The paper presents the Argos evaluation campaign of video content analysis tools supported by the French Techno-
Vision program. This project aims at developing the resources of a benchmark of content analysis methods and
algorithms. The paper describes the type of the evaluated tasks, the way the content set has been produced, metrics and
tools developed for the evaluations and results obtained at the end of the first phase.
This work aims at recovering the temporal structure of a broadcast tennis video from an analysis of the raw footage. Our method relies on a statistical model of the interleaving of shots, in order to group shots into predefined classes representing structural elements of a tennis video. This stochastic modeling is performed in the global framework of Hidden Markov Models (HMMs). The fundamental units are shots and transitions. In a first step, colors and motion attributes of segmented shots are used to map shots into 2 classes: game (view of the full tennis court) and not game (medium, close up views, and commercials). In a second step, a trained HMM is used to analyze the temporal interleaving of shots. This analysis results in the identification of more complex structures, such as first missed services, short rallies that could be aces or services, long rallies, breaks that are significant of the end of a game and replays that highlight interesting points. These higher-level unit structures can be used either to create summaries, or to allow non-linear browsing of the video.
In this paper we propose a photo browsing system that uses image classification results in an error tolerant manner. Images are hierarchically classified into indoor/outdoor and further into city/landscape. We employ simple classifiers based on global color histogram, wavelet subband energies and contour directions having medium recall rates around 85%. This paper delivers two contributions to cope with classification errors in the context of image browsing. The first contribution is a method to associate confidence measures to classification results. A second contribution is a browsing tool that does not reveal classification results to the user. Instead, browsing options are generated. These browsing options are thumbnails representing semantic topics such as indoor and outdoor. User studies showed that thumbnails and semantic topics are highly demanded features for a photo-browsing tool. The thumbnails are representative images from the database with high confidence values. The thumbnails are chosen context-based such that they have class labels in common with currently displayed images or usage history.