Enhanced tracking and recognition of moving objects by reasoning about spatio-temporal continuity.

A framework for the logical and statistical analysis and annotation of dynamic scenes containing occlusion and other uncertainties is presented. This framework consists of three elements; an object tracker module, an object recognition/classification module and a logical consistency, ambiguity and error reasoning engine. The principle behind the object tracker and object recognition modules is to reduce error by increasing ambiguity (by merging objects in close proximity and presenting multiple hypotheses). The reasoning engine deals with error, ambiguity and occlusion in a unified framework to produce a hypothesis that satisfies fundamental constraints on the spatio-temporal continuity of objects. Our algorithm finds a globally consistent model of an extended video sequence that is maximally supported by a voting function based on the output of a statistical classifier. The system results in an annotation that is significantly more accurate than what would be obtained by frame-by-frame evaluation of the classifier output. The framework has been implemented and applied successfully to the analysis of team sports with a single camera. Key words: Visua

An Efficient Multiple Object Vision Tracking System using Bipartite Graph Matching

For application domains like 11 vs. 11 robot soccer league, crowd surveillance and air traffic control, vision systems need to be able to identify and maintain information in real time about multiple objects as they move through an environment using video images. In this paper, we reduce the multi-object tracking problem to a bipartite graph matching and present efficient techniques that compute the optimal matching in real time. We demonstrate the robustness of our system on a task of tracking indistinguishable objects. One of the advantages of our tracking system is that it requires a much lower frame rate than standard tracking systems to reliably keep track of multiple objects

Development of a tracking system using invisible markers for association football

Mestrado em Treino DesportivoNowadays in association football, obtaining information such as position and movements of the players is of great interest to coaches due to the potential to relate performance to tactics and to assist in planning training programs. Over the last decade, technological advances in this area included the introduction of more sophisticated systems that are being used in elite association football; however, the development of a fully automated system is still needed. The aim of this study is to contribute to the development of a non-intrusive, automatic, tracking system, using a marker invisible to humans. We select a marker that absorbs in the infrared region (IR) of the electromagnetic spectrum (Epolight 1110) and prepared solutions containing the marker. We tested the solutions in fabric samples to assess the tones of gray, as well as the resistance of the marker to water. T-shirts were soaked in the solutions created, and were used by football players in a 1vs2 in situ task where we proceeded to the tracking. The findings showed that this approach is a valid possibility to discriminate and track players. We concluded that it is possible to use IR markers to distinguish different players and, with the appropriate computer graphics’ algorithms, to automatically track the players.Actualmente no futebol, a obtenção de informações como posição e movimentos dos jogadores é de grande interesse por parte dos técnicos devido ao potencial para relacionar o desempenho à táctica e ajudar na elaboração dos programas de treino. Durante a última década, avanços tecnológicos nesta área incluíram a introdução de sistemas mais sofisticados que estão a ser utilizados no futebol de elite; no entanto, o desenvolvimento de um sistema totalmente automatizado ainda é necessário. O objectivo deste estudo é contribuir para o desenvolvimento de um sistema de tracking não-intrusivo, automático, usando um marcador invisível para os seres humanos. Seleccionámos um marcador que absorve na região do infravermelho (IV) do espectro electromagnético (Epolight 1110) e preparámos soluções contendo o marcador. Testámos as soluções em amostras de tecido para avaliar os tons de cinzento, assim como a resistência do marcador à água. Foram embebidas T-shirts com as soluções criadas, que foram usadas por jogadores de futebol numa situação in situ de 1vs2 onde se procedeu ao tracking dos mesmos. Os resultados mostraram que esta abordagem é válida para discriminar e acompanhar os jogadores. Concluímos que é possível usar marcadores IV para distinguir diferentes jogadores e, com algoritmos de computação gráfica adequados, é possível monitorizar automaticamente os jogadores

A Novel and Effective Short Track Speed Skating Tracking System

This dissertation proposes a novel and effective system for tracking high-speed skaters. A novel registration method is employed to automatically discover key frames to build the panorama. Then, the homography between a frame and the real world rink can be generated accordingly. Aimed at several challenging tracking problems of short track skating, a novel multiple-objects tracking approach is proposed which includes: Gaussian mixture models (GMMs), evolving templates, constrained dynamical model, fuzzy model, multiple templates initialization, and evolution. The outputs of the system include spatialtemporal trajectories, velocity analysis, and 2D reconstruction animations. The tracking accuracy is about 10 cm (2 pixels). Such information is invaluable for sports experts. Experimental results demonstrate the effectiveness and robustness of the proposed system

Image analysis of sports events

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major de Automação). Faculdade de Engenharia. Universidade do Porto. 200

Joint Visual and Wireless Tracking System

Object tracking is an important component in many applications including surveillance, manufacturing, inventory tracking, etc. The most common approach is to combine a surveillance camera with an appearance-based visual tracking algorithm. While this approach can provide high tracking accuracy, the tracker can easily diverge in environments where there are much occlusions. In recent years, wireless tracking systems based on different frequency ranges are becoming more popular. While systems using ultra-wideband frequencies suffer similar problems as visual systems, there are systems that use frequencies as low as in those in the AM band to circumvent the problems of obstacles, and exploit the near-field properties between the electric and magnetic waves to achieve tracking accuracy down to about one meter. In this dissertation, I study the combination of a visual tracker and a low-frequency wireless tracker to improve visual tracking in highly occluded area. The proposed system utilizes two homographies formed between the world coordinates with the image coordinates of the head and the foot of the target person. Using the world coordinate system, the proposed system combines a visual tracker and a wireless tracker in an Extended Kalman Filter framework for joint tracking. Extensive experiments have been conducted using both simulations and real videos to demonstrate the validity of our proposed scheme