A Lightweight, Arbitrary-oriented SAR Ship Detector via Feature Map-based Knowledge Distillation
-
摘要: 基于有向边界框的合成孔径雷达(SAR)舰船目标检测器能输出精准的边界框,但仍存在模型计算复杂度高、推理速度慢、存储消耗大等问题,导致其难以在星载平台上部署。基于此该文提出了结合特征图和检测头分支知识蒸馏的无锚框轻量化旋转检测方法。首先,结合目标的长宽比和方向角信息提出改进高斯核,使生成的热度图能更好地刻画目标形状。然后在检测器预测头部引入前景区域增强分支,使网络更关注前景特征且抑制背景杂波的干扰。在训练轻量化网络时,将像素点间的相似度构建为热度图蒸馏知识。为解决特征蒸馏中正负样本不平衡问题,将前景注意力区域作为掩模引导网络蒸馏与目标相关的特征。另外,该文提出全局语义模块对像素进行上下文信息建模,能够结合背景知识加强目标精确表征。基于HRSID数据集的实验结果表明所提方法在模型参数仅有9.07 M的轻量化条件下,mAP能达到80.71%,且检测帧率满足实时应用需求。
-
关键词:
- 合成孔径雷达舰船目标检测 /
- 轻量化旋转框检测 /
- 改进高斯核 /
- 前景区域增强 /
- 知识蒸馏
Abstract: In the Synthetic Aperture Radar (SAR) ship target detection task, the targets have a large aspect ratio and dense distribution, and they are arranged in arbitrary directions. The oriented bounding box-based detection methods can output accurate detection results. However, these methods are strongly restricted by high computational complexity, slow inference speed, and large storage consumption, which complicate their deployment on space-borne platforms. To solve the above issues, a lightweight oriented anchor-free-based detection method is proposed by combining feature map and prediction head knowledge distillation. First, we propose an improved Gaussian kernel based on the aspect ratio and angle information so that the generated heatmaps can better describe the shape of the targets. Second, the foreground region enhancement branch is introduced to make the network focus more on foreground features while suppressing the background interference. When training the lightweight student network, the similarity between pixels is treated as transferred knowledge in heatmap distillation. To tackle the imbalance between positive and negative samples in feature distillation, the foreground attention region is applied as a mask to guide the feature distillation process. In addition, a global semantic module is proposed to model the contextual information around pixels, and the background knowledge is combined to further strengthen the feature representation. Experimental results based on HRSID show that our method can achieve 80.71% mAP with only 9.07 M model parameters, and the detection frame rate meets the needs of real-time applications. -
表 1 HRSID数据集上的消融实验
Table 1. Ablation experiments on HRSID dataset
基线 旋转高斯核 前景注意力引导 准确率 召回率 平均精度 F1分数 √ 0.8540 0.7234 0.7833 0.7759 √ √ 0.8591 0.7579 0.7927 0.8053 √ √ 0.8448 0.7746 0.8033 0.8082 √ √ √ 0.8877 0.7543 0.8120 0.8156 表 2 教师和学生检测网络的性能比较
Table 2. Performance comparison of teacher and student detection network
检测网络 骨干网络 参数量(M) 浮点计算量(G) 精度 教师网络 HRNet32 30.53 104.06 0.8120 未蒸馏学生网络 HRNet16 9.07 59.05 0.7402 蒸馏后学生网络 HRNet16 9.07 59.05 0.7596 表 3 不同蒸馏方法在近岸和远海场景下的检测性能比较
