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Image Hiding with High Robustness Based on Dynamic Region Attention in the Wavelet Domain
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作者 Zengxiang Li Yongchong Wu +3 位作者 Alanoud Al Mazroa Donghua Jiang Jianhua Wu Xishun Zhu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期847-869,共23页
Hidden capacity,concealment,security,and robustness are essential indicators of hiding algorithms.Currently,hiding algorithms tend to focus on algorithmic capacity,concealment,and security but often overlook the robus... Hidden capacity,concealment,security,and robustness are essential indicators of hiding algorithms.Currently,hiding algorithms tend to focus on algorithmic capacity,concealment,and security but often overlook the robustness of the algorithms.In practical applications,the container can suffer from damage caused by noise,cropping,and other attacks during transmission,resulting in challenging or even impossible complete recovery of the secret image.An image hiding algorithm based on dynamic region attention in the multi-scale wavelet domain is proposed to address this issue and enhance the robustness of hiding algorithms.In this proposed algorithm,a secret image of size 256×256 is first decomposed using an eight-level Haar wavelet transform.The wavelet transform generates one coefficient in the approximation component and twenty-four detail bands,which are then embedded into the carrier image via a hiding network.During the recovery process,the container image is divided into four non-overlapping parts,each employed to reconstruct a low-resolution secret image.These lowresolution secret images are combined using densemodules to obtain a high-quality secret image.The experimental results showed that even under destructive attacks on the container image,the proposed algorithm is successful in recovering a high-quality secret image,indicating that the algorithm exhibits a high degree of robustness against various attacks.The proposed algorithm effectively addresses the robustness issue by incorporating both spatial and channel attention mechanisms in the multi-scale wavelet domain,making it suitable for practical applications.In conclusion,the image hiding algorithm introduced in this study offers significant improvements in robustness compared to existing algorithms.Its ability to recover high-quality secret images even in the presence of destructive attacksmakes it an attractive option for various applications.Further research and experimentation can explore the algorithm’s performance under different scenarios and expand its potential applications. 展开更多
关键词 image hiding ROBUSTNESS wavelet transform dynamic region attention
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Evaluation of Medical Prescribers’ Theoretical Knowledge on Medical Imaging in the Northern Region of Burkina Faso
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作者 Some Milckisédek Judicaël Marouruana Ouedraogo Pakisba Ali +5 位作者 Tankoano Aïda Ida Savadogo Habibou Kindo Bassirou Ouedraogo Nina-Astrid Bamouni Yomboé Abel Diallo Ousseini 《Open Journal of Radiology》 2024年第2期33-41,共9页
Introduction: Medical imaging is a medical specialty that involves producing images of the human body and interpreting them for diagnostic, therapeutic purposes, and for monitoring the progress of pathologies. We aime... Introduction: Medical imaging is a medical specialty that involves producing images of the human body and interpreting them for diagnostic, therapeutic purposes, and for monitoring the progress of pathologies. We aimed to assess the theoretical knowledge of doctors and interns in medical imaging in the northern region of Burkina Faso. Methodology: This was a descriptive cross-sectional survey based on a self-administered questionnaire. Prescribers knowledge was estimated based on scores derived from questionnaire responses. Results: We collected 106 questionnaires out of 163, i.e. a participation rate of 65.03%. The average knowledge score was 81.71% for the contribution of medical imaging to patient management. It was 60.02% for the indications/counter-indications of radiological examinations and 72.56% for the risks associated with exposure to radiation during these examinations. The score was 59.83% for the methods used to select the appropriate radiological examination. As regards the completeness of the clinical and biological information on the forms requesting imaging examinations, the score was 96.65%. Specialist doctors had the highest overall level of knowledge (74.68%). Conclusion: Improved technical facilities, good initial and in-service training, and interdisciplinary collaboration will help to ensure that imaging tests are properly prescribed, leading to better patient care. 展开更多
关键词 theoretical Knowledge Medical Imaging Northern region Burkina Faso
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Identification of thermal front dynamics in the northern Malacca Strait using ROMS 3D-model
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作者 Ku Nor Afiza Asnida Ku MANSOR Nur Hidayah ROSELI +2 位作者 Poh Heng KOK Fariz Syafiq Mohamad ALI Mohd Fadzil Mohd AKHIR 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期41-57,共17页
