Remote sensing images often need to be merged into a larger mosaic image to support analysis on large areas in many applications.However,the performance of the mosaic imagery may be severely restricted if there are ma...Remote sensing images often need to be merged into a larger mosaic image to support analysis on large areas in many applications.However,the performance of the mosaic imagery may be severely restricted if there are many areas with cloud coverage or if these images used for merging have a long-time span.Therefore,this paper proposes a method of image selection for full coverage image(i.e.a mosaic image with no cloud-contaminated pixels)generation.Specifically,a novel High-Frequency-Aware(HFA)-Net based on Swin-Transformer for region quality grading is presented to provide a data basis for image selection.Spatiotemporal constraints are presented to optimize the image selection.In the temporal dimension,the shortest-time-span constraint shortens the time span of the selected images,obviously improving the timeliness of the image selection results(i.e.with a shorter time span).In the spatial dimension,a spatial continuity constraint is proposed to select data with better quality and larger area,thus improving the radiometric continuity of the results.Experiments on the GF-1 images indicate that the proposed method reduces the averages by 76.1%and 38.7%in terms of the shortest time span compared to the Improved Coverage-oriented Retrieval algorithm(MICR)and Retrieval Method based on Grid Compensation(RMGC)methods,respectively.Moreover,the proposed method also reduces the residual cloud amount by an average of 91.2%,89.8%,and 83.4%when compared to the MICR,RMGC,and Pixel-based Time-series Synthesis Method(PTSM)methods,respectively.展开更多
Processing large amounts of image data such as the Sentinel-2 archive is a computationally demanding task.However,for most applications,many of the images in the archive are redundant and do not contribute to the qual...Processing large amounts of image data such as the Sentinel-2 archive is a computationally demanding task.However,for most applications,many of the images in the archive are redundant and do not contribute to the quality of the final result.An optimization scheme is presented here that selects a subset of the Sentinel-2 archive in order to reduce the amount of processing,while retaining the quality of the resulting output.As a case study,we focused on the creation of a cloud-free composite,covering the global land mass and based on all the images acquired from January 2016 until September 2017.The total amount of available images was 2,128,556.The selection of the optimal subset was based on quicklooks,which correspond to a spatial and spectral subset of the original Sentinel-2 products and are lossy compressed.The selected subset contained 94,093 image tiles in total,reducing the amount of images to be processed to 4.42%of the full set.展开更多
Early correction of childhood malocclusion is timely managing morphological,structural,and functional abnormalities at different dentomaxillofacial developmental stages.The selection of appropriate imaging examination...Early correction of childhood malocclusion is timely managing morphological,structural,and functional abnormalities at different dentomaxillofacial developmental stages.The selection of appropriate imaging examination and comprehensive radiological diagnosis and analysis play an important role in early correction of childhood malocclusion.This expert consensus is a collaborative effort by multidisciplinary experts in dentistry across the nation based on the current clinical evidence,aiming to provide general guidance on appropriate imaging examination selection,comprehensive and accurate imaging assessment for early orthodontic treatment patients.展开更多
Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photod...Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photodynamic therapy(a PDT)holds significant potential for selective imaging and photo-inactivation of ICB while minimizing side effects on normal cells.Drawing inspiration from the elevated hypochlorous acid(HClO)levels in ICB infected phagocytes,herein we firstly designed and synthesized a series of HCl Oresponsive dinuclear Ru(Ⅱ)complexes(Ru1-Ru3)to achieve such a goal.Initially,the luminescence,^(1)O_(2)generation and a PDT activity of these Ru(Ⅱ)complexes were suppressed due to the quenching effect of the azo group,but were recovered after reaction with HCl O in solutions or within ICB infected phagocytes.The detailed results revealed that Ru1 and Ru3 could not only selectively visualize ICB,but also demonstrated remarkable a PDT activity against ICB,surpassing vancomycin both in vitro and in vivo.展开更多
