Cancer poses a significant threat due to its aggressive nature,potential for widespread metastasis,and inherent heterogeneity,which often leads to resistance to chemotherapy.Lung cancer ranks among the most prevalent ...Cancer poses a significant threat due to its aggressive nature,potential for widespread metastasis,and inherent heterogeneity,which often leads to resistance to chemotherapy.Lung cancer ranks among the most prevalent forms of cancer worldwide,affecting individuals of all genders.Timely and accurate lung cancer detection is critical for improving cancer patients’treatment outcomes and survival rates.Screening examinations for lung cancer detection,however,frequently fall short of detecting small polyps and cancers.To address these limitations,computer-aided techniques for lung cancer detection prove to be invaluable resources for both healthcare practitioners and patients alike.This research implements an enhanced EfficientNetB1 deep learning model for accurate detection and classification using histopathological images.The proposed technique accurately classifies the histopathological images into three distinct classes:(1)no cancer(benign),(2)adenocarcinomas,and(3)squamous cell carcinomas.We evaluated the performance of the proposed technique using the histopathological(LC25000)lung dataset.The preprocessing steps,such as image resizing and augmentation,are followed by loading a pretrained model and applying transfer learning.The dataset is then split into training and validation sets,with fine-tuning and retraining performed on the training dataset.The model’s performance is evaluated on the validation dataset,and the results of lung cancer detection and classification into three classes are obtained.The study’s findings show that an enhanced model achieves exceptional classification accuracy of 99.8%.展开更多
This paper presents a novelmulticlass systemdesigned to detect pleural effusion and pulmonary edema on chest Xray images,addressing the critical need for early detection in healthcare.A new comprehensive dataset was f...This paper presents a novelmulticlass systemdesigned to detect pleural effusion and pulmonary edema on chest Xray images,addressing the critical need for early detection in healthcare.A new comprehensive dataset was formed by combining 28,309 samples from the ChestX-ray14,PadChest,and CheXpert databases,with 10,287,6022,and 12,000 samples representing Pleural Effusion,Pulmonary Edema,and Normal cases,respectively.Consequently,the preprocessing step involves applying the Contrast Limited Adaptive Histogram Equalization(CLAHE)method to boost the local contrast of the X-ray samples,then resizing the images to 380×380 dimensions,followed by using the data augmentation technique.The classification task employs a deep learning model based on the EfficientNet-V1-B4 architecture and is trained using the AdamW optimizer.The proposed multiclass system achieved an accuracy(ACC)of 98.3%,recall of 98.3%,precision of 98.7%,and F1-score of 98.7%.Moreover,the robustness of the model was revealed by the Receiver Operating Characteristic(ROC)analysis,which demonstrated an Area Under the Curve(AUC)of 1.00 for edema and normal cases and 0.99 for effusion.The experimental results demonstrate the superiority of the proposedmulti-class system,which has the potential to assist clinicians in timely and accurate diagnosis,leading to improved patient outcomes.Notably,ablation-CAM visualization at the last convolutional layer portrayed further enhanced diagnostic capabilities with heat maps on X-ray images,which will aid clinicians in interpreting and localizing abnormalities more effectively.展开更多
In the era of big data,the number of images transmitted over the public channel increases exponentially.As a result,it is crucial to devise the efficient and highly secure encryption method to safeguard the sensitive ...In the era of big data,the number of images transmitted over the public channel increases exponentially.As a result,it is crucial to devise the efficient and highly secure encryption method to safeguard the sensitive image.In this paper,an improved sine map(ISM)possessing a larger chaotic region,more complex chaotic behavior and greater unpredictability is proposed and extensively tested.Drawing upon the strengths of ISM,we introduce a lightweight symmetric image encryption cryptosystem in wavelet domain(WDLIC).The WDLIC employs selective encryption to strike a satisfactory balance between security and speed.Initially,only the low-frequency-low-frequency component is chosen to encrypt utilizing classic permutation and diffusion.Then leveraging the statistical properties in wavelet domain,Gaussianization operation which opens the minds of encrypting image information in wavelet domain is first proposed and employed to all sub-bands.Simulations and theoretical analysis demonstrate the high speed and the remarkable effectiveness of WDLIC.展开更多
