Abstract
Person re-identification is a challenging problem of matching observations of individuals across non-overlapping camera views. When pedestrians walk across disjoint camera views, continuous motion information is lost, and thus re-identification mainly relies on appearance matching. Person re-identification is actually a special case of near duplicate search in image retrieval. Given a probe, our task is to find the image containing the same person in galleries. At present many state-of-the-art methods in image retrieval are based on the Bag-of-Words (BOW) model. By adapting the BOW model to our task, Bag-of-Ensemble-Colors (BOEC) is proposed to tackle person re-identification in this paper. We combine low-level color histogram and semantic color names to represent human appearances. Meanwhile, some mature and efficient techniques in image retrieval are employed in the model containing soft quantization, burstiness punishing strategy, and negative evidence. In consideration apriori knowledge of human body structure, efficient spatial constraints are proposed to weaken the influence of background. Extensive experiments on VIPeR and ETHZ databases are performed to test the effectiveness of our approach, and promising results are obtained in the public databases. Compared with other unsupervised methods, we obtain state-of-the-art performances. The recognition rate is 32.23% on VIPeR dataset, 87% on ETHZ SEQ.#1, 83% on ETHZ SEQ.#2, and 91% on ETHZ SEQ.#3.