The thermal front in the oceanic system is believed to have a significant effect on biological activity.During an era of climate change,changes in heat regulation between the atmosphere and oceanic interior can alter ... The thermal front in the oceanic system is believed to have a significant effect on biological activity.During an era of climate change,changes in heat regulation between the atmosphere and oceanic interior can alter the characteristics of this important feature.Using the simulation results of the 3D Regional Ocean Modelling System(ROMS),we identified the location of thermal fronts and determined their dynamic variability in the area between the southern Andaman Sea and northern Malacca Strait.The Single Image Edge Detection(SIED)algorithm was used to detect the thermal front from model-derived temperature.Results show that a thermal front occurred every year from 2002 to 2012 with the temperature gradient at the location of the front was 0.3°C/km.Compared to the years affected by El Ni?o and negative Indian Ocean Dipole(IOD),the normal years(e.g.,May 2003)show the presence of the thermal front at every selected depth(10,25,50,and 75 m),whereas El Ni?o and negative IOD during 2010 show the presence of the thermal front only at depth of 75 m due to greater warming,leading to the thermocline deepening and enhanced stratification.During May 2003,the thermal front was separated by cooler SST in the southern Andaman Sea and warmer SST in the northern Malacca Strait.The higher SST in the northern Malacca Strait was believed due to the besieged Malacca Strait,which trapped the heat and make it difficult to release while higher chlorophyll a in Malacca Strait is due to the freshwater conduit from nearby rivers(Klang,Langat,Perak,and Selangor).Furthermore,compared to the southern Andaman Sea,the chlorophyll a in the northern Malacca Strait is easier to reach the surface area due to the shallower thermocline,which allows nutrients in the area to reach the surface faster. 展开更多
关键词 regional ocean modelling system thermal front Andaman Sea Malacca Strait single image edge detection algorithm
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A New Region-of-interest Coding Method to Control the Relative Quality of Progressive Decoded Images 被引量:2
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作者 李继良 方向忠 张冬冬 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第4期477-480,共4页
Based on the ideas of controlling relative quality and rearranging bitplanes, a new ROI coding method for JPEG2000 was proposed, which shifts and rearranges bitplanes in units of bitplane groups. It can code arbitrary... Based on the ideas of controlling relative quality and rearranging bitplanes, a new ROI coding method for JPEG2000 was proposed, which shifts and rearranges bitplanes in units of bitplane groups. It can code arbitrary shaped ROI without shape coding, and reserve almost arbitrary percent of background information. It also can control the relative quality of progressive decoded images. In addition, it is easy to be implemented and has low computational cost. 展开更多
关键词 region of interest (ROI) image coding JPEG2000 transform domain
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A mathematical morphological approach for region of interest coding of microscopy image compression
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作者 夏伟强 樊尚春 +3 位作者 邢维巍 刘长庭 李天志 王俊峰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2012年第3期115-121,共7页
A novel mathematical morphological approach for region of interest(ROI) automatic determination and JPEG2000-based coding of microscopy image compression is presented.The algorithm is very fast and requires lower comp... A novel mathematical morphological approach for region of interest(ROI) automatic determination and JPEG2000-based coding of microscopy image compression is presented.The algorithm is very fast and requires lower computing power,which is particularly suitable for some irregular region-based cell microscopy images with poor qualities.Firstly,an active threshold-based method is discussed to create a rough mask of regions of interest(cells).And then some morphological operations are designed and applied to achieve the segmentation of cells.In addition,an extra morphological operation,dilation,is applied to create the final mask with some redundancies to avoid the"edge effect"after removing false cells.Finally,ROI and region of background(ROB) are obtained and encoded individually in different compression ratio flexibly based on the JPEG2000,which can adjust the quality between ROI and ROB without coding for ROI shape.The experimental results certify the effectiveness of the proposed algorithm,and compared with JPEG2000,the proposed algorithm has better performance in both subjective quality and objective quality at the same compression ratios. 展开更多
关键词 mathematical morphology region of interest(ROI) automatic segmentation microscopy image compression JPEG2000
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Method of moving target detection based on sub-image cancellation for single-antenna airborne synthetic aperture radar 被引量:4
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作者 Liu Shujun Yuan Yunneng Gao Fei Mao Shiyi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第3期448-453,共6页
The method of moving target detection based on subimage cancellation for single-antenna airborne SAR is presented. First the subimage is obtained through frequency processing is pointed out. The imaging difference of ... The method of moving target detection based on subimage cancellation for single-antenna airborne SAR is presented. First the subimage is obtained through frequency processing is pointed out. The imaging difference of a stationary objects and moving object in the subimage based on the frequency division is analyzed from the fundamental principle. Then the developed method combines