Multiscale Pixel-Level and Superpixel-Level Method for Hyperspectral Image Classification: Adaptive Attention and Parallel Multi-Hop Graph Convolution

Convolutional neural networks (CNNs) and graph convolutional networks (GCNs) have led to promising advancements in hyperspectral image (HSI) classification; however, traditional CNNs with fixed square convolution kernels are insufficiently flexible to handle irregular structures. Similarly, GCNs tha...

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Main Authors: Junru Yin, Xuan Liu, Ruixia Hou, Qiqiang Chen, Wei Huang, Aiguang Li, Peng Wang
Format: Article
Language:English
Published: MDPI AG 2023-08-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/15/17/4235
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author Junru Yin
Xuan Liu
Ruixia Hou
Qiqiang Chen
Wei Huang
Aiguang Li
Peng Wang
author_facet Junru Yin
Xuan Liu
Ruixia Hou
Qiqiang Chen
Wei Huang
Aiguang Li
Peng Wang
author_sort Junru Yin
collection DOAJ
description Convolutional neural networks (CNNs) and graph convolutional networks (GCNs) have led to promising advancements in hyperspectral image (HSI) classification; however, traditional CNNs with fixed square convolution kernels are insufficiently flexible to handle irregular structures. Similarly, GCNs that employ superpixel nodes instead of pixel nodes may overlook pixel-level features; both networks tend to extract features locally and cause loss of multilayer contextual semantic information during feature extraction due to the fixed kernel. To leverage the strengths of CNNs and GCNs, we propose a multiscale pixel-level and superpixel-level (MPAS)-based HSI classification method. The network consists of two sub-networks for extracting multi-level information of HSIs: a multi-scale hybrid spectral–spatial attention convolution branch (HSSAC) and a parallel multi-hop graph convolution branch (MGCN). HSSAC comprehensively captures pixel-level features with different kernel sizes through parallel multi-scale convolution and cross-path fusion to reduce the semantic information loss caused by fixed convolution kernels during feature extraction and learns adjustable weights from the adaptive spectral–spatial attention module (SSAM) to capture pixel-level feature correlations with less computation. MGCN can systematically aggregate multi-hop contextual information to better model HSIs’ spatial background structure using the relationship between parallel multi-hop graph transformation nodes. The proposed MPAS effectively captures multi-layer contextual semantic features by leveraging pixel-level and superpixel-level spectral–spatial information, which improves the performance of the HSI classification task while ensuring computational efficiency. Extensive evaluation experiments on three real-world HSI datasets demonstrate that MPAS outperforms other state-of-the-art networks, demonstrating its superior feature learning capabilities.
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spelling doaj.art-8b79e8db46564eb79a157fb6b09d27602023-11-19T08:46:21ZengMDPI AGRemote Sensing2072-42922023-08-011517423510.3390/rs15174235Multiscale Pixel-Level and Superpixel-Level Method for Hyperspectral Image Classification: Adaptive Attention and Parallel Multi-Hop Graph ConvolutionJunru Yin0Xuan Liu1Ruixia Hou2Qiqiang Chen3Wei Huang4Aiguang Li5Peng Wang6College of Computer and Communication Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, ChinaCollege of Computer and Communication Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, ChinaResearch Institute of Resource Information Techniques, CAF, Beijing 100091, ChinaCollege of Computer and Communication Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, ChinaCollege of Computer and Communication Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, ChinaSchool of Computer Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, ChinaCollege of Computer and Communication Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, ChinaConvolutional neural networks (CNNs) and graph convolutional networks (GCNs) have led to promising advancements in hyperspectral image (HSI) classification; however, traditional CNNs with fixed square convolution kernels are insufficiently flexible to handle irregular structures. Similarly, GCNs that employ superpixel nodes instead of pixel nodes may overlook pixel-level features; both networks tend to extract features locally and cause loss of multilayer contextual semantic information during feature extraction due to the fixed kernel. To leverage the strengths of CNNs and GCNs, we propose a multiscale pixel-level and superpixel-level (MPAS)-based HSI classification method. The network consists of two sub-networks for extracting multi-level information of HSIs: a multi-scale hybrid spectral–spatial attention convolution branch (HSSAC) and a parallel multi-hop graph convolution branch (MGCN). HSSAC comprehensively captures pixel-level features with different kernel sizes through parallel multi-scale convolution and cross-path fusion to reduce the semantic information loss caused by fixed convolution kernels during feature extraction and learns adjustable weights from the adaptive spectral–spatial attention module (SSAM) to capture pixel-level feature correlations with less computation. MGCN can systematically aggregate multi-hop contextual information to better model HSIs’ spatial background structure using the relationship between parallel multi-hop graph transformation nodes. The proposed MPAS effectively captures multi-layer contextual semantic features by leveraging pixel-level and superpixel-level spectral–spatial information, which improves the performance of the HSI classification task while ensuring computational efficiency. Extensive evaluation experiments on three real-world HSI datasets demonstrate that MPAS outperforms other state-of-the-art networks, demonstrating its superior feature learning capabilities.https://www.mdpi.com/2072-4292/15/17/4235convolutional neural networks (CNNs)graph convolutional networks (GCNs)hyperspectral image (HSI) classificationattention mechanismmulti-scale features
spellingShingle Junru Yin
Xuan Liu
Ruixia Hou
Qiqiang Chen
Wei Huang
Aiguang Li
Peng Wang
Multiscale Pixel-Level and Superpixel-Level Method for Hyperspectral Image Classification: Adaptive Attention and Parallel Multi-Hop Graph Convolution
Remote Sensing
convolutional neural networks (CNNs)
graph convolutional networks (GCNs)
hyperspectral image (HSI) classification
attention mechanism
multi-scale features
title Multiscale Pixel-Level and Superpixel-Level Method for Hyperspectral Image Classification: Adaptive Attention and Parallel Multi-Hop Graph Convolution
title_full Multiscale Pixel-Level and Superpixel-Level Method for Hyperspectral Image Classification: Adaptive Attention and Parallel Multi-Hop Graph Convolution
title_fullStr Multiscale Pixel-Level and Superpixel-Level Method for Hyperspectral Image Classification: Adaptive Attention and Parallel Multi-Hop Graph Convolution
title_full_unstemmed Multiscale Pixel-Level and Superpixel-Level Method for Hyperspectral Image Classification: Adaptive Attention and Parallel Multi-Hop Graph Convolution
title_short Multiscale Pixel-Level and Superpixel-Level Method for Hyperspectral Image Classification: Adaptive Attention and Parallel Multi-Hop Graph Convolution
title_sort multiscale pixel level and superpixel level method for hyperspectral image classification adaptive attention and parallel multi hop graph convolution
topic convolutional neural networks (CNNs)
graph convolutional networks (GCNs)
hyperspectral image (HSI) classification
attention mechanism
multi-scale features
url https://www.mdpi.com/2072-4292/15/17/4235
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