Papers › CA-Jaccard: Camera-aware Jaccard Distance for Person Re-identification

CA-Jaccard: Camera-aware Jaccard Distance for Person Re-identification

17 Nov 2023CVPR 2024 1arXiv:2311.10605archive 2025-07-28

Yiyu Chen, Zheyi Fan, Zhaoru Chen, Yixuan Zhu

Person re-identification (re-ID) is a challenging task that aims to learn discriminative features for person retrieval. In person re-ID, Jaccard distance is a widely used distance metric, especially in re-ranking and clustering scenarios. However, we discover that camera variation has a significant negative impact on the reliability of Jaccard distance. In particular, Jaccard distance calculates the distance based on the overlap of relevant neighbors. Due to camera variation, intra-camera samples dominate the relevant neighbors, which reduces the reliability of the neighbors by introducing intra-camera negative samples and excluding inter-camera positive samples. To overcome this problem, we propose a novel camera-aware Jaccard (CA-Jaccard) distance that leverages camera information to enhance the reliability of Jaccard distance. Specifically, we design camera-aware k-reciprocal nearest neighbors (CKRNNs) to find k-reciprocal nearest neighbors on the intra-camera and inter-camera ranking lists, which improves the reliability of relevant neighbors and guarantees the contribution of inter-camera samples in the overlap. Moreover, we propose a camera-aware local query expansion (CLQE) to mine reliable samples in relevant neighbors by exploiting camera variation as a strong constraint and assign these samples higher weights in overlap, further improving the reliability. Our CA-Jaccard distance is simple yet effective and can serve as a general distance metric for person re-ID methods with high reliability and low computational cost. Extensive experiments demonstrate the effectiveness of our method.

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cm chen960/ca-jaccard/caj/models/cm.py official repository ran MIT (permissive) · 10ba7332fd4a54eb · report
conv3x3 chen960/ca-jaccard/caj/models/resnet_ibn_a.py official repository ran · our draft was wrong MIT (permissive) · fac5364e2f53c6db · report
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Tasks

Person Re-IdentificationPerson RetrievalRe-RankingUnsupervised Person Re-IdentificationUnsupervised Vehicle Re-IdentificationVehicle Re-Identification

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Person Re-Identification MSMT17 CA-Jaccard Rank-1 86.2 #11 of 43 Archive leaderboard report
Person Re-Identification MSMT17 CA-Jaccard Rank-5 90.5 #11 of 43 Archive leaderboard report
Person Re-Identification MSMT17 CA-Jaccard mAP 74.1 #11 of 43 Archive leaderboard report
Person Re-Identification Market-1501 CA-Jaccard Rank-1 96.2 #19 of 135 Archive leaderboard report
Person Re-Identification Market-1501 CA-Jaccard Rank-5 98.1 #19 of 135 Archive leaderboard report
Person Re-Identification Market-1501 CA-Jaccard mAP 94.5 #19 of 135 Archive leaderboard report
Unsupervised Person Re-Identification MSMT17 CA-Jaccard Rank-1 75.1 #5 of 12 Archive leaderboard report
Unsupervised Person Re-Identification MSMT17 CA-Jaccard Rank-10 87.3 #5 of 12 Archive leaderboard report
Unsupervised Person Re-Identification MSMT17 CA-Jaccard Rank-5 84.3 #5 of 12 Archive leaderboard report
Unsupervised Person Re-Identification MSMT17 CA-Jaccard mAP 44.3 #5 of 12 Archive leaderboard report
Unsupervised Person Re-Identification Market-1501 CA-Jaccard MAP 86.1 #7 of 23 Archive leaderboard report
Unsupervised Person Re-Identification Market-1501 CA-Jaccard Rank-1 94.4 #7 of 23 Archive leaderboard report
Unsupervised Person Re-Identification Market-1501 CA-Jaccard Rank-10 98.7 #7 of 23 Archive leaderboard report
Unsupervised Person Re-Identification Market-1501 CA-Jaccard Rank-5 97.9 #7 of 23 Archive leaderboard report
Vehicle Re-Identification VeRi-776 CA-Jaccard Rank-1 97.6 #10 of 17 Archive leaderboard report
Vehicle Re-Identification VeRi-776 CA-Jaccard Rank-5 98.3 #10 of 17 Archive leaderboard report
Vehicle Re-Identification VeRi-776 CA-Jaccard mAP 81.4 #10 of 17 Archive leaderboard report

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