Table 3. Detection performance comparison of different distillation methods under inshore and offsihore scenes
蒸馏方法 近岸 远海 P R F1 AP P R F1 AP Baseline 0.6241 0.5231 0.5691 0.4819 0.9370 0.9282 0.9326 0.9190 Mimic fea 0.6801 0.4924 0.5712 0.4912 0.9382 0.9279 0.9330 0.9194 L2热度图 0.6539 0.5153 0.5764 0.5061 0.9440 0.9321 0.9380 0.9228 改进热度图蒸馏 0.6665 0.5685 0.6136 0.5389 0.9512 0.9321 0.9416 0.9269 AT fea+改进热度图蒸馏 0.7114 0.5491 0.6198 0.5454 0.9533 0.9347 0.9439 0.9272 改进特征+热度图蒸馏 0.7473 0.5664 0.6443 0.5778 0.9571 0.9279 0.9422 0.9255 表 4 典型旋转检测器上的性能比较
Table 4. Performance comparison on typical oriented detectors
检测器 准确率 召回率 F1值 平均精度 参数量 帧率 RoI Transformer 0.8524 0.7198 0.7805 0.7681 55.26 11.34 YOLOv3-R 0.8225 0.6531 0.7281 0.6907 59.68 9.13 BBAV 0.8462 0.7332 0.7857 0.7720 71.83 19.08 Oriented-RCNN 0.8369 0.7271 0.7781 0.7582 41.82 15.13 DAL 0.8517 0.7603 0.8034 0.7896 36.34 8.06 CenterNet-R 0.8628 0.7381 0.7956 0.7319 34.04 18.30 RetinaNet-R 0.8301 0.6638 0.7377 0.7070 32.33 16.10 本文方法 0.8475 0.7736 0.8089 0.8071 9.07 28.76 -
[1] DU Lan, DAI Hui, WANG Yan, et al. Target discrimination based on weakly supervised learning for high-resolution SAR images in complex scenes[J]. IEEE Transactions on Geoscience and Remote Sensing, 2020, 58(1): 461–472. doi: 10.1109/TGRS.2019.2937175 [2] CHEN Jianlai, ZHANG Junchao, JIN Yanghao, et al. Real-time processing of spaceborne SAR data with nonlinear trajectory based on variable PRF[J]. IEEE Transactions on Geoscience and Remote Sensing, 2022, 60: 5205212. doi: 10.1109/TGRS.2021.3067945 [3] GAO Gui, LIU Li, ZHAO Lingjun, et al. An adaptive and fast CFAR algorithm based on automatic censoring for target detection in high-resolution SAR images[J]. IEEE Transactions on Geoscience and Remote Sensing, 2009, 47(6): 1685–1697. doi: 10.1109/TGRS.2008.2006504 [4] CRISP D J. The state-of-the-art in ship detection in synthetic aperture radar imagery[R]. DSTO-RR-0272, 2004. [5] 李健伟, 曲长文, 彭书娟, 等. 基于卷积神经网络的SAR图像舰船目标检测[J]. 系统工程与电子技术, 2018, 40(9): 1953–1959. doi: 10.3969/j.issn.1001-506X.2018.09.09LI Jianwei, QU Changwen, PENG Shujuan, et al. Ship detection in SAR images based on convolutional neural network[J]. Systems Engineering and Electronics, 2018, 40(9): 1953–1959. doi: 10.3969/j.issn.1001-506X.2018.09.09 [6] REN Shaoqing, HE Kaiming, GIRSHICK R, et al. Faster R-CNN: Towards real-time object detection with region proposal networks[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence, 2017, 39(6): 1137–1149. doi: 10.1109/TPAMI.2016.2577031 [7] ZHANG Xiaohan, WANG Haipeng, XU Congan, et al. A lightweight feature optimizing network for ship detection in SAR image[J]. IEEE Access, 2019, 7: 141662–141678. doi: 10.1109/ACCESS.2019.2943241 [8] LIU Wei, ANGUELOV D, ERHAN D, et al. SSD: Single shot MultiBox detector[C]. The 14th European Conference on Computer Vision, Amsterdam, The Netherlands, 2016: 21–37. [9] 张晓玲, 张天文, 师君, 等. 