a interação com avatares ou filmes. Quanto a aplicações na área de vídeo, foi desenvolvida uma solução onde um sensor 3D ajuda um utilizador a seguir uma narrativa que é iniciada assim que o utilizador é detetado, mudando os acontecimentos do vídeo consoante ações pré-determinadas do utilizador. O utilizador pode então mudar o rumo da história mudando de posição ou efetuando um gesto. Esta solução é ilustrada utilizando retroprojeção, existindo ainda a possibilidade de ser apresentada em modo holograma numa abordagem à escala. O descrito no anterior parágrafo pode também ser aplicada a uma solução de vertente mais comercial. Para isso, foi desenvolvido uma aplicação altamente configurável, podendo-se ajustar (em termos visuais) às necessidades de diferentes companhias. O ambiente gráfico é acompanhado por um avatar ou por um video (previamente gravado), que interage com um utilizador através de gestos, dando uma sensação mais realista devido à utilização de holografia. Ao interagir com a instalação, são registados todos os movimentos e interações efetuadas pelo utilizador para que estatísticas sejam construídas, de maneira a perceber os conteúdos com mais interesse bem como as áreas físicas com mais interação. Adicionalmente, o utilizador poderá ter a sua fotografia completa ou tipo BI extraída, podendo-lhe ser oferecidos em produtos promocionais da empresa. Devido à curta área de interação oferecida por um sensor deste tipo (Kinect), foi também desenvolvida a possibilidade de juntar vários sensores, 4 para cobrir 180º (graus) em frente da instalação ou ainda 8 para cobrir os 360º à volta da instalação, de maneira a que os utilizadores possam ser detetados por qualquer um deles e que não sejam perdidos quando atravessam para uma zona de outro sensor, ou mesmo quando saem do campo de visão dos sensores e retornam mais tarde. Apesar dos sensores referidos serem mais conhecidos na interação com um jogo virtual, jogos reais e físicos também podem beneficiar deste tipo de sensor. Neste último ponto, é apresentada uma ferramenta de realidade aumentada para snooker ou bilhar. Nesta aplicação, um sensor 3D colocado por cima da mesa, capta a área de jogo sendo depois processada para que sejam detetadas as bolas, o taco e as tabelas. Sempre que possível, esta deteção é feita usando a terceira dimensão (profundidade) oferecida por estes sensores, tornando-se por exemplo mais robusto a mudanças quanto a condições luminosas. Com estes dados é então previsto, utilizando álgebra vetorial, a trajetória da bola, sendo projetado o resultado na mesa

Uncertainty-aware video visual analytics of tracked moving objects

Vast amounts of video data render manual video analysis useless while recent automatic video analytics techniques suffer from insufficient performance. To alleviate these issues we present a scalable and reliable approach exploiting the visual analytics methodology. This involves the user in the iterative process of exploration hypotheses generation and their verification. Scalability is achieved by interactive filter definitions on trajectory features extracted by the automatic computer vision stage. We establish the interface between user and machine adopting the VideoPerpetuoGram (VPG) for visualization and enable users to provide filter-based relevance feedback. Additionally users are supported in deriving hypotheses by context-sensitive statistical graphics. To allow for reliable decision making we gather uncertainties introduced by the computer vision step communicate these information to users through uncertainty visualization and grant fuzzy hypothesis formulation to interact with the machine. Finally we demonstrate the effectiveness of our approach by the video analysis mini challenge which was part of the IEEE Symposium on Visual Analytics Science and Technology 2009

Video game training does not enhance cognitive ability: a comprehensive meta-analytic investigation

