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We propose human action detection based on a successive convex matching scheme. Human actions are represented as sequences of postures and specific actions are detected in video by matching the time-coupled posture sequences to video frames. The template sequence to video registration is formulated as an optimal matching problem. Instead of directly solving(More)
We present a novel convex programming scheme to solve matching problems, focusing on the challenging problem of matching in a large search range and with cluttered background. Matching is formulated as metric labeling with L<sub>1</sub> regularization terms, for which we propose a novel linear programming relaxation method and an efficient successive(More)
In this paper we consider the problem of describing the action being performed by human figures in still images. We will attack this problem using an unsupervised learning approach, attempting to discover the set of action classes present in a large collection of training images. These action classes will then be used to label test images. Our approach uses(More)
Several color object recognition methods that are based on image retrieval algorithms attempt to discount changes of illumination in order to increase performance when test image illumination conditions differ from those that obtained when the image database was created. Here we extend the seminal method of Swain and Ballard to discount changing(More)
Multimedia data mining is the mining of high-level multimedia information and knowledge from large multimedia databases. A multimedia data mining system prototype, MultiMediaMiner, has been designed and developed. It includes the construction of a multimedia data cube which facilitates multiple dimensional analysis of multimedia data, primarily based on(More)
—Image-based rendering takes as input multiple images of an object and generates photorealistic images from novel viewpoints. This approach avoids explicitly modeling scenes by replacing the modeling phase with an object reconstruction phase. Reconstruction is achieved in two possible ways: recovering 3D point locations using multiview stereo techniques, or(More)
This paper argues that the disparity gradient subsumes various constraints for stereo matching, and can thus be used as the basis of a unified cooperative stereo algorithm. Traditionally, selection of the neighborhood support function (NSF) in cooperative stereo was left as a heuristic exercise. We present an analysis and evaluation of three families of(More)
We develop an algorithm for structured prediction with nondecomposable performance measures. The algorithm learns parameters of Markov Random Fields (MRFs) and can be applied to multivariate performance measures. Examples include performance measures such as $(F_{\beta })$ score (natural language processing), intersection over union (object category(More)
Images or videos may be imaged under diierent illuminants than models in an image or video proxy database. Changing illumination color in particular may confound recognition algorithms based on color histograms or video segmentation routines based on these. Here we show that a very simple method of discounting illumination changes is adequate for both image(More)