Contrastive Learning with Image Deformation and Refined NT-Xent Loss for Urban Morphology Discovery

The traditional paradigm for studying urban morphology involves the interpretation of Nolli maps, using methods such as morphometrics and visual neural networks. Previous studies on urban morphology discovery have always been based on raster analysis and have been limited to the central city area. R...

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Main Authors: Chunliang Hua, Daijun Chen, Mengyuan Niu, Lizhong Gao, Junyan Yang, Qiao Wang
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:ISPRS International Journal of Geo-Information
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Online Access:https://www.mdpi.com/2220-9964/14/5/196
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author Chunliang Hua
Daijun Chen
Mengyuan Niu
Lizhong Gao
Junyan Yang
Qiao Wang
author_facet Chunliang Hua
Daijun Chen
Mengyuan Niu
Lizhong Gao
Junyan Yang
Qiao Wang
author_sort Chunliang Hua
collection DOAJ
description The traditional paradigm for studying urban morphology involves the interpretation of Nolli maps, using methods such as morphometrics and visual neural networks. Previous studies on urban morphology discovery have always been based on raster analysis and have been limited to the central city area. Raster analysis can lead to fragmented forms, and focusing only on the central city area ignores many representative urban forms in the suburbs and towns. In this study, a vast and complex dataset was applied to the urban morphology discovery based on the administrative community or village boundary, and a new image deformation pipeline was proposed to enhance the morphological characteristics of building groups. This allows visual neural networks to focus on extracting the morphological characteristics of building groups. Additionally, the research on urban morphology often uses unsupervised learning, which means that the learning process is difficult to control. Therefore, we refined the NT-Xent loss so that it can integrate morphological indicators. This improvement allows the visual neural network to “recognize” the similarity of samples during optimization. By defining the similarity, we can guide the network to bring samples closer or move them farther apart based on certain morphological indicators. Three Chinese cities were used for our testing. Representative urban types were identified, particularly some types located at the urban fringe. The data analysis demonstrated the effectiveness of our image deformation pipeline and loss function, and the sociological analysis illustrated the unique urban functions of these urban types.
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id doaj-art-5047ebdd83f048ad80bd9c1a395cf30c
institution Kabale University
issn 2220-9964
language English
publishDate 2025-05-01
publisher MDPI AG
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series ISPRS International Journal of Geo-Information
spelling doaj-art-5047ebdd83f048ad80bd9c1a395cf30c2025-08-20T03:47:54ZengMDPI AGISPRS International Journal of Geo-Information2220-99642025-05-0114519610.3390/ijgi14050196Contrastive Learning with Image Deformation and Refined NT-Xent Loss for Urban Morphology DiscoveryChunliang Hua0Daijun Chen1Mengyuan Niu2Lizhong Gao3Junyan Yang4Qiao Wang5School of Information Science and Engineering, Southeast University, Nanjing 211189, ChinaSchool of Architecture, Southeast University, Nanjing 210096, ChinaSchool of Information Science and Engineering, Southeast University, Nanjing 211189, ChinaSchool of Information Science and Engineering, Southeast University, Nanjing 211189, ChinaSchool of Architecture, Southeast University, Nanjing 210096, ChinaSchool of Information Science and Engineering, Southeast University, Nanjing 211189, ChinaThe traditional paradigm for studying urban morphology involves the interpretation of Nolli maps, using methods such as morphometrics and visual neural networks. Previous studies on urban morphology discovery have always been based on raster analysis and have been limited to the central city area. Raster analysis can lead to fragmented forms, and focusing only on the central city area ignores many representative urban forms in the suburbs and towns. In this study, a vast and complex dataset was applied to the urban morphology discovery based on the administrative community or village boundary, and a new image deformation pipeline was proposed to enhance the morphological characteristics of building groups. This allows visual neural networks to focus on extracting the morphological characteristics of building groups. Additionally, the research on urban morphology often uses unsupervised learning, which means that the learning process is difficult to control. Therefore, we refined the NT-Xent loss so that it can integrate morphological indicators. This improvement allows the visual neural network to “recognize” the similarity of samples during optimization. By defining the similarity, we can guide the network to bring samples closer or move them farther apart based on certain morphological indicators. Three Chinese cities were used for our testing. Representative urban types were identified, particularly some types located at the urban fringe. The data analysis demonstrated the effectiveness of our image deformation pipeline and loss function, and the sociological analysis illustrated the unique urban functions of these urban types.https://www.mdpi.com/2220-9964/14/5/196urban formNolli mapNT-Xent lossunsupervised learningimage deformationcontrastive learning
spellingShingle Chunliang Hua
Daijun Chen
Mengyuan Niu
Lizhong Gao
Junyan Yang
Qiao Wang
Contrastive Learning with Image Deformation and Refined NT-Xent Loss for Urban Morphology Discovery
ISPRS International Journal of Geo-Information
urban form
Nolli map
NT-Xent loss
unsupervised learning
image deformation
contrastive learning
title Contrastive Learning with Image Deformation and Refined NT-Xent Loss for Urban Morphology Discovery
title_full Contrastive Learning with Image Deformation and Refined NT-Xent Loss for Urban Morphology Discovery
title_fullStr Contrastive Learning with Image Deformation and Refined NT-Xent Loss for Urban Morphology Discovery
title_full_unstemmed Contrastive Learning with Image Deformation and Refined NT-Xent Loss for Urban Morphology Discovery
title_short Contrastive Learning with Image Deformation and Refined NT-Xent Loss for Urban Morphology Discovery
title_sort contrastive learning with image deformation and refined nt xent loss for urban morphology discovery
topic urban form
Nolli map
NT-Xent loss
unsupervised learning
image deformation
contrastive learning
url https://www.mdpi.com/2220-9964/14/5/196
work_keys_str_mv AT chunlianghua contrastivelearningwithimagedeformationandrefinedntxentlossforurbanmorphologydiscovery
AT daijunchen contrastivelearningwithimagedeformationandrefinedntxentlossforurbanmorphologydiscovery
AT mengyuanniu contrastivelearningwithimagedeformationandrefinedntxentlossforurbanmorphologydiscovery
AT lizhonggao contrastivelearningwithimagedeformationandrefinedntxentlossforurbanmorphologydiscovery
AT junyanyang contrastivelearningwithimagedeformationandrefinedntxentlossforurbanmorphologydiscovery
AT qiaowang contrastivelearningwithimagedeformationandrefinedntxentlossforurbanmorphologydiscovery