Joint Sample Enhancement and Instance-Sensitive Feature Learning for Efficient Person Search

Person search, consisting of jointly or separately trained person detection stage and person Re-ID stage, suffers from significant challenges such as inefficiency and difficulty in acquiring discriminative features. However, certain work has either turned to the end-to-end framework whose performance is limited by task conflicts or has consistently attempted to obtain more accurate bounding boxes (Bboxes). Few studies have focused on the impact of sample-specificity in person search datasets for training a fine-grain Re-ID model, and few have considered obtaining discriminative Re-ID features from Bboxes in a more efficient way. In this paper, a novel sample-enhanced and instance-sensitive (SEIE) framework is designed to boost performance. By analyzing the structure of person search framework, our method refines the two stages separately. For the detection stage, we re-design the usage of Bbox and a sample enhancement combination is proposed to further enhance the quality and quantity of Bboxes. SEC can suppress false positive detection results and randomly generate high-quality positive samples. For the Re-ID stage, we contribute an instance similarity loss to exploit the similarity between classless instances, and an Omni-scale Re-ID backbone is employed to learn more discriminative features. We obtain a more efficient and discriminative person search framework by concatenating the two stages. Extensive experiments demonstrate that our method achieves state-of-the-art performance with a high speed, and significantly outperforms other existing methods.