利用精密星历产品对BDS-2和BDS-3广播星历的精度进行系统评估,进一步比较分析不同BDS-2和BDS-3卫星星座组合对单点定位的影响,提出一种基于SISRE(signal in space range error)的单点定位加权优化模型。实验结果表明,BDS-2星座中MEO、I...利用精密星历产品对BDS-2和BDS-3广播星历的精度进行系统评估,进一步比较分析不同BDS-2和BDS-3卫星星座组合对单点定位的影响,提出一种基于SISRE(signal in space range error)的单点定位加权优化模型。实验结果表明,BDS-2星座中MEO、IGSO和GEO卫星广播星历轨道误差的RMS分别为2.404 m、3.030 m、12.574 m;BDS-3星座中MEO、IGSO卫星广播星历轨道误差的RMS约为0.5 m和0.8 m;对于SISRE,BDS-2平均优于2 m,BDS-3平均优于1 m;BDS-3配备H钟和Rb钟的卫星钟差及稳定性基本相同。同时单点定位结果表明,BDS-2/BDS-3 IGSO/MEO星座组合定位精度最高。利用提出的SISRE加权模型进行单点定位解算,定位精度在N、E、U方向的平均优化率分别为9.61%、18.55%、11.19%,平均总体优化率达到12.26%,证明了模型的有效性。展开更多
This paper is concerned with a vital topic in image processing:color image forgery detection. The development of computing capabilitieshas led to a breakthrough in hacking and forgery attacks on signal, image,and data...This paper is concerned with a vital topic in image processing:color image forgery detection. The development of computing capabilitieshas led to a breakthrough in hacking and forgery attacks on signal, image,and data communicated over networks. Hence, there is an urgent need fordeveloping efficient image forgery detection algorithms. Two main types offorgery are considered in this paper: splicing and copy-move. Splicing isperformed by inserting a part of an image into another image. On the otherhand, copy-move forgery is performed by copying a part of the image intoanother position in the same image. The proposed approach for splicingdetection is based on the assumption that illumination between the originaland tampered images is different. To detect the difference between the originaland tampered images, the homomorphic transform separates the illuminationcomponent from the reflectance component. The illumination histogramderivative is used for detecting the difference in illumination, and henceforgery detection is accomplished. Prior to performing the forgery detectionprocess, some pre-processing techniques, including histogram equalization,histogram matching, high-pass filtering, homomorphic enhancement, andsingle image super-resolution, are introduced to reinforce the details andchanges between the original and embedded sections. The proposed approachfor copy-move forgery detection is performed with the Speeded Up RobustFeatures (SURF) algorithm, which extracts feature points and feature vectors. Searching for the copied partition is accomplished through matchingwith Euclidian distance and hierarchical clustering. In addition, some preprocessing methods are used with the SURF algorithm, such as histogramequalization and single-mage super-resolution. Simulation results proved thefeasibility and the robustness of the pre-processing step in homomorphicdetection and SURF detection algorithms for splicing and copy-move forgerydetection, respectively.展开更多
High-quality medical microscopic images used for diseases detection are expensive and difficult to store.Therefore,low-resolution images are favorable due to their low storage space and ease of sharing,where the image...High-quality medical microscopic images used for diseases detection are expensive and difficult to store.Therefore,low-resolution images are favorable due to their low storage space and ease of sharing,where the images can be enlarged when needed using Super-Resolution(SR)techniques.However,it is important to maintain the shape and size of the medical images while enlarging them.One of the problems facing SR is that the performance of medical image diagnosis is very poor due to the deterioration of the reconstructed image resolution.Consequently,this paper suggests a multi-SR and classification framework based on Generative Adversarial Network(GAN)to generate high-resolution images with higher quality and finer details to reduce blurring.The proposed framework comprises five GAN models:Enhanced SR Generative Adversarial Networks(ESRGAN),Enhanced deep SR GAN(EDSRGAN),Sub-Pixel-GAN,SRGAN,and Efficient Wider Activation-B GAN(WDSR-b-GAN).To train the proposed models,we have employed images from the famous BreakHis dataset and enlarged them by 4×and 16×upscale factors with the ground truth of the size of 256×256×3.Moreover,several evaluation metrics like Peak Signal-to-Noise Ratio(PSNR),Mean Squared Error(MSE),Structural Similarity Index(SSIM),Multiscale Structural Similarity Index(MS-SSIM),and histogram are applied to make comprehensive and objective comparisons to determine the best methods in terms of efficiency,training time,and storage space.The obtained results reveal the superiority of the proposed models over traditional and benchmark models in terms of color and texture restoration and detection by achieving an accuracy of 99.7433%.展开更多
