Chengjun Wang

Dr. Chengjun Wang


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 July 2022 in IEEE Transactions on Geoscience and Remote Sensing
Verified
Journal Article
Closed access
CWChengjun Wang
Chengjun Wang
MXMiaozhong Xu
Miaozhong Xu
Yonghua JiangYonghua Jiang
Yonghua Jiang
GZGuo Zhang
Guo Zhang
CHCui Hao
Cui Hao
DLDa Li
Da Li
Hyperspectral remote sensing images (HSIs) have been applied in urban planning, environmental monitoring, and other fields. However, they are susceptible to noise interference, such as Gaussian noise, stripe, and mixed noises, from various factors in the imaging process, which greatly limits their applications. Although previous efforts to improve HSI quality have achieved remarkable results, there are still many challenges to be solved. To avoid the poor generalization ability and improve the stripe removal performance of the network in real scenarios, in this article, we proposed a novel deep learning model (Translution-SNet) for HSI stripe noise removal based on a semisupervised training strategy that applies a convolution and transformer for feature extraction. Moreover, we used an unbiased estimation method to calculate the loss function of the unsupervised part from noisy data without a clean image. The semisupervised method improved the ability of Translution-SNet to deal with various complex stripe noises during stripe removal and strengthened its robustness and generalization ability. Our experimental results showed that Translution-SNet could robustly handle stripe noise of images with different loads and achieve satisfactory results, proving its feasibility and effectiveness. In addition, Translution-SNet showed good generalization ability.

15 May 2023 in IEEE Transactions on Geoscience and Remote Sensing
Verified
Journal Article
Closed access
GDGuohui Deng
Guohui Deng
ZWZhaocong Wu
Zhaocong Wu
MXMiaozhong Xu
Miaozhong Xu
CWChengjun Wang
Chengjun Wang
ZWZhiye Wang
Zhiye Wang
ZLZhongyuan Lu
Zhongyuan Lu
Semantic segmentation is a key means for understanding very-high resolution (VHR) aerial imagery. With the explosive development of deep learning, deep learning methods are being applied to the segmentation of VHR images, with convolutional neural networks (CNNs) as the basic framework. However, owing to the highly complex details present in VHR images and the high spatial dependence of geographical objects, CNN-based methods are inadequate. This is because the inherent locality of CNNs limits the size of the receptive field, thus limiting the ability to obtain long-range context information. To solve this problem, in this paper, we propose a transformer-based novel deep learning model called crisscross-global vision transformers (CGVT). CGVT exploits the transformer’s inherent ability to obtain long-range context information to solve the restricted receptive field problem. Specifically, we redesign the self-attention mechanism in the transformer and call it crisscross-global attention. It consists of two parts: crisscross transformer encoder block (CC-TEB) and global squeeze transformer encoder block (GS-TEB). CC-TEB overcomes the limitation of the traditional self-attention design (specifically, difficulty applying it to VHR aerial image segmentation) and further increases the local feature representation ability of the model. GS-TEB increases the global feature representation ability of the model. The results of experiments conducted on the popular ISPRS Vaihingen, IEEE GRSS Data Fusion Contest Zeebrugge, and LoveDA Semantic Segmentation Challenge datasets verify the effectiveness and superiority of our proposed method. Specifically, it achieved state-of-the-art performance on both Zeebrugge and LoveDA datasets, and is currently ranked second in Vaihingen dataset.

1 July 2024 in Nonlinear Dynamics
Verified
Journal Article
Closed access
PDF file
YPYuexi Peng
Yuexi Peng
WXWei Xu
Wei Xu
FPFatemeh Parastesh
Fatemeh Parastesh
ZLZhijun Li
Zhijun Li
CLChunlai Li
Chunlai Li
CWChengjun Wang
Chengjun Wang

