Semi-supervised Elastic net for pedestrian counting

Pedestrian counting plays an important role in public safety and intelligent transportation. Most pedestrian counting algorithms based on supervised learning require much labeling work and rarely exploit the topological information of unlabelled data in a video. In this paper, we propose a SemiSupervised Elastic Net (SSEN) regressionmethod by utilizing sequential information between unlabelled samples and their temporally neighboring samples as a regularization term. Compared with a state-ofthe-art algorithm, extensive experiments indicate that our algorithm can not only select sparse representative features from the original feature space without losing their interpretability, but also attain superior prediction performance with only very few labelled frames. & 2010 Elsevier Ltd. All rights reserved.