Diabetic retinopathy,aged macular degeneration,glaucoma etc.are widely prevalent ocular pathologies which are irreversible at advanced stages.Machine learning based automated detection of these pathologies facilitate ...Diabetic retinopathy,aged macular degeneration,glaucoma etc.are widely prevalent ocular pathologies which are irreversible at advanced stages.Machine learning based automated detection of these pathologies facilitate timely clinical interventions,preventing adverse outcomes.Ophthalmologists screen these pathologies with fundus Fluorescein Angiography Images(FFA)which capture retinal components featuring diverse morphologies such as retinal vasculature,macula,optical disk etc.However,these images have low resolutions,hindering the accurate detection of ocular disorders.Construction of high resolution images from these images,by super resolution approaches expedites the diagnosis of pathologies with better accuracy.This paper presents a deep learning network for Single Image Super Resolution(SISR)of fundus fluorescein angiography images,modeled on residual learning,gridded interpolation and Swish activation functions.The image prior for this network is constructed by gridded interpolation which provides better image fidelity compared to other priors.Evaluation of the performance of this network and comparative analysis with benchmark architectures,on a standard dataset shows that the proposed network is superior with respect to performance metrics and computational time.展开更多
In developing countries,medical diagnosis is expensive and time consuming.Hence,automatic diagnosis can be a good cheap alternative.This task can be performed with artificial intelligence tools such as deep Convolutio...In developing countries,medical diagnosis is expensive and time consuming.Hence,automatic diagnosis can be a good cheap alternative.This task can be performed with artificial intelligence tools such as deep Convolutional Neural Networks(CNNs).These tools can be used on medical images to speed up the diagnosis process and save the efforts of specialists.The deep CNNs allow direct learning from the medical images.However,the accessibility of classified data is still the largest challenge,particularly in the field of medical imaging.Transfer learning can deliver an effective and promising solution by transferring knowledge from universal object detection CNNs to medical image classification.However,because of the inhomogeneity and enormous overlap in intensity between medical images in terms of features in the diagnosis of Pneumonia and COVID-19,transfer learning is not usually a robust solution.Single-Image Super-Resolution(SISR)can facilitate learning to enhance computer vision functions,apart from enhancing perceptual image consistency.Consequently,it helps in showing the main features of images.Motivated by the challenging dilemma of Pneumonia and COVID-19 diagnosis,this paper introduces a hybrid CNN model,namely SIGTra,to generate super-resolution versions of X-ray and CT images.It depends on aGenerative Adversarial Network(GAN)for the super-resolution reconstruction problem.Besides,Transfer learning with CNN(TCNN)is adopted for the classification of images.Three different categories of chest X-ray and CT images can be classified with the proposed model.A comparison study is presented between the proposed SIGTra model and the other relatedCNNmodels for COVID-19 detection in terms of precision,sensitivity,and accuracy.展开更多
文摘利用精密星历产品对BDS-2和BDS-3广播星历的精度进行系统评估,进一步比较分析不同BDS-2和BDS-3卫星星座组合对单点定位的影响,提出一种基于SISRE(signal in space range error)的单点定位加权优化模型。实验结果表明,BDS-2星座中MEO、IGSO和GEO卫星广播星历轨道误差的RMS分别为2.404 m、3.030 m、12.574 m;BDS-3星座中MEO、IGSO卫星广播星历轨道误差的RMS约为0.5 m和0.8 m;对于SISRE,BDS-2平均优于2 m,BDS-3平均优于1 m;BDS-3配备H钟和Rb钟的卫星钟差及稳定性基本相同。同时单点定位结果表明,BDS-2/BDS-3 IGSO/MEO星座组合定位精度最高。利用提出的SISRE加权模型进行单点定位解算,定位精度在N、E、U方向的平均优化率分别为9.61%、18.55%、11.19%,平均总体优化率达到12.26%,证明了模型的有效性。
文摘This paper is concerned with a vital topic in image processing:color image forgery detection. The development of computing capabilitieshas led to a breakthrough in hacking and forgery attacks on signal, image,and data communicated over networks. Hence, there is an urgent need fordeveloping efficient image forgery detection algorithms. Two main types offorgery are considered in this paper: splicing and copy-move. Splicing isperformed by inserting a part of an image into another image. On the otherhand, copy-move forgery is performed by copying a part of the image intoanother position in the same image. The proposed approach for splicingdetection is based on the assumption that illumination between the originaland tampered images is different. To detect the difference between the originaland tampered images, the homomorphic transform separates the illuminationcomponent from the reflectance component. The illumination histogramderivative is used for detecting the difference in illumination, and henceforgery detection is accomplished. Prior to performing the forgery detectionprocess, some pre-processing techniques, including histogram equalization,histogram matching, high-pass filtering, homomorphic enhancement, andsingle image super-resolution, are introduced to reinforce the details andchanges between the original and embedded sections. The proposed approachfor copy-move forgery detection is performed with the Speeded Up RobustFeatures (SURF) algorithm, which extracts feature points and feature vectors. Searching for the copied partition is accomplished through matchingwith Euclidian distance and hierarchical clustering. In addition, some preprocessing methods are used with the SURF algorithm, such as histogramequalization and single-mage super-resolution. Simulation results proved thefeasibility and the robustness of the pre-processing step in homomorphicdetection and SURF detection algorithms for splicing and copy-move forgerydetection, respectively.
