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... already discusses a simple example. However,by introducing adequate objective functions,the optimization problem can acquire physical meaning in the context of a computer vision task. For example,in =-=[14]-=-,by defining the distance between the distributions of the model and a candidate of the target,nonrigid objects were tracked in an image sequence under severe distortions. The distance was defined at ...

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...e can introduce a large bias in the estimated location of the target, and the resulting measure is scale variant (see [37, p. 262] for a discussion). We mention that since its original publication in =-=[18]-=-, the idea of kernel-based tracking has been exploited and developed forward by various researchers. Chen and Liu [14] experimented with the same kernel-weighted histograms, but employed the Kullback-...

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...ods such as the mean-shift algorithm use viewpoint-insensitive object appearance models to track objects through non-rigid pose changes without any prior knowledge of scene structure or camera motion =-=[4]-=-. Kalman filter extensions achieve more robust tracking of maneuvering objects through the introduction of statistical models of object and camera motion [2]. Particle filtering extensions enable trac...

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...we define the candidate region in which we formulate the HSV histogram as R(xt) � lt + stW , then a kernel density estimate K(xt) � {k(n; xt)}n=1,...,N of the color distribution at time t is given=-= by [1, 14]: k(n; xt) =-=- η � d∈R(xt) δ[bt(d) − n] (1) where δ is the delta function, η is a normalizing constant which ensures k to be a probability distribution, �N n=1 k(n; xt) = 1, and a location d could be an...

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...exemplars [34], foreground/background models [16] templates with updating [26]; prediction schemes using particle filters [17], joint probabilistic data association filters [30], kernel-based filters =-=[8]-=- [11], support vector machines [2] [36] and variational inference [35]. These algorithms usually build or learn a model of the target object first and then use it for tracking, without adapting the mo...

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...scaling, and object deformation. It is also relatively stable under rotation in depth in certain applications. Therefore, color distributions have been used successfully to track nonrigid bodies [5], =-=[26]��-=-�[28], e.g., for tracking heads [29], [28], [30], [27], hands [31], and other body parts against cluttered backgrounds from stationary or moving platforms. Color distributions have also been used for ...

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...appearance model since this is usually the most challenging to design. Although many tracking methods employ static appearance models that are either defined manually or trained using the first frame =-=[16, 8, 1]-=-, these methods tend to have difficulties tracking objects that exhibit significant appearance changes. It has been shown that in many scenarios an adaptive appearance model, which evolves during the ...