文件名称:Statistical Change Detection by the Pool Adjacent Violators Algorithm
文件大小:2.11MB
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更新时间:2014-04-06 03:19:19
Statistical Change Detection
In this paper we present a statistical change detection approach aimed at being robust with respect to the main disturbance factors acting in real-world applications, such as illumination changes, camera gain and exposure variations, noise. We rely on modeling the effects of disturbance factors on images as locally order-preserving transformations of pixel intensities plus additive noise. This allows us to identify within the space of all the possible image change patterns the subspace corresponding to disturbance factors effects. Hence, scene changes can be detected by a-contrario testing the hypothesis that the measured pattern is due to disturbance factors, that is by computing a distance between the pattern and the subspace. By assuming additive gaussian noise, the distance can be computed within a maximum likelihood non-parametric isotonic regression framework. In particular, the projection of the pattern onto the subspace is computed by an O(N) iterative procedure known as Pool Adjacent Violators algorithm.