Variational models provide reliable formulation for segmentation of features and their boundaries in an image, following the seminal work of Mumford-Shah （1989, Commun. Pure Appl. Math.） on dividing a general surfac...Variational models provide reliable formulation for segmentation of features and their boundaries in an image, following the seminal work of Mumford-Shah （1989, Commun. Pure Appl. Math.） on dividing a general surface into piecewise smooth sub-surfaces. A cen- tral idea of models based on this work is to minimize the length of feature＇s boundaries （i.e., 7-I1 Hausdorff measure）. However there exist problems with irregular and oscillatory object boundaries, where minimizing such a length is not appropriate, as noted by Barchiesi et al. （2010, SIAM J. Multiscale Model. Simu.） who proposed to miminize ~：2 Lebesgue measure of the ~,-neighborhood of the boundaries. This paper presents a dual level set selective segmen- tation model based on Barchiesi et al. （2010） to automatically select a local feature instead of all global features. Our model uses two level set functions： a global level set which segments all boundaries, and the local level set which evolves and finds the boundary of the object closest to the geometric constraints. Using real life images with oscillatory boundaries, we show qualitative results demonstrating the effectiveness of the proposed method.展开更多
The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar （ISAR） in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and opt...The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar （ISAR） in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and optimal imaging duration. A novel method for optimal imaging instants selection based on the estimation of the Doppler centroid frequencies （DCFs） of a series of images obtained over continuous short durations is proposed. Combined with the optimal imaging duration selection scheme using the image contrast maximization criteria, this method can provide the ship images with the highest focus. Simulated and real data pro- cessing results verify the effectiveness of the proposed imaging method.展开更多
Privacy preservation(PP)in Digital forensics(DF)is a conflicted and non-trivial issue.Existing solutions use the searchable encryption concept and,as a result,are not efficient and support only a keyword search.Moreov...Privacy preservation(PP)in Digital forensics(DF)is a conflicted and non-trivial issue.Existing solutions use the searchable encryption concept and,as a result,are not efficient and support only a keyword search.Moreover,the collected forensic data cannot be analyzed using existing well-known digital tools.This research paper first investigates the lawful requirements for PP in DF based on the organization for economic co-operation and development OECB)privacy guidelines.To have an efficient investigation process and meet the increased volume of data,the presented framework is designed based on the selective imaging concept and advanced encryption standard(AES).The proposed framework has two main modules,namely Selective Imaging Module(SIM)and Selective Analysis Module(SAM).The SIM and SAM modules are implemented based on advanced forensic format 4(AFF4)and SleuthKit open source forensics frameworks,respectively,and,accordingly,the proposed framework is evaluated in a forensically sound manner.The evaluation result is compared with other relevant works and,as a result,the proposed solution provides a privacy-preserving,efficient forensic imaging and analysis process while having also sufficient methods.Moreover,the AFF4 forensic image,produced by the SIM module,can be analyzed not only by SAM,but also by other well-known analysis tools available on the market.展开更多
One of the advantages of laser speckle is detecting microvascular through image processing. This paper proposes a new image processing method for laser speckle, adaptive window method that adaptively processes laser s...One of the advantages of laser speckle is detecting microvascular through image processing. This paper proposes a new image processing method for laser speckle, adaptive window method that adaptively processes laser speckle images in the space. Disadvantage of conventional fixed window method is that it uses the same window size regardless of target areas. Inherently laser speckle contains undesired noise. Thus a large window is helpful for removing the noise, but it results in low resolution of image. Otherwise a small window may detect micro vascular but it has limits in noise removal. To overcome this trade-off, the concept of adaptive window method is newly introduced to conventional laser speckle image analysis. In addition, the modified adaptive window method applied to other selection images. We have compared conventional Laser Speckle Contrast Analysis （LASCA） and its variants with the proposed method in terms of image quality and processing complexity, Moreover compared the result of the accompamed changing sdection images have also been compared.展开更多