With the rapid development of 5G technology,it has become fast and easy for people to transmit information on the Internet.Digital images can express information more intuitively,so transmitting information through im...With the rapid development of 5G technology,it has become fast and easy for people to transmit information on the Internet.Digital images can express information more intuitively,so transmitting information through images has excellent applications.This paper uses a new chaotic system called 1D-Sin-Logistic-Map(1D-SLM).1D-SLM has two control parameters,which can provide larger parameter space,and the parameter space in the chaotic state is continuous.Through Lyapunov exponent analysis(LE),bifurcation diagrams analysis,spectral entropy analysis(SE),and 0-1 test,it is verified that 1D-SLM has complex dynamic behavior and is very suitable for cryptography.Compared with other 1D chaotic systems,the 1D-SLM has a larger Lyapunov exponent(LE)and spectral entropy(SE).For color image encryption algorithms,only relying on chaotic mapping is not enough to ensure security.So combined with 1D-SLM,we design a color image encryption algorithm,which is implemented by plane expansion,which reduces the correlation between the three channels of color images.The experimental results show that the proposed cross-plane color image encryption algorithm is safe and resistant to common attack methods.展开更多
目的探讨T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨损伤中的诊断价值。方法对26例关节软骨损伤患者行T_2 star mapping、T_1 images和3D DESS扫描,并将T_1 images、T_2 star mapping与3D DESS图像融合,评价患者股骨...目的探讨T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨损伤中的诊断价值。方法对26例关节软骨损伤患者行T_2 star mapping、T_1 images和3D DESS扫描,并将T_1 images、T_2 star mapping与3D DESS图像融合,评价患者股骨、胫骨、髌骨关节软骨损伤程度并与关节镜结果对比,计算融合伪彩图诊断软骨损伤的特异性、敏感性及与关节镜诊断结果一致性。结果 T_1 images-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为92.8%、93.0%、0.769,T_2 star mapping-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为91.4%、94.2%、0.787。结论 T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨早期损伤评价上优于关节镜。展开更多
The neuronal differentiation of mesenchymal stem cells offers a new strategy for the treatment of neurological disorders.Thus,there is a need to identify a noninvasive and sensitive in vivo imaging approach for real-t...The neuronal differentiation of mesenchymal stem cells offers a new strategy for the treatment of neurological disorders.Thus,there is a need to identify a noninvasive and sensitive in vivo imaging approach for real-time monitoring of transplanted stem cells.Our previous study confirmed that magnetic resonance imaging,with a focus on the ferritin heavy chain 1 reporter gene,could track the proliferation and differentiation of bone marrow mesenchymal stem cells that had been transduced with lentivirus carrying the ferritin heavy chain 1 reporter gene.However,we could not determine whether or when bone marrow mesenchymal stem cells had undergone neuronal differentiation based on changes in the magnetic resonance imaging signal.To solve this problem,we identified a neuron-specific enolase that can be differentially expressed before and after neuronal differentiation in stem cells.In this study,we successfully constructed a lentivirus carrying the neuron-specific enolase promoter and expressing the ferritin heavy chain 1 reporter gene;we used this lentivirus to transduce bone marrow mesenchymal stem cells.Cellular and animal studies showed that the neuron-specific enolase promoter effectively drove the expression of ferritin heavy chain 1 after neuronal differentiation of bone marrow mesenchymal stem cells;this led to intracellular accumulation of iron and corresponding changes in the magnetic resonance imaging signal.In summary,we established an innovative magnetic resonance imaging approach focused on the induction of reporter gene expression by a neuron-specific promoter.This imaging method can be used to noninvasively and sensitively detect neuronal differentiation in stem cells,which may be useful in stem cell-based therapies.展开更多