27 December 2021 in IEEE Transactions on Geoscience and Remote Sensing
Verified
Journal Article
Closed access
CWChengjun Wang
Chengjun Wang
MXMiaozhong Xu
Miaozhong Xu
Yonghua JiangYonghua Jiang
Yonghua Jiang
GDGuohui Deng
Guohui Deng
ZLZhongyuan Lu
Zhongyuan Lu
CHCui Hao
Cui Hao
Remote sensing images, especially hyperspectral images (HSIs), are extremely vulnerable to random noise and stripe noise. As a key aspect of HSI data quality improvement, stripe noise removal has always been a pervasive issue in remote sensing image processing. Convolutional neural networks have been applied for HSI data destriping. However, the existing methods lose the stripe-free component of the original image to a certain extent. These models also ignore the global spatial context of images and the correlation between spatial information and spectral information. Therefore, we propose a novel destriping convolutional network to overcome the problems with the existing methods. Octave convolution is used to extract cross-frequency features, and separate and compress the low-frequency information of the images, while dilation convolution (Dila-Conv) is used to reduce the amount of required calculation and also preserve the key image information. In addition, Dila-Conv can expand the receptive field to obtain multiscale features. Finally, a cross-channel enhanced spatial–spectral feature fusion module is used to acquire and integrate spatial context information and interchannel dependencies on a global scale as auxiliary information so that the network model can learn and pay attention to key feature information, specifically, “what to look for” and “where to look at,” which can facilitate the distinction between stripe and stripe-free components. Experimental results obtained using multiple datasets demonstrated that the proposed method can outperform the existing comparable methods and can produce satisfactory results in terms of visual effects and quantitative evaluation.

18 July 2024 in Remote Sensing
Verified
Journal Article
Open access
PDF file
WXWeiming Xu
Weiming Xu
JWJuan Wang
Juan Wang
CWChengjun Wang
Chengjun Wang
ZLZiwei Li
Ziwei Li
JZJianchang Zhang
Jianchang Zhang
SWSheng Wu
Sheng Wu
The accurate extraction of agricultural parcels from remote sensing images is crucial for advanced agricultural management and monitoring systems. Existing methods primarily emphasize regional accuracy over boundary quality, often resulting in fragmented outputs due to uniform crop types, diverse agricultural practices, and environmental variations. To address these issues, this paper proposes DSTBA-Net, an end-to-end encoder–decoder architecture. Initially, we introduce a Dual-Stream Feature Extraction (DSFE) mechanism within the encoder, which consists of Residual Blocks and Boundary Feature Guidance (BFG) to separately process image and boundary data. The extracted features are then fused in the Global Feature Fusion Module (GFFM), utilizing Transformer technology to further integrate global and detailed information. In the decoder, we employ Feature Compensation Recovery (FCR) to restore critical information lost during the encoding process. Additionally, the network is optimized using a boundary-aware weighted loss strategy. DSTBA-Net aims to achieve high precision in agricultural parcel segmentation and accurate boundary extraction. To evaluate the model’s effectiveness, we conducted experiments on agricultural parcel extraction in Denmark (Europe) and Shandong (Asia). Both quantitative and qualitative analyses show that DSTBA-Net outperforms comparative methods, offering significant advantages in agricultural parcel extraction.

19 January 2022 in Remote Sensing
Verified
Journal Article
Open access
PDF file
CWChengjun Wang
Chengjun Wang
MXMiaozhong Xu
Miaozhong Xu
Yonghua JiangYonghua Jiang
Yonghua Jiang
GZGuo Zhang
Guo Zhang
CHCui Hao
Cui Hao
ZLZhongyuan Lu
Zhongyuan Lu
In hyperspectral imaging (HSI), stripe noise is one of the most common noise types that adversely affects its application. Convolutional neural networks (CNNs) have contributed to state-of-the-art performance in HSI destriping given their powerful feature extraction and learning capabilities. However, it is difficult to obtain paired training samples for real data. Most CNN destriping methods construct a paired training dataset with simulated stripe noise for network training. However, when the stripe noise of real data is complex, destriping performance of the model is constrained. To solve this problem, this study proposes a real HSI stripe removal method using a toward real HSI stripe removal via direction constraint hierarchical feature cascade network (TRS-DCHC). TRS-DCHC uses the stripe noise extract subnetwork to extract stripe patterns from real stripe-containing HSI data and incorporates clean images to form paired training samples. The destriping subnetwork advantageously utilizes a wavelet transform to explicitly decompose stripe and stripe-free components. It also adopts multi-scale feature dense connections and feature fusion to enrich feature information and deeply mine the discriminate features of stripe and stripe-free components. Our experiments on both simulated and real data of various loads showed that TRS-DCHC features better performance in both simulated and real data compared with state-of-the-art method.