Survey of Pedestrian Detection for
Advanced Driver Assistance Systems
Advanced driver assistance systems (ADASs), and particularly pedestrian protection systems (PPSs), have become an
active research area aimed at improving traffic safety. The major challenge of PPSs is the development of reliable on-board pedestrian
detection systems. Due to the varying appearance of pedestrians (e.g., different clothes, changing size, aspect ratio, and dynamic
shape) and the unstructured environment, it is very difficult to cope with the demanded robustness of this kind of system. Two
problems arising in this research area are the lack of public benchmarks and the difficulty in reproducing many of the proposed
methods, which makes it difficult to compare the approaches. As a result, surveying the literature by enumerating the proposals
one-after-another is not the most useful way to provide a comparative point of view. Accordingly, we present a more convenient
strategy to survey the different approaches. We divide the problem of detecting pedestrians from images into different processing
steps, each with attached responsibilities. Then, the different proposed methods are analyzed and classified with respect to each
processing stage, favoring a comparative viewpoint. Finally, discussion of the important topics is presented, putting special emphasis
on the future needs and challenge.