Satellite remote sensing of inland water body requires a high spatial resolution and a multiband narrow spectral resolution, which makes the fusion between panchromatic(PAN) and multi-spectral(MS) images particularly ...Satellite remote sensing of inland water body requires a high spatial resolution and a multiband narrow spectral resolution, which makes the fusion between panchromatic(PAN) and multi-spectral(MS) images particularly important. Taking the Daquekou section of the Qiantang River as an observation target, four conventional fusion methods widely accepted in satellite image processing, including pan sharpening(PS), principal component analysis(PCA), Gram-Schmidt(GS), and wavelet fusion(WF), are utilized to fuse MS and PAN images of GF-1.The results of subjective and objective evaluation methods application indicate that GS performs the best,followed by the PCA, the WF and the PS in the order of descending. The existence of a large area of the water body is a dominant factor impacting the fusion performance. Meanwhile, the ability of retaining spatial and spectral informations is an important factor affecting the fusion performance of different fusion methods. The fundamental difference of reflectivity information acquisition between water and land is the reason for the failure of conventional fusion methods for land observation such as the PS to be used in the presence of the large water body. It is suggested that the adoption of the conventional fusion methods in the observing water body as the main target should be taken with caution. The performances of the fusion methods need re-assessment when the large-scale water body is present in the remote sensing image or when the research aims for the water body observation.展开更多
Over the past decade,a growing number of studies have reported transcription factor-based in situ reprogramming that can directly conve rt endogenous glial cells into functional neurons as an alternative approach for ...Over the past decade,a growing number of studies have reported transcription factor-based in situ reprogramming that can directly conve rt endogenous glial cells into functional neurons as an alternative approach for n euro regeneration in the adult mammalian central ne rvous system.Howeve r,many questions remain regarding how a terminally differentiated glial cell can transform into a delicate neuron that forms part of the intricate brain circuitry.In addition,concerns have recently been raised around the absence of astrocyte-to-neuron conversion in astrocytic lineage-tra cing mice.In this study,we employed repetitive two-photon imaging to continuously capture the in situ astrocyte-to-neuron conversion process following ecto pic expression of the neural transcription factor NeuroD1 in both prolife rating reactive astrocytes and lineage-tra ced astrocytes in the mouse cortex.Time-lapse imaging over several wee ks revealed the ste p-by-step transition from a typical astrocyte with numero us short,tapered branches to a typical neuro n with a few long neurites and dynamic growth cones that actively explored the local environment.In addition,these lineage-converting cells were able to migrate ra dially or to ngentially to relocate to suitable positions.Furthermore,two-photon Ca2+imaging and patch-clamp recordings confirmed that the newly generated neuro ns exhibited synchronous calcium signals,repetitive action potentials,and spontaneous synaptic responses,suggesting that they had made functional synaptic connections within local neural circuits.In conclusion,we directly visualized the step-by-step lineage conversion process from astrocytes to functional neurons in vivo and unambiguously demonstrated that adult mammalian brains are highly plastic with respect to their potential for neuro regeneration and neural circuit reconstruction.展开更多
认知功能障碍是1型发作性睡病(narcolepsy type 1,NT1)的常见症状之一,严重影响患者的学习工作。目前研究表明,NT1患者在注意力、记忆、执行功能等认知领域存在显著障碍。NT1认知功能障碍具体机制不明确,动物研究显示脑脊液食欲素分泌...认知功能障碍是1型发作性睡病(narcolepsy type 1,NT1)的常见症状之一,严重影响患者的学习工作。目前研究表明,NT1患者在注意力、记忆、执行功能等认知领域存在显著障碍。NT1认知功能障碍具体机制不明确,动物研究显示脑脊液食欲素分泌缺乏与认知障碍密切相关,同时近些年来神经影像学已结合不同的研究方法应用于NT1认知障碍机制的研究,能反映相关结构和功能异常。1型发作性睡病的认知功能障碍治疗至今仍缺乏有循证依据的治疗手段。本文对1型发作性睡病的认知功能障碍进展做一综述。展开更多
The brightness reversal of submarine sand waves appearing in the small satellite constellation for environ- ment and disaster monitoring and forecasting （＂HJ- 1A/B＂） CCD sun glitter images can affect the observati...The brightness reversal of submarine sand waves appearing in the small satellite constellation for environ- ment and disaster monitoring and forecasting （＂HJ- 1A/B＂） CCD sun glitter images can affect the observation and depth inversion of sand wave topography. The simulations of the normalized sun glitter radiance on the submarine sand waves confirm that the reversal would happen at a specific sensor viewing angle, defined as the critical angle. The difference between the calculated critical angle position and the reversal position in the image is about 1＇, which is excellent in agreement. Both the simulation and actual image show that sand wave crests would be indistinct at the reversal position, which may cause problems when using these sun glitter images to analyze spatial characteristics and migration of sand waves. When using the sun glitter image to obtain the depth inversion, one should take the advantage of image properties of sand waves and choose the location in between the reversal position and the brightest position. It is also necessary to pay attention to the brightness reversal when using ＂HI-1A/B＂ CCD images to analyze other oceanic features, such as internal waves, oil slicks, eddies, and ship wakes.展开更多