As a result of considerable potential scientific and societal implications, the possibility of enhancing cognitive ability by training has been one of the most influential topics of cognitive psychology in the last two decades. However, substantial research into the psychology of expertise and a recent series of meta-analytic reviews have suggested that various types of cognitive training (e.g., working memory training) benefit performance only in the trained tasks. The lack of skill generalization from one domain to different ones-that is, far transfer- has been documented in various fields of research such as working memory training, music, brain training, and chess. Video game training is another activity that has been claimed by many researchers to foster a broad range of cognitive abilities such as visual processing, attention, spatial ability, and cognitive control. We tested these claims with three randomeffects meta-analytic models. The first meta-analysis (k = 310) examined the correlation between video game skill and cognitive ability. The second meta-analysis (k = 315) dealt with the differences between video game players and nonplayers in cognitive ability. The third meta-analysis (k = 359) investigated the effects of video game training on participants' cognitive ability. Small or null overall effect sizes were found in all three models. These outcomes show that overall cognitive ability and video game skill are only weakly related. Importantly, we found no evidence of a causal relationship between playing video games and enhanced cognitive ability. Video game training thus represents no exception to the general difficulty of obtaining far transfer

Videogames: the new GIS?

Videogames and GIS have more in common than might be expected. Indeed, it is suggested that videogame technology may not only be considered as a kind of GIS, but that in several important respects its world modelling capabilities out-perform those of most GIS. This chapter examines some of the key differences between videogames and GIS, explores a number of perhaps-surprising similarities between their technologies, and considers which ideas might profitably be borrowed from videogames to improve GIS functionality and usability

Information needs and information-seeking behavior of combat sport coaches

This paper has as main purpose, make an approach to detect and identify information needs and information- seeking behavior of coaches in combat sports. Was applied a questionnaire to teachers of aikido, boxing, fencing, judo, karate, kendo, lima lama, wrestling and taekwondo selected by a non-probability sampling causality. In general, we find that the main topics of interest among instructors are training programs, nutrition and training diets. Moreover, coaches are more likely to use their experience, internet and courses for information. In contrast, we note that the library and the books are rarely used

Toward Simulation-Based Training Validation Protocols: Exploring 3d Stereo with Incremental Rehearsal and Partial Occlusion to Instigate and Modulate Smooth Pursuit and Saccade Responses in Baseball Batting

“Keeping your eye on the ball” is a long-standing tenet in baseball batting. And yet, there are no protocols for objectively conditioning, measuring, and/or evaluating eye-on-ball coordination performance relative to baseball-pitch trajectories. Although video games and other virtual simulation technologies offer alternatives for training and obtaining objective measures, baseball batting instruction has relied on traditional eye-pitch coordination exercises with qualitative “face validation”, statistics of whole-task batting performance, and/or subjective batter-interrogation methods, rather than on direct, quantitative eye-movement performance evaluations. Further, protocols for validating transfer-of-training (ToT) for video games and other simulation-based training have not been established in general ― or for eye-movement training, specifically. An exploratory research study was conducted to consider the ecological and ToT validity of a part-task, virtual-fastball simulator implemented in 3D stereo along with a rotary pitching machine standing as proxy for the live-pitch referent. The virtual-fastball and live-pitch simulation couple was designed to facilitate objective eye-movement response measures to live and virtual stimuli. The objective measures 1) served to assess the ecological validity of virtual fastballs, 2) informed the characterization and comparison of eye-movement strategies employed by expert and novice batters, 3) enabled a treatment protocol relying on repurposed incremental-rehearsal and partial-occlusion methods intended to instigate and modulate strategic eye movements, and 4) revealed whether the simulation-based treatment resulted in positive (or negative) ToT in the real task. Results indicated that live fastballs consistently elicited different saccade onset time responses than virtual fastballs. Saccade onset times for live fastballs were consistent with catch-up saccades that follow the smooth-pursuit maximum velocity threshold of approximately 40-70˚/sec while saccade onset times for virtual fastballs lagged in the order of 13%. More experienced batters employed more deliberate and timely combinations of smooth pursuit and catch-up saccades than less experienced batters, enabling them to position their eye to meet the ball near the front edge of home plate. Smooth pursuit and saccade modulation from treatment was inconclusive from virtual-pitch pre- and post-treatment comparisons, but comparisons of live-pitch pre- and post-treatment indicate ToT improvements. Lagging saccade onset times from virtual-pitch suggest possible accommodative-vergence impairment due to accommodation-vergence conflict inherent to 3D stereo displays