基于深度分离卷积神经网络的高速高精度SAR舰船检测[J]. 雷达学报, 2019, 8(6): 841–851. doi: 10.12000/JR19111ZHANG Xiaoling, ZHANG Tianwen, SHI Jun, et al. High-speed and high-accurate SAR ship detection based on a depthwise separable convolution neural network[J]. Journal of Radars, 2019, 8(6): 841–851. doi: 10.12000/JR19111 [10] REDMON J and FARHADI A. YOLOv3: An incremental improvement[J]. arXiv: 1804.02767, 2018. [11] GAO S, LIU Jianming, MIAO Yuhao, et al. A high-effective implementation of ship detector for SAR images[J]. IEEE Geoscience and Remote Sensing Letters, 2022, 19: 4019005. doi: 10.1109/LGRS.2021.3115121 [12] ZHU Mingming, HU Guoping, ZHOU Hao, et al. H2Det: A high-speed and high-accurate ship detector in SAR images[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2021, 14: 12455–12466. doi: 10.1109/JSTARS.2021.313116 [13] FU Jiamei, SUN Xian, WANG Zhirui, et al. An anchor-free method based on feature balancing and refinement network for multiscale ship detection in SAR images[J]. IEEE Transactions on Geoscience and Remote Sensing, 2021, 59(2): 1331–1344. doi: 10.1109/TGRS.2020.3005151 [14] TIAN Zhi, SHEN Chunhua, CHEN Hao, et al. FCOS: Fully convolutional one-stage object detection[C]. 2019 IEEE/CVF International Conference on Computer Vision (ICCV), Seoul, Korea, 2020: 9626–9635. [15] 孙忠镇, 戴牧宸, 雷禹, 等. 基于级联网络的复杂大场景SAR图像舰船目标快速检测[J]. 信号处理, 2021, 37(6): 941–951. doi: 10.16798/j.issn.1003-0530.2021.06.005SUN Zhongzhen, DAI Muchen, LEI Yu, et al. Fast detection of ship targets for complex large-scene SAR images based on a cascade network[J]. Journal of Signal Processing, 2021, 37(6): 941–951. doi: 10.16798/j.issn.1003-0530.2021.06.005 [16] GUO Haoyuan, YANG Xi, WANG Nannan, et al. A CenterNet++ model for ship detection in SAR images[J]. Pattern Recognition, 2021, 112: 107787. doi: 10.1016/j.patcog.2020.107787 [17] ZHOU Xingyi, WANG Dequan, and KRHENBÜHL P. Objects as points[EB/OL]. http://arxiv.org/abs/1904.07850, 2019. [18] AN Quanzhi, PAN Zongxu, LIU Lei, et al. DRBox-v2: An improved detector with rotatable boxes for target detection in SAR images[J]. IEEE Transactions on Geoscience and Remote Sensing, 2019, 57(11): 8333–8349. doi: 10.1109/TGRS.2019.2920534 [19] YANG Rong, PAN Zhenru, JIA Xiaoxue, et al. A novel CNN-based detector for ship detection based on rotatable bounding box in SAR images[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2021, 14: 1938–1958. doi: 10.1109/JSTARS.2021.3049851 [20] LIN Tsung-Yi, GOYAL P, GIRSHICK R, et al. Focal loss for dense object detection[C]. 