Temporal lobe resection is an important treatment option for epilepsy that involves removal of potentially essential brain regions. Selective amygdalohippocampectomy is a widely performed temporal lobe surgery. We sug...Temporal lobe resection is an important treatment option for epilepsy that involves removal of potentially essential brain regions. Selective amygdalohippocampectomy is a widely performed temporal lobe surgery. We suggest starting the incision for selective amygdalohippocampectomy at the inferior temporal gyrus based on diffusion magnetic resonance imaging（MRI） tractography. Diffusion MRI data from 20 normal participants were obtained from Parkinson＇s Progression Markers Initiative（PPMI） database（www.ppmi-info.org）. A tractography algorithm was applied to extract neuronal fiber information for the temporal lobe, hippocampus, and amygdala. Fiber information was analyzed in terms of the number of fibers and betweenness centrality. Distances between starting incisions and surgical target regions were also considered to explore the length of the surgical path. Middle temporal and superior temporal gyrus regions have higher connectivity values than the inferior temporal gyrus and thus are not good candidates for starting the incision. The distances between inferior temporal gyrus and surgical target regions were shorter than those between middle temporal gyrus and target regions. Thus, the inferior temporal gyrus is a good candidate for starting the incision. Starting the incision from the inferior temporal gyrus would spare the important（in terms of betweenness centrality values） middle region and shorten the distance to the target regions of the hippocampus and amygdala.展开更多
Securing digital images is becoming an important concern in today's information security due to the extensive use of secure images that are either transmitted over a network or stored on disks. Image encryption is...Securing digital images is becoming an important concern in today's information security due to the extensive use of secure images that are either transmitted over a network or stored on disks. Image encryption is the most effective way to fulfil confidentiality and protect the privacy of images. Nevertheless, owing to the large size and complex structure of digital images, the computational overhead and processing time needed to carry out full image encryption prove to be limiting factors that inhibit it of being used more heavily in real time. To solve this problem, many recent studies use the selective encryption approach to encrypt significant parts of images with a hope to reduce the encryption overhead. However, it is necessary to realistically evaluate its performance compared to full encryption. In this paper, we study the performance and efficiency of image segmentation methods used in the selective encryption approach, such as edges and face detection methods, in determining the most important parts of visual images. Experiments were performed to analyse the computational results obtained by selective image encryption compared to full image encryption using symmetric encryption algorithms. Experiment results have proven that the selective encryption approach based on edge and face detection can significantly reduce the time of encrypting still visual images as compared to full encryption. Thus, this approach can be considered a good alternative in the implementation of real-time applications that require adequate security levels.展开更多
An innovative and uniform framework based on a combination of Gabor wavelets with principal component analysis （PCA） and multiple discriminant analysis （MDA） is presented in this paper. In this framework, features...An innovative and uniform framework based on a combination of Gabor wavelets with principal component analysis （PCA） and multiple discriminant analysis （MDA） is presented in this paper. In this framework, features are extracted from the optimal random image components using greedy approach. These feature vectors are then projected to subspaces for dimensionality reduction which is used for solving linear problems. The design of Gabor filters, PCA and MDA are crucial processes used for facial feature extraction. The FERET, ORL and YALE face databases are used to generate the results. Experiments show that optimal random image component selection （ORICS） plus MDA outperforms ORICS and subspace projection approach such as ORICS plus PCA. Our method achieves 96.25%, 99.44% and 100% recognition accuracy on the FERET, ORL and YALE databases for 30% training respectively. This is a considerably improved performance compared with other standard methodologies described in the literature.展开更多
