Handling Occlusions with Franken-Classifiers

Markus Mathias, Rodrigo Benenson, Radu Timofte, Luc Van Gool; Proceedings of the IEEE International Conference on Computer Vision (ICCV), 2013, pp. 1505-1512

Detecting partially occluded pedestrians is challenging. A common practice to maximize detection quality is to train a set of occlusion-specific classifiers, each for a certain amount and type of occlusion. Since training classifiers is expensive, only a handful are typically trained. We show that by using many occlusion-specific classifiers, we outperform previous approaches on three pedestrian datasets; INRIA, ETH, and Caltech USA. We present a new approach to train such classifiers. By reusing computations among different training stages, 16 occlusion-specific classifiers can be trained at only one tenth the cost of one full training. We show that also test time cost grows sub-linearly.