文摘Cancer poses a significant threat due to its aggressive nature,potential for widespread metastasis,and inherent heterogeneity,which often leads to resistance to chemotherapy.Lung cancer ranks among the most prevalent forms of cancer worldwide,affecting individuals of all genders.Timely and accurate lung cancer detection is critical for improving cancer patients’treatment outcomes and survival rates.Screening examinations for lung cancer detection,however,frequently fall short of detecting small polyps and cancers.To address these limitations,computer-aided techniques for lung cancer detection prove to be invaluable resources for both healthcare practitioners and patients alike.This research implements an enhanced EfficientNetB1 deep learning model for accurate detection and classification using histopathological images.The proposed technique accurately classifies the histopathological images into three distinct classes:(1)no cancer(benign),(2)adenocarcinomas,and(3)squamous cell carcinomas.We evaluated the performance of the proposed technique using the histopathological(LC25000)lung dataset.The preprocessing steps,such as image resizing and augmentation,are followed by loading a pretrained model and applying transfer learning.The dataset is then split into training and validation sets,with fine-tuning and retraining performed on the training dataset.The model’s performance is evaluated on the validation dataset,and the results of lung cancer detection and classification into three classes are obtained.The study’s findings show that an enhanced model achieves exceptional classification accuracy of 99.8%.
文摘This paper presents a novelmulticlass systemdesigned to detect pleural effusion and pulmonary edema on chest Xray images,addressing the critical need for early detection in healthcare.A new comprehensive dataset was formed by combining 28,309 samples from the ChestX-ray14,PadChest,and CheXpert databases,with 10,287,6022,and 12,000 samples representing Pleural Effusion,Pulmonary Edema,and Normal cases,respectively.Consequently,the preprocessing step involves applying the Contrast Limited Adaptive Histogram Equalization(CLAHE)method to boost the local contrast of the X-ray samples,then resizing the images to 380×380 dimensions,followed by using the data augmentation technique.The classification task employs a deep learning model based on the EfficientNet-V1-B4 architecture and is trained using the AdamW optimizer.The proposed multiclass system achieved an accuracy(ACC)of 98.3%,recall of 98.3%,precision of 98.7%,and F1-score of 98.7%.Moreover,the robustness of the model was revealed by the Receiver Operating Characteristic(ROC)analysis,which demonstrated an Area Under the Curve(AUC)of 1.00 for edema and normal cases and 0.99 for effusion.The experimental results demonstrate the superiority of the proposedmulti-class system,which has the potential to assist clinicians in timely and accurate diagnosis,leading to improved patient outcomes.Notably,ablation-CAM visualization at the last convolutional layer portrayed further enhanced diagnostic capabilities with heat maps on X-ray images,which will aid clinicians in interpreting and localizing abnormalities more effectively.
基金Project supported by the Key Area Research and Development Program of Guangdong Province,China(Grant No.2022B0701180001)the National Natural Science Foundation of China(Grant No.61801127)+1 种基金the Science Technology Planning Project of Guangdong Province,China(Grant Nos.2019B010140002 and 2020B111110002)the Guangdong–Hong Kong–Macao Joint Innovation Field Project(Grant No.2021A0505080006).
文摘In the era of big data,the number of images transmitted over the public channel increases exponentially.As a result,it is crucial to devise the efficient and highly secure encryption method to safeguard the sensitive image.In this paper,an improved sine map(ISM)possessing a larger chaotic region,more complex chaotic behavior and greater unpredictability is proposed and extensively tested.Drawing upon the strengths of ISM,we introduce a lightweight symmetric image encryption cryptosystem in wavelet domain(WDLIC).The WDLIC employs selective encryption to strike a satisfactory balance between security and speed.Initially,only the low-frequency-low-frequency component is chosen to encrypt utilizing classic permutation and diffusion.Then leveraging the statistical properties in wavelet domain,Gaussianization operation which opens the minds of encrypting image information in wavelet domain is first proposed and employed to all sub-bands.Simulations and theoretical analysis demonstrate the high speed and the remarkable effectiveness of WDLIC.
基金This research was supported by the National Natural Science Foundation of China(61802212).
