Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic Maps

Point symbols on a scanned topographic map (STM) provide crucial geographic information. However, point symbol recognition entails high complexity and uncertainty owing to the stickiness of map elements and singularity of symbol structures. Therefore, extracting point symbols from STMs is challengin...

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Main Authors: Wenjun Huang, Qun Sun, Anzhu Yu, Wenyue Guo, Qing Xu, Bowei Wen, Li Xu
Format: Article
Language:English
Published: MDPI AG 2023-03-01
Series:ISPRS International Journal of Geo-Information
Subjects:
Online Access:https://www.mdpi.com/2220-9964/12/3/128
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author Wenjun Huang
Qun Sun
Anzhu Yu
Wenyue Guo
Qing Xu
Bowei Wen
Li Xu
author_facet Wenjun Huang
Qun Sun
Anzhu Yu
Wenyue Guo
Qing Xu
Bowei Wen
Li Xu
author_sort Wenjun Huang
collection DOAJ
description Point symbols on a scanned topographic map (STM) provide crucial geographic information. However, point symbol recognition entails high complexity and uncertainty owing to the stickiness of map elements and singularity of symbol structures. Therefore, extracting point symbols from STMs is challenging. Currently, point symbol recognition is performed primarily through pattern recognition methods that have low accuracy and efficiency. To address this problem, we investigated the potential of a deep learning-based method for point symbol recognition and proposed a deep convolutional neural network (DCNN)-based model for this task. We created point symbol datasets from different sources for training and prediction models. Within this framework, atrous spatial pyramid pooling (ASPP) was adopted to handle the recognition difficulty owing to the differences between point symbols and natural objects. To increase the positioning accuracy, the k-means++ clustering method was used to generate anchor boxes that were more suitable for our point symbol datasets. Additionally, to improve the generalization ability of the model, we designed two data augmentation methods to adapt to symbol recognition. Experiments demonstrated that the deep learning method considerably improved the recognition accuracy and efficiency compared with classical algorithms. The introduction of ASPP in the object detection algorithm resulted in higher mean average precision and intersection over union values, indicating a higher recognition accuracy. It is also demonstrated that data augmentation methods can alleviate the cross-domain problem and improve the rotation robustness. This study contributes to the development of algorithms and the evaluation of geographic elements extracted from STMs.
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spelling doaj.art-1032e439613747c385c518470b44f8032023-11-17T11:28:27ZengMDPI AGISPRS International Journal of Geo-Information2220-99642023-03-0112312810.3390/ijgi12030128Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic MapsWenjun Huang0Qun Sun1Anzhu Yu2Wenyue Guo3Qing Xu4Bowei Wen5Li Xu6Institute of Geospatial Information, Information Engineering University, Zhengzhou 450001, ChinaInstitute of Geospatial Information, Information Engineering University, Zhengzhou 450001, ChinaInstitute of Geospatial Information, Information Engineering University, Zhengzhou 450001, ChinaInstitute of Geospatial Information, Information Engineering University, Zhengzhou 450001, ChinaInstitute of Geospatial Information, Information Engineering University, Zhengzhou 450001, ChinaInstitute of Geospatial Information, Information Engineering University, Zhengzhou 450001, ChinaInstitute of Geospatial Information, Information Engineering University, Zhengzhou 450001, ChinaPoint symbols on a scanned topographic map (STM) provide crucial geographic information. However, point symbol recognition entails high complexity and uncertainty owing to the stickiness of map elements and singularity of symbol structures. Therefore, extracting point symbols from STMs is challenging. Currently, point symbol recognition is performed primarily through pattern recognition methods that have low accuracy and efficiency. To address this problem, we investigated the potential of a deep learning-based method for point symbol recognition and proposed a deep convolutional neural network (DCNN)-based model for this task. We created point symbol datasets from different sources for training and prediction models. Within this framework, atrous spatial pyramid pooling (ASPP) was adopted to handle the recognition difficulty owing to the differences between point symbols and natural objects. To increase the positioning accuracy, the k-means++ clustering method was used to generate anchor boxes that were more suitable for our point symbol datasets. Additionally, to improve the generalization ability of the model, we designed two data augmentation methods to adapt to symbol recognition. Experiments demonstrated that the deep learning method considerably improved the recognition accuracy and efficiency compared with classical algorithms. The introduction of ASPP in the object detection algorithm resulted in higher mean average precision and intersection over union values, indicating a higher recognition accuracy. It is also demonstrated that data augmentation methods can alleviate the cross-domain problem and improve the rotation robustness. This study contributes to the development of algorithms and the evaluation of geographic elements extracted from STMs.https://www.mdpi.com/2220-9964/12/3/128point symbol recognitionscanned topographic mapdeep learninggeneralization abilitydata augmentation
spellingShingle Wenjun Huang
Qun Sun
Anzhu Yu
Wenyue Guo
Qing Xu
Bowei Wen
Li Xu
Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic Maps
ISPRS International Journal of Geo-Information
point symbol recognition
scanned topographic map
deep learning
generalization ability
data augmentation
title Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic Maps
title_full Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic Maps
title_fullStr Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic Maps
title_full_unstemmed Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic Maps
title_short Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic Maps
title_sort leveraging deep convolutional neural network for point symbol recognition in scanned topographic maps
topic point symbol recognition
scanned topographic map
deep learning
generalization ability
data augmentation
url https://www.mdpi.com/2220-9964/12/3/128
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