2017 IEEE International Conference on Computer Vision (ICCV), Venice, Italy, 2017: 2999–3007. [21] 徐英, 谷雨, 彭冬亮, 等. 面向合成孔径雷达图像任意方向舰船检测的改进YOLOv3模型[J]. 兵工学报, 2021, 42(8): 1698–1707. doi: 10.3969/j.issn.1000-1093.2021.08.014XU Ying, GU Yu, PENG Dongliang, et al. An improved YOLOv3 model for arbitrary-oriented ship detection in SAR image[J]. Acta Armamentarii, 2021, 42(8): 1698–1707. doi: 10.3969/j.issn.1000-1093.2021.08.014 [22] FU Kun, FU Jiamei, WANG Zhihui, et al. Scattering-keypoint-guided network for oriented ship detection in high-resolution and large-scale SAR images[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2021, 14: 11162–11178. doi: 10.1109/JSTARS.2021.3109469 [23] XU Yongchao, FU Mingtao, WANG Qimeng, et al. Gliding vertex on the horizontal bounding box for multi-oriented object detection[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence, 2021, 43(4): 1452–1459. doi: 10.1109/TPAMI.2020.2974745 [24] WANG Jingdong, SUN Ke, CHENG Tianheng, et al. Deep high-resolution representation learning for visual recognition[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence, 2021, 43(10): 3349–3364. doi: 10.1109/TPAMI.2020.2983686 [25] ZHANG Linfeng and MA Kaisheng. Improve object detection with feature-based knowledge distillation: Towards accurate and efficient detectors[C]. International Conference on Learning Representations, 2020. [26] CAO Yue, XU Jiarui, LIN Stephen, et al. GCNet: Non-local networks meet squeeze-excitation networks and beyond[C]. The IEEE/CVF International Conference on Computer Vision Workshop, Seoul, Korea, 2019: 1971–1980. [27] WEI Shunjun, ZENG Xiangfeng, QU Qizhe, et al. HRSID: A high-resolution SAR images dataset for ship detection and instance segmentation[J]. IEEE Access, 2020, 8: 120234–120254. doi: 10.1109/ACCESS.2020.3005861 [28] ZAGORUYKO S and KOMODAKIS N. Paying more attention to attention: Improving the performance of convolutional neural networks via attention transfer[EB/OL]. http://arxiv.org/abs/1612.03928, 2016. [29] ROMERO A, BALLAS N, KAHOU S E, et al. FitNets: Hints for thin deep nets[EB/OL]. http://arxiv.org/abs/1412.6550, 2014. [30] YI Jingru, WU Pengxiang, LIU Bo, et al. Oriented object detection in aerial images with box boundary-aware vectors[C]. The IEEE Winter Conference on Applications of Computer Vision, Waikoloa, USA, 2021: 2149–2158. [31] MING Qi, ZHOU Zhiqiang, MIAO Lingjuan, et al. Dynamic anchor learning for arbitrary-oriented object detection[EB/OL]. http://arxiv.org/abs/2012.04150, 2020. [32] DING Jian, XUE Nan, LONG Yang, et al. Learning RoI transformer for oriented object detection in aerial images[C]. The IEEE/CVF Conference on Computer Vision and Pattern Recognition, Long Beach, USA, 2019: 2844–2853. [33] XIE Xingxing, CHENG Gong, WANG Jiabao, et al. Oriented R-CNN for object detection[C]. The IEEE/CVF International Conference on Computer Vision. 