文摘With the rapid development of 5G technology,it has become fast and easy for people to transmit information on the Internet.Digital images can express information more intuitively,so transmitting information through images has excellent applications.This paper uses a new chaotic system called 1D-Sin-Logistic-Map(1D-SLM).1D-SLM has two control parameters,which can provide larger parameter space,and the parameter space in the chaotic state is continuous.Through Lyapunov exponent analysis(LE),bifurcation diagrams analysis,spectral entropy analysis(SE),and 0-1 test,it is verified that 1D-SLM has complex dynamic behavior and is very suitable for cryptography.Compared with other 1D chaotic systems,the 1D-SLM has a larger Lyapunov exponent(LE)and spectral entropy(SE).For color image encryption algorithms,only relying on chaotic mapping is not enough to ensure security.So combined with 1D-SLM,we design a color image encryption algorithm,which is implemented by plane expansion,which reduces the correlation between the three channels of color images.The experimental results show that the proposed cross-plane color image encryption algorithm is safe and resistant to common attack methods.
文摘目的探讨T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨损伤中的诊断价值。方法对26例关节软骨损伤患者行T_2 star mapping、T_1 images和3D DESS扫描,并将T_1 images、T_2 star mapping与3D DESS图像融合,评价患者股骨、胫骨、髌骨关节软骨损伤程度并与关节镜结果对比,计算融合伪彩图诊断软骨损伤的特异性、敏感性及与关节镜诊断结果一致性。结果 T_1 images-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为92.8%、93.0%、0.769,T_2 star mapping-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为91.4%、94.2%、0.787。结论 T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨早期损伤评价上优于关节镜。
基金supported by the National Natural Science Foundation of China,No.81771892(to JHC).
文摘The neuronal differentiation of mesenchymal stem cells offers a new strategy for the treatment of neurological disorders.Thus,there is a need to identify a noninvasive and sensitive in vivo imaging approach for real-time monitoring of transplanted stem cells.Our previous study confirmed that magnetic resonance imaging,with a focus on the ferritin heavy chain 1 reporter gene,could track the proliferation and differentiation of bone marrow mesenchymal stem cells that had been transduced with lentivirus carrying the ferritin heavy chain 1 reporter gene.However,we could not determine whether or when bone marrow mesenchymal stem cells had undergone neuronal differentiation based on changes in the magnetic resonance imaging signal.To solve this problem,we identified a neuron-specific enolase that can be differentially expressed before and after neuronal differentiation in stem cells.In this study,we successfully constructed a lentivirus carrying the neuron-specific enolase promoter and expressing the ferritin heavy chain 1 reporter gene;we used this lentivirus to transduce bone marrow mesenchymal stem cells.Cellular and animal studies showed that the neuron-specific enolase promoter effectively drove the expression of ferritin heavy chain 1 after neuronal differentiation of bone marrow mesenchymal stem cells;this led to intracellular accumulation of iron and corresponding changes in the magnetic resonance imaging signal.In summary,we established an innovative magnetic resonance imaging approach focused on the induction of reporter gene expression by a neuron-specific promoter.This imaging method can be used to noninvasively and sensitively detect neuronal differentiation in stem cells,which may be useful in stem cell-based therapies.
基金The National Key Research and Development Program of China under contract Nos 2016YFC1400901 and 2018YFC1406600the National Natural Science Foundation of China under contract No.40706057+1 种基金the Environmental Protection and Science and Technology Plan Project of Zhejiang Province of China under contract No.2013A021the Research Center for Air Pollution and Health of Zhejiang University
文摘Satellite remote sensing of inland water body requires a high spatial resolution and a multiband narrow spectral resolution, which makes the fusion between panchromatic(PAN) and multi-spectral(MS) images particularly important. Taking the Daquekou section of the Qiantang River as an observation target, four conventional fusion methods widely accepted in satellite image processing, including pan sharpening(PS), principal component analysis(PCA), Gram-Schmidt(GS), and wavelet fusion(WF), are utilized to fuse MS and PAN images of GF-1.The results of subjective and objective evaluation methods application indicate that GS performs the best,followed by the PCA, the WF and the PS in the order of descending. The existence of a large area of the water body is a dominant factor impacting the fusion performance. Meanwhile, the ability of retaining spatial and spectral informations is an important factor affecting the fusion performance of different fusion methods. The fundamental difference of reflectivity information acquisition between water and land is the reason for the failure of conventional fusion methods for land observation such as the PS to be used in the presence of the large water body. It is suggested that the adoption of the conventional fusion methods in the observing water body as the main target should be taken with caution. The performances of the fusion methods need re-assessment when the large-scale water body is present in the remote sensing image or when the research aims for the water body observation.