Remote sensing images are hard to achieve high compression ratio because of their rich texture. By analyzing the influence of wavelet properties on image compression, this paper proposes wavelet construction rules and...Remote sensing images are hard to achieve high compression ratio because of their rich texture. By analyzing the influence of wavelet properties on image compression, this paper proposes wavelet construction rules and builds a new biorthogonal wavelet construction model with parameters. The model parameters are optimized by using genetic algorithm and adopting energy compaction as the optimization object function. In addition, in order to resolve the computation complexity problem of online construction, according to the image classification rule proposed in this paper we construct wavelets for different classes of images and implement the fast adaptive wavelet selection algorithm （FAWS）. Experimental results show wavelet bases of FAWS gain better compression performance than Daubechies9/7.展开更多
We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spec...We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spectrocopy.The first method is employed to derive a metastasis lung tissue imaging at 3.7 THz with clear contrast between cancerous and healthy areas.The second approach is used to study an osseous tissue under several imaging modalities and achieve full THz spectroscopic imaging based on the frequency domain or on a fixed THz propagation time-delay.Sufficient contrast is achieved which facilitated the identification of regions with different cellular types and density compositions.展开更多
Three amphiphilic poly（fluorene-co-phenylene） derivatives with different side chains （PFP-I, PFP-2, PFP- 3） were designed and synthesized for exploring their detection and imaging of pathogens. Upon incuba- tion w...Three amphiphilic poly（fluorene-co-phenylene） derivatives with different side chains （PFP-I, PFP-2, PFP- 3） were designed and synthesized for exploring their detection and imaging of pathogens. Upon incuba- tion with six kinds of different pathogens, it was found the three polymers could selectively interact with Staphylococcus oureus （S. aureus）. Their selective imaging towards S. aureus were thus realized. The selective imaging towards S. aureus was also confirmed even under the blend of microbes. PFP-3 shows stronger fluorescence imaging signal than PFP-1 and PFP-2. Zeta potential and isothermal titration microcalorimetry （ITC） tests demonstrated that both electrostatic interactions and hydrophobic interac- tions played important roles in the binding between PFPs and pathogens. Thus, amphiphilic PFP-3 exhi- bits great potential for specific imaging ors. aureus in a simple and rapid manner.展开更多
In this paper we present a selective segmentation model using a dual level set variational formulation.Our variational model aims to segment all objects with one level set function(global)and the selected object,which...In this paper we present a selective segmentation model using a dual level set variational formulation.Our variational model aims to segment all objects with one level set function(global)and the selected object,which is the closest to the geometric constraints(markers),with another level set(local).It is a combination of edge detection,markers distance function and active contour without edges.Experimental results show that our model is more robust than previous work.展开更多
基金supported by the National Natural Science Foundation of China[grant numbers 41971422 and 42090010]the Fundamental Research Funds for the Central Universities,China[grant number 2042022dx0001].
文摘Remote sensing images often need to be merged into a larger mosaic image to support analysis on large areas in many applications.However,the performance of the mosaic imagery may be severely restricted if there are many areas with cloud coverage or if these images used for merging have a long-time span.Therefore,this paper proposes a method of image selection for full coverage image(i.e.a mosaic image with no cloud-contaminated pixels)generation.Specifically,a novel High-Frequency-Aware(HFA)-Net based on Swin-Transformer for region quality grading is presented to provide a data basis for image selection.Spatiotemporal constraints are presented to optimize the image selection.In the temporal dimension,the shortest-time-span constraint shortens the time span of the selected images,obviously improving the timeliness of the image selection results(i.e.with a shorter time span).In the spatial dimension,a spatial continuity constraint is proposed to select data with better quality and larger area,thus improving the radiometric continuity of the results.Experiments on the GF-1 images indicate that the proposed method reduces the averages by 76.1%and 38.7%in terms of the shortest time span compared to the Improved Coverage-oriented Retrieval algorithm(MICR)and Retrieval Method based on Grid Compensation(RMGC)methods,respectively.Moreover,the proposed method also reduces the residual cloud amount by an average of 91.2%,89.8%,and 83.4%when compared to the MICR,RMGC,and Pixel-based Time-series Synthesis Method(PTSM)methods,respectively.