2021: 3520–3529. [34] 孙显, 王智睿, 孙元睿, 等. AIR-SARShip-1.0: 高分辨率SAR舰船检测数据集[J]. 雷达学报, 2019, 8(6): 852–862. doi: 10.12000/JR19097SUN Xian, WANG Zhirui, SUN Yuanrui, et al. AIR-SARShip-1.0: High-resolution SAR ship detection dataset[J]. Journal of Radars, 2019, 8(6): 852–862. doi: 10.12000/JR19097 期刊类型引用(23)
1. 肖敏睿,王巍,尤明懿,陈新. 存在时频统误差条件下的联合时频差定位与观测站航迹优化方法. 信号处理. 2025(01): 150-160 . 百度学术
2. Xin Yang,Hongming Liu,Xiaoke Wang,Wen Yu,Jingqiu Liu,Sipei Zhang. A Fusion Localization Method Based on Target Measurement Error Feature Complementarity and Its Application. Journal of Beijing Institute of Technology. 2024(01): 75-88 . 必应学术
3. 任洋,姚金杰,赵昶淳,邹宇,薛晓东. 卫星导航多干扰源直接定位方法. 计算机测量与控制. 2024(04): 159-165+173 . 百度学术
4. 罗军,张顺生. 联合自适应LASSO与块稀疏贝叶斯直接定位方法. 雷达科学与技术. 2024(03): 265-274 . 百度学术
5. 万鹏武,李文杰,彭康. 混合信道下基于到达时间的快速直接定位算法. 西安邮电大学学报. 2024(02): 20-26 . 百度学术
6. Dandan Li,Deyi Wang,Hao Huan. LFM Radar Source Passive Localization Algorithm Based on Range Migration. Journal of Beijing Institute of Technology. 2024(02): 130-140 . 必应学术
7. 李俊霞,王欣,黄高见,徐勇军,郝万明,朱政宇,李兴旺. 无源定位技术发展及其展望. 无线电工程. 2024(08): 1825-1846 . 百度学术
8. 陈梁栋,黄知涛,王翔,吴癸周. 基于角速度信息先验的固定无源单站直接定位方法. 电子学报. 2024(07): 2190-2200 . 百度学术
9. 任洋,姚金杰,赵昶淳. 一种自适应网格细化的卫星干扰源定位方法. 火力与指挥控制. 2024(08): 152-158+165 . 百度学术
10. 张炜,杨秋,李昊. 一种分布式一体化传感器异步纯方位跟踪管理方法. 指挥控制与仿真. 2024(06): 43-48 . 百度学术
11. 王雨琦,吴楠,张旭,刘丹,王海强,韩笑冬,仲小清,王宁远. 多星分布式无源相干定位方法. 中国空间科学技术. 2023(01): 63-68 . 百度学术
12. 陈志坤,翁一鸣,彭冬亮,吴美婵. 基于VEPPSO-EXTRA混合算法的分布式直接定位技术. 电子与信息学报. 2023(02): 664-671 . 百度学术
13. 罗迪,尹灿斌,李智. 双星对地面未知辐射源直接定位方法研究. 指挥控制与仿真. 2023(01): 136-143 . 百度学术
14. 刘云天,史鑫磊. 多基站非圆信号直接定位:降维PM与泰勒补偿. 太赫兹科学与电子信息学报. 2023(06): 725-733 . 百度学术
15. 夏楠,高丹阳,邢宝辉,王亚宁. 基于外辐射源的空中目标直接定位算法. 通信学报. 2023(06): 117-124 . 百度学术
16. 唐元春,陈端云,夏炳森. 基于传播算子的卫星导航系统干扰源直接定位方法. 太赫兹科学与电子信息学报. 2023(08): 985-991 . 百度学术
17. 张怡霄,王怀习,姚云龙,常超,康凯. 基于聚类与霍夫变换的同型雷达多目标定位算法. 电讯技术. 2023(12): 1885-1893 . 百度学术
18. 刘清,谢坚,王伶,王秋红,张兆林. 卫星导航欺骗式干扰源高精度直接定位方法. 电子学报. 2022(05): 1117-1122 . 百度学术
19. 韦卓. 基于单站干涉仪测向法的未知辐射源定位技术. 舰船电子工程. 2022(07): 159-161 . 百度学术
20. 王裕旗,孙光才,邢孟道,张子敬. 合成孔径无源定位性能分析与参数设计. 电子与信息学报. 2022(09): 3155-3162 . 百度学术
21. 刘振,苏晓龙,刘天鹏,彭勃,陈鑫,刘永祥. 基于矩阵差分的远场和近场混合源定位方法. 雷达学报. 2021(03): 432-442 . 本站查看
22. 金峥嵘,王洁,陈丹彤,赵翼,朱秋明,段洪涛. 基于频谱测绘的辐射源定位. 通信技术. 2021(12): 2644-2649 . 百度学术
23. 张国鑫,易伟,孔令讲. 基于1比特量化的大规模MIMO雷达系统直接定位算法. 雷达学报. 2021(06): 970-981 . 本站查看
其他类型引用(22)
-