“…To address this, researchers came by different approaches to provide good samples for tracking using context [18,23], saliency maps [25], confidence maps [44], and optical flow [22]. Adaptive weights for the samples based on their appearance similarity to the target [35], occlusion state [30], and spatial distance to previous target location [47] have also been considered, however, selecting an efficient subset for classifier re-training have been ignored, as most of the trackers retrain on all of the data, a randomized subset of it [32], or in special cases re-sample the training data based on their boosting value [28]. A "clean" subset of training samples to re-train the classifier can achieve much higher performance than the full set [36,51], therefore, a principled ordering and selection of the samples reduces the cost of labeling and accelerate the performance with smaller re-training sample size [45].…”