Papers › CBNet: A Composite Backbone Network Architecture for Object Detection

CBNet: A Composite Backbone Network Architecture for Object Detection

1 Jul 2021arXiv:2107.00420archive 2025-07-28

TingTing Liang, Xiaojie Chu, Yudong Liu, Yongtao Wang, Zhi Tang, Wei Chu, Jingdong Chen, Haibin Ling

Modern top-performing object detectors depend heavily on backbone networks, whose advances bring consistent performance gains through exploring more effective network structures. In this paper, we propose a novel and flexible backbone framework, namely CBNetV2, to construct high-performance detectors using existing open-sourced pre-trained backbones under the pre-training fine-tuning paradigm. In particular, CBNetV2 architecture groups multiple identical backbones, which are connected through composite connections. Specifically, it integrates the high- and low-level features of multiple backbone networks and gradually expands the receptive field to more efficiently perform object detection. We also propose a better training strategy with assistant supervision for CBNet-based detectors. Without additional pre-training of the composite backbone, CBNetV2 can be adapted to various backbones (CNN-based vs. Transformer-based) and head designs of most mainstream detectors (one-stage vs. two-stage, anchor-based vs. anchor-free-based). Experiments provide strong evidence that, compared with simply increasing the depth and width of the network, CBNetV2 introduces a more efficient, effective, and resource-friendly way to build high-performance backbone networks. Particularly, our Dual-Swin-L achieves 59.4% box AP and 51.6% mask AP on COCO test-dev under the single-model and single-scale testing protocol, which is significantly better than the state-of-the-art result (57.7% box AP and 50.2% mask AP) achieved by Swin-L, while the training schedule is reduced by 6×. With multi-scale testing, we push the current best single model result to a new record of 60.1% box AP and 52.3% mask AP without using extra training data. Code is available at https://github.com/VDIGPKU/CBNetV2.

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Tasks

Instance SegmentationObjectObject DetectionReal-Time Object Detectionobject-detection

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Instance Segmentation COCO minival CBNetV2 (Dual-Swin-L HTC, multi-scale) mask AP 51.8 #18 of 93 Archive leaderboard report
Instance Segmentation COCO minival CBNetV2 (Dual-Swin-L HTC, multi-scale) mask AP 51 #20 of 93 Archive leaderboard report
Instance Segmentation COCO test-dev CBNetV2 (EVA02, single-scale) AP50 80.3 #2 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev CBNetV2 (EVA02, single-scale) AP75 62.1 #2 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev CBNetV2 (EVA02, single-scale) APL 70.9 #2 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev CBNetV2 (EVA02, single-scale) APM 59.3 #2 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev CBNetV2 (EVA02, single-scale) APS 39.7 #2 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev CBNetV2 (EVA02, single-scale) mask AP 56.1 #2 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev CBNetV2 (Dual-Swin-L HTC, multi-scale) mask AP 52.3 #16 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev CBNetV2 (Dual-Swin-L HTC, single-scale) mask AP 51.6 #18 of 112 Archive leaderboard report
Object Detection COCO minival CBNetV2 (Dual-Swin-L HTC, multi-scale) box AP 59.6 #28 of 220 Archive leaderboard report
Object Detection COCO minival CBNetV2 (Dual-Swin-L HTC, multi-scale) box AP 59.1 #32 of 220 Archive leaderboard report
Object Detection COCO test-dev CBNetV2 (Dual-Swin-L HTC, multi-scale) box mAP 60.1 #30 of 225 Archive leaderboard report
Object Detection COCO test-dev CBNetV2 (Dual-Swin-L HTC, single-scale) box mAP 59.4 #32 of 225 Archive leaderboard report
Object Detection COCO-O CBNetV2 (Swin-L) Average mAP 39.0 #6 of 45 Archive leaderboard report
Object Detection COCO-O CBNetV2 (Swin-L) Effective Robustness 12.36 #6 of 45 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

Methods

1x1 ConvolutionConvolutionFPNHTCRPNRoIAlign

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