文摘Processing large amounts of image data such as the Sentinel-2 archive is a computationally demanding task.However,for most applications,many of the images in the archive are redundant and do not contribute to the quality of the final result.An optimization scheme is presented here that selects a subset of the Sentinel-2 archive in order to reduce the amount of processing,while retaining the quality of the resulting output.As a case study,we focused on the creation of a cloud-free composite,covering the global land mass and based on all the images acquired from January 2016 until September 2017.The total amount of available images was 2,128,556.The selection of the optimal subset was based on quicklooks,which correspond to a spatial and spectral subset of the original Sentinel-2 products and are lossy compressed.The selected subset contained 94,093 image tiles in total,reducing the amount of images to be processed to 4.42%of the full set.
基金supports by the National Natural Science Foundation of China(Nos.82201135)"2015"Cultivation Program for Reserve Talents for Academic Leaders of Nanjing Stomatological School,Medical School of Nanjing University(No.0223A204).
文摘Early correction of childhood malocclusion is timely managing morphological,structural,and functional abnormalities at different dentomaxillofacial developmental stages.The selection of appropriate imaging examination and comprehensive radiological diagnosis and analysis play an important role in early correction of childhood malocclusion.This expert consensus is a collaborative effort by multidisciplinary experts in dentistry across the nation based on the current clinical evidence,aiming to provide general guidance on appropriate imaging examination selection,comprehensive and accurate imaging assessment for early orthodontic treatment patients.
基金supported by National Natural Science Foundation of China(No.22371289)。
文摘Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photodynamic therapy(a PDT)holds significant potential for selective imaging and photo-inactivation of ICB while minimizing side effects on normal cells.Drawing inspiration from the elevated hypochlorous acid(HClO)levels in ICB infected phagocytes,herein we firstly designed and synthesized a series of HCl Oresponsive dinuclear Ru(Ⅱ)complexes(Ru1-Ru3)to achieve such a goal.Initially,the luminescence,^(1)O_(2)generation and a PDT activity of these Ru(Ⅱ)complexes were suppressed due to the quenching effect of the azo group,but were recovered after reaction with HCl O in solutions or within ICB infected phagocytes.The detailed results revealed that Ru1 and Ru3 could not only selectively visualize ICB,but also demonstrated remarkable a PDT activity against ICB,surpassing vancomycin both in vitro and in vivo.
文摘Variational models provide reliable formulation for segmentation of features and their boundaries in an image, following the seminal work of Mumford-Shah （1989, Commun. Pure Appl. Math.） on dividing a general surface into piecewise smooth sub-surfaces. A cen- tral idea of models based on this work is to minimize the length of feature＇s boundaries （i.e., 7-I1 Hausdorff measure）. However there exist problems with irregular and oscillatory object boundaries, where minimizing such a length is not appropriate, as noted by Barchiesi et al. （2010, SIAM J. Multiscale Model. Simu.） who proposed to miminize ~：2 Lebesgue measure of the ~,-neighborhood of the boundaries. This paper presents a dual level set selective segmen- tation model based on Barchiesi et al. （2010） to automatically select a local feature instead of all global features. Our model uses two level set functions： a global level set which segments all boundaries, and the local level set which evolves and finds the boundary of the object closest to the geometric constraints. Using real life images with oscillatory boundaries, we show qualitative results demonstrating the effectiveness of the proposed method.
基金supported by the Innovation Foundation for Scientific Research Base(NJ20140008NJ20150018)+1 种基金the Aeronautical Science Foundation of China(20132052035)the National Defense Basic Scientific Research(B2520110008)
文摘The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar （ISAR） in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and optimal imaging duration. A novel method for optimal imaging instants selection based on the estimation of the Doppler centroid frequencies （DCFs） of a series of images obtained over continuous short durations is proposed. Combined with the optimal imaging duration selection scheme using the image contrast maximization criteria, this method can provide the ship images with the highest focus. Simulated and real data pro- cessing results verify the effectiveness of the proposed imaging method.
