A multi-stage pedestrian detection using monolithic classifiers

Despite the many efforts in finding effective feature sets or accurate classifiers for people detection, few works have addressed ways for reducing the computational burden introduced by the sliding window paradigm. This paper proposes a multi-stage procedure for refining the search for pedestrians using the HOG features and the monolithic SVM classifier. The multi-stage procedure is based on particle-based estimation of pdfs and exploits the margin provided by the classifier to draw more particles on the areas where the classifier´s response is higher. This iterative algorithm achieves the same accuracy than sliding window using less particles (and thus being more efficient) and, conversely, is more accurate when configured to work at the same computational load. Experimental results on publicly available datasets demonstrate that this method, previously proposed for boosted classifiers only, can be successfully applied to monolithic classifiers.