基金supported by the National Natural Science Foundation of China,No.31970906(to WLei)the Natural Science Foundation of Guangdong Province,No.2020A1515011079(to WLei)+4 种基金Key Technologies R&D Program of Guangdong Province,No.2018B030332001(to GC)Science and Technology Projects of Guangzhou,No.202206060002(to GC)the Youth Science Program of the National Natural Science Foundation of China,No.32100793(to ZX)the Pearl River Innovation and Entrepreneurship Team,No.2021ZT09 Y552Yi-Liang Liu Endowment Fund from Jinan University Education Development Foundation。
文摘Over the past decade,a growing number of studies have reported transcription factor-based in situ reprogramming that can directly conve rt endogenous glial cells into functional neurons as an alternative approach for n euro regeneration in the adult mammalian central ne rvous system.Howeve r,many questions remain regarding how a terminally differentiated glial cell can transform into a delicate neuron that forms part of the intricate brain circuitry.In addition,concerns have recently been raised around the absence of astrocyte-to-neuron conversion in astrocytic lineage-tra cing mice.In this study,we employed repetitive two-photon imaging to continuously capture the in situ astrocyte-to-neuron conversion process following ecto pic expression of the neural transcription factor NeuroD1 in both prolife rating reactive astrocytes and lineage-tra ced astrocytes in the mouse cortex.Time-lapse imaging over several wee ks revealed the ste p-by-step transition from a typical astrocyte with numero us short,tapered branches to a typical neuro n with a few long neurites and dynamic growth cones that actively explored the local environment.In addition,these lineage-converting cells were able to migrate ra dially or to ngentially to relocate to suitable positions.Furthermore,two-photon Ca2+imaging and patch-clamp recordings confirmed that the newly generated neuro ns exhibited synchronous calcium signals,repetitive action potentials,and spontaneous synaptic responses,suggesting that they had made functional synaptic connections within local neural circuits.In conclusion,we directly visualized the step-by-step lineage conversion process from astrocytes to functional neurons in vivo and unambiguously demonstrated that adult mammalian brains are highly plastic with respect to their potential for neuro regeneration and neural circuit reconstruction.
文摘认知功能障碍是1型发作性睡病(narcolepsy type 1,NT1)的常见症状之一,严重影响患者的学习工作。目前研究表明,NT1患者在注意力、记忆、执行功能等认知领域存在显著障碍。NT1认知功能障碍具体机制不明确,动物研究显示脑脊液食欲素分泌缺乏与认知障碍密切相关,同时近些年来神经影像学已结合不同的研究方法应用于NT1认知障碍机制的研究,能反映相关结构和功能异常。1型发作性睡病的认知功能障碍治疗至今仍缺乏有循证依据的治疗手段。本文对1型发作性睡病的认知功能障碍进展做一综述。
基金The Marine Scientific Public Welfare Research Special Foundation under contract No.201105001the Key Laboratory of Ocean Dynamic Processed and Satellite Oceanography under contract No.SOED1006
文摘The brightness reversal of submarine sand waves appearing in the small satellite constellation for environ- ment and disaster monitoring and forecasting （＂HJ- 1A/B＂） CCD sun glitter images can affect the observation and depth inversion of sand wave topography. The simulations of the normalized sun glitter radiance on the submarine sand waves confirm that the reversal would happen at a specific sensor viewing angle, defined as the critical angle. The difference between the calculated critical angle position and the reversal position in the image is about 1＇, which is excellent in agreement. Both the simulation and actual image show that sand wave crests would be indistinct at the reversal position, which may cause problems when using these sun glitter images to analyze spatial characteristics and migration of sand waves. When using the sun glitter image to obtain the depth inversion, one should take the advantage of image properties of sand waves and choose the location in between the reversal position and the brightest position. It is also necessary to pay attention to the brightness reversal when using ＂HI-1A/B＂ CCD images to analyze other oceanic features, such as internal waves, oil slicks, eddies, and ship wakes.