基金The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding this work through research group no(RG-1441-531).
文摘Privacy preservation(PP)in Digital forensics(DF)is a conflicted and non-trivial issue.Existing solutions use the searchable encryption concept and,as a result,are not efficient and support only a keyword search.Moreover,the collected forensic data cannot be analyzed using existing well-known digital tools.This research paper first investigates the lawful requirements for PP in DF based on the organization for economic co-operation and development OECB)privacy guidelines.To have an efficient investigation process and meet the increased volume of data,the presented framework is designed based on the selective imaging concept and advanced encryption standard(AES).The proposed framework has two main modules,namely Selective Imaging Module(SIM)and Selective Analysis Module(SAM).The SIM and SAM modules are implemented based on advanced forensic format 4(AFF4)and SleuthKit open source forensics frameworks,respectively,and,accordingly,the proposed framework is evaluated in a forensically sound manner.The evaluation result is compared with other relevant works and,as a result,the proposed solution provides a privacy-preserving,efficient forensic imaging and analysis process while having also sufficient methods.Moreover,the AFF4 forensic image,produced by the SIM module,can be analyzed not only by SAM,but also by other well-known analysis tools available on the market.
基金supported by the SEOUL R&BD NT070079,Korea,the ITRC(Information Technology Research Center)support program supervised by the ⅡTA(Institute for Information Technology Advancement)
文摘One of the advantages of laser speckle is detecting microvascular through image processing. This paper proposes a new image processing method for laser speckle, adaptive window method that adaptively processes laser speckle images in the space. Disadvantage of conventional fixed window method is that it uses the same window size regardless of target areas. Inherently laser speckle contains undesired noise. Thus a large window is helpful for removing the noise, but it results in low resolution of image. Otherwise a small window may detect micro vascular but it has limits in noise removal. To overcome this trade-off, the concept of adaptive window method is newly introduced to conventional laser speckle image analysis. In addition, the modified adaptive window method applied to other selection images. We have compared conventional Laser Speckle Contrast Analysis （LASCA） and its variants with the proposed method in terms of image quality and processing complexity, Moreover compared the result of the accompamed changing sdection images have also been compared.
基金supported by the National Research Foundation of Korea,No.20100023233
文摘Temporal lobe resection is an important treatment option for epilepsy that involves removal of potentially essential brain regions. Selective amygdalohippocampectomy is a widely performed temporal lobe surgery. We suggest starting the incision for selective amygdalohippocampectomy at the inferior temporal gyrus based on diffusion magnetic resonance imaging（MRI） tractography. Diffusion MRI data from 20 normal participants were obtained from Parkinson＇s Progression Markers Initiative（PPMI） database（www.ppmi-info.org）. A tractography algorithm was applied to extract neuronal fiber information for the temporal lobe, hippocampus, and amygdala. Fiber information was analyzed in terms of the number of fibers and betweenness centrality. Distances between starting incisions and surgical target regions were also considered to explore the length of the surgical path. Middle temporal and superior temporal gyrus regions have higher connectivity values than the inferior temporal gyrus and thus are not good candidates for starting the incision. The distances between inferior temporal gyrus and surgical target regions were shorter than those between middle temporal gyrus and target regions. Thus, the inferior temporal gyrus is a good candidate for starting the incision. Starting the incision from the inferior temporal gyrus would spare the important（in terms of betweenness centrality values） middle region and shorten the distance to the target regions of the hippocampus and amygdala.