基金The authors extend their appreciation to the Deputyship for Research&Innovation,Ministry of Education in Saudi Arabia for funding this research work through the project number(IF-PSAU-2021/01/18585).
文摘High-quality medical microscopic images used for diseases detection are expensive and difficult to store.Therefore,low-resolution images are favorable due to their low storage space and ease of sharing,where the images can be enlarged when needed using Super-Resolution(SR)techniques.However,it is important to maintain the shape and size of the medical images while enlarging them.One of the problems facing SR is that the performance of medical image diagnosis is very poor due to the deterioration of the reconstructed image resolution.Consequently,this paper suggests a multi-SR and classification framework based on Generative Adversarial Network(GAN)to generate high-resolution images with higher quality and finer details to reduce blurring.The proposed framework comprises five GAN models:Enhanced SR Generative Adversarial Networks(ESRGAN),Enhanced deep SR GAN(EDSRGAN),Sub-Pixel-GAN,SRGAN,and Efficient Wider Activation-B GAN(WDSR-b-GAN).To train the proposed models,we have employed images from the famous BreakHis dataset and enlarged them by 4×and 16×upscale factors with the ground truth of the size of 256×256×3.Moreover,several evaluation metrics like Peak Signal-to-Noise Ratio(PSNR),Mean Squared Error(MSE),Structural Similarity Index(SSIM),Multiscale Structural Similarity Index(MS-SSIM),and histogram are applied to make comprehensive and objective comparisons to determine the best methods in terms of efficiency,training time,and storage space.The obtained results reveal the superiority of the proposed models over traditional and benchmark models in terms of color and texture restoration and detection by achieving an accuracy of 99.7433%.
文摘Diabetic retinopathy,aged macular degeneration,glaucoma etc.are widely prevalent ocular pathologies which are irreversible at advanced stages.Machine learning based automated detection of these pathologies facilitate timely clinical interventions,preventing adverse outcomes.Ophthalmologists screen these pathologies with fundus Fluorescein Angiography Images(FFA)which capture retinal components featuring diverse morphologies such as retinal vasculature,macula,optical disk etc.However,these images have low resolutions,hindering the accurate detection of ocular disorders.Construction of high resolution images from these images,by super resolution approaches expedites the diagnosis of pathologies with better accuracy.This paper presents a deep learning network for Single Image Super Resolution(SISR)of fundus fluorescein angiography images,modeled on residual learning,gridded interpolation and Swish activation functions.The image prior for this network is constructed by gridded interpolation which provides better image fidelity compared to other priors.Evaluation of the performance of this network and comparative analysis with benchmark architectures,on a standard dataset shows that the proposed network is superior with respect to performance metrics and computational time.
基金This research was funded by the Deanship of Scientific Research at Princess Nourah Bint Abdulrahman University through the Fast-track Research Funding Program.
文摘In developing countries,medical diagnosis is expensive and time consuming.Hence,automatic diagnosis can be a good cheap alternative.This task can be performed with artificial intelligence tools such as deep Convolutional Neural Networks(CNNs).These tools can be used on medical images to speed up the diagnosis process and save the efforts of specialists.The deep CNNs allow direct learning from the medical images.However,the accessibility of classified data is still the largest challenge,particularly in the field of medical imaging.Transfer learning can deliver an effective and promising solution by transferring knowledge from universal object detection CNNs to medical image classification.However,because of the inhomogeneity and enormous overlap in intensity between medical images in terms of features in the diagnosis of Pneumonia and COVID-19,transfer learning is not usually a robust solution.Single-Image Super-Resolution(SISR)can facilitate learning to enhance computer vision functions,apart from enhancing perceptual image consistency.Consequently,it helps in showing the main features of images.Motivated by the challenging dilemma of Pneumonia and COVID-19 diagnosis,this paper introduces a hybrid CNN model,namely SIGTra,to generate super-resolution versions of X-ray and CT images.It depends on aGenerative Adversarial Network(GAN)for the super-resolution reconstruction problem.Besides,Transfer learning with CNN(TCNN)is adopted for the classification of images.Three different categories of chest X-ray and CT images can be classified with the proposed model.A comparison study is presented between the proposed SIGTra model and the other relatedCNNmodels for COVID-19 detection in terms of precision,sensitivity,and accuracy.
