Multi-Level Alignment Network for Cross-Domain Ship Detection

Ship detection is an important research topic in the field of remote sensing. Compared with optical detection methods, Synthetic Aperture Radar (SAR) ship detection can penetrate clouds to detect hidden ships in all-day and all-weather. Currently, the state-of-the-art methods exploit convolutional n...

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Main Authors: Chujie Xu, Xiangtao Zheng, Xiaoqiang Lu
Format: Article
Language:English
Published: MDPI AG 2022-05-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/14/10/2389
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author Chujie Xu
Xiangtao Zheng
Xiaoqiang Lu
author_facet Chujie Xu
Xiangtao Zheng
Xiaoqiang Lu
author_sort Chujie Xu
collection DOAJ
description Ship detection is an important research topic in the field of remote sensing. Compared with optical detection methods, Synthetic Aperture Radar (SAR) ship detection can penetrate clouds to detect hidden ships in all-day and all-weather. Currently, the state-of-the-art methods exploit convolutional neural networks to train ship detectors, which require a considerable labeled dataset. However, it is difficult to label the SAR images because of expensive labor and well-trained experts. To address the above limitations, this paper explores a cross-domain ship detection task, which adapts the detector from labeled optical images to unlabeled SAR images. There is a significant visual difference between SAR images and optical images. To achieve cross-domain detection, the multi-level alignment network, which includes image-level, convolution-level, and instance-level, is proposed to reduce the large domain shift. First, image-level alignment exploits generative adversarial networks to generate SAR images from the optical images. Then, the generated SAR images and the real SAR images are used to train the detector. To further minimize domain distribution shift, the detector integrates convolution-level alignment and instance-level alignment. Convolution-level alignment trains the domain classifier on each activation of the convolutional features, which minimizes the domain distance to learn domain-invariant features. Instance-level alignment reduces domain distribution shift on the features extracted from the region proposals. The entire multi-level alignment network is trained end-to-end and its effectiveness is proved on multiple cross-domain ship detection datasets.
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spelling doaj.art-9c08f7334c754b4b84f4502b58c5f72f2023-11-23T12:55:24ZengMDPI AGRemote Sensing2072-42922022-05-011410238910.3390/rs14102389Multi-Level Alignment Network for Cross-Domain Ship DetectionChujie Xu0Xiangtao Zheng1Xiaoqiang Lu2Key Laboratory of Spectral Imaging Technology CAS, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, ChinaKey Laboratory of Spectral Imaging Technology CAS, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, ChinaKey Laboratory of Spectral Imaging Technology CAS, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, ChinaShip detection is an important research topic in the field of remote sensing. Compared with optical detection methods, Synthetic Aperture Radar (SAR) ship detection can penetrate clouds to detect hidden ships in all-day and all-weather. Currently, the state-of-the-art methods exploit convolutional neural networks to train ship detectors, which require a considerable labeled dataset. However, it is difficult to label the SAR images because of expensive labor and well-trained experts. To address the above limitations, this paper explores a cross-domain ship detection task, which adapts the detector from labeled optical images to unlabeled SAR images. There is a significant visual difference between SAR images and optical images. To achieve cross-domain detection, the multi-level alignment network, which includes image-level, convolution-level, and instance-level, is proposed to reduce the large domain shift. First, image-level alignment exploits generative adversarial networks to generate SAR images from the optical images. Then, the generated SAR images and the real SAR images are used to train the detector. To further minimize domain distribution shift, the detector integrates convolution-level alignment and instance-level alignment. Convolution-level alignment trains the domain classifier on each activation of the convolutional features, which minimizes the domain distance to learn domain-invariant features. Instance-level alignment reduces domain distribution shift on the features extracted from the region proposals. The entire multi-level alignment network is trained end-to-end and its effectiveness is proved on multiple cross-domain ship detection datasets.https://www.mdpi.com/2072-4292/14/10/2389ship detectiondomain adaptationconvolutional neural networksynthetic aperture radar
spellingShingle Chujie Xu
Xiangtao Zheng
Xiaoqiang Lu
Multi-Level Alignment Network for Cross-Domain Ship Detection
Remote Sensing
ship detection
domain adaptation
convolutional neural network
synthetic aperture radar
title Multi-Level Alignment Network for Cross-Domain Ship Detection
title_full Multi-Level Alignment Network for Cross-Domain Ship Detection
title_fullStr Multi-Level Alignment Network for Cross-Domain Ship Detection
title_full_unstemmed Multi-Level Alignment Network for Cross-Domain Ship Detection
title_short Multi-Level Alignment Network for Cross-Domain Ship Detection
title_sort multi level alignment network for cross domain ship detection
topic ship detection
domain adaptation
convolutional neural network
synthetic aperture radar
url https://www.mdpi.com/2072-4292/14/10/2389
work_keys_str_mv AT chujiexu multilevelalignmentnetworkforcrossdomainshipdetection
AT xiangtaozheng multilevelalignmentnetworkforcrossdomainshipdetection
AT xiaoqianglu multilevelalignmentnetworkforcrossdomainshipdetection