文摘Securing digital images is becoming an important concern in today's information security due to the extensive use of secure images that are either transmitted over a network or stored on disks. Image encryption is the most effective way to fulfil confidentiality and protect the privacy of images. Nevertheless, owing to the large size and complex structure of digital images, the computational overhead and processing time needed to carry out full image encryption prove to be limiting factors that inhibit it of being used more heavily in real time. To solve this problem, many recent studies use the selective encryption approach to encrypt significant parts of images with a hope to reduce the encryption overhead. However, it is necessary to realistically evaluate its performance compared to full encryption. In this paper, we study the performance and efficiency of image segmentation methods used in the selective encryption approach, such as edges and face detection methods, in determining the most important parts of visual images. Experiments were performed to analyse the computational results obtained by selective image encryption compared to full image encryption using symmetric encryption algorithms. Experiment results have proven that the selective encryption approach based on edge and face detection can significantly reduce the time of encrypting still visual images as compared to full encryption. Thus, this approach can be considered a good alternative in the implementation of real-time applications that require adequate security levels.
文摘An innovative and uniform framework based on a combination of Gabor wavelets with principal component analysis （PCA） and multiple discriminant analysis （MDA） is presented in this paper. In this framework, features are extracted from the optimal random image components using greedy approach. These feature vectors are then projected to subspaces for dimensionality reduction which is used for solving linear problems. The design of Gabor filters, PCA and MDA are crucial processes used for facial feature extraction. The FERET, ORL and YALE face databases are used to generate the results. Experiments show that optimal random image component selection （ORICS） plus MDA outperforms ORICS and subspace projection approach such as ORICS plus PCA. Our method achieves 96.25%, 99.44% and 100% recognition accuracy on the FERET, ORL and YALE databases for 30% training respectively. This is a considerably improved performance compared with other standard methodologies described in the literature.
基金Supported bY the National Natural Science Foundation of China under Grant No.60573150National Defense Basic Research Foundation,the Program for New Century Excellent Talents in Universities and ERIPKU.
文摘Remote sensing images are hard to achieve high compression ratio because of their rich texture. By analyzing the influence of wavelet properties on image compression, this paper proposes wavelet construction rules and builds a new biorthogonal wavelet construction model with parameters. The model parameters are optimized by using genetic algorithm and adopting energy compaction as the optimization object function. In addition, in order to resolve the computation complexity problem of online construction, according to the image classification rule proposed in this paper we construct wavelets for different classes of images and implement the fast adaptive wavelet selection algorithm （FAWS）. Experimental results show wavelet bases of FAWS gain better compression performance than Daubechies9/7.
基金supported by the National Science Foundation,USA
文摘We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spectrocopy.The first method is employed to derive a metastasis lung tissue imaging at 3.7 THz with clear contrast between cancerous and healthy areas.The second approach is used to study an osseous tissue under several imaging modalities and achieve full THz spectroscopic imaging based on the frequency domain or on a fixed THz propagation time-delay.Sufficient contrast is achieved which facilitated the identification of regions with different cellular types and density compositions.
基金supported by the National Natural Science Foundation of China(21773268,21473220)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16020804)
文摘Three amphiphilic poly（fluorene-co-phenylene） derivatives with different side chains （PFP-I, PFP-2, PFP- 3） were designed and synthesized for exploring their detection and imaging of pathogens. Upon incuba- tion with six kinds of different pathogens, it was found the three polymers could selectively interact with Staphylococcus oureus （S. aureus）. Their selective imaging towards S. aureus were thus realized. The selective imaging towards S. aureus was also confirmed even under the blend of microbes. PFP-3 shows stronger fluorescence imaging signal than PFP-1 and PFP-2. Zeta potential and isothermal titration microcalorimetry （ITC） tests demonstrated that both electrostatic interactions and hydrophobic interac- tions played important roles in the binding between PFPs and pathogens. Thus, amphiphilic PFP-3 exhi- bits great potential for specific imaging ors. aureus in a simple and rapid manner.
文摘In this paper we present a selective segmentation model using a dual level set variational formulation.Our variational model aims to segment all objects with one level set function(global)and the selected object,which is the closest to the geometric constraints(markers),with another level set(local).It is a combination of edge detection,markers distance function and active contour without edges.Experimental results show that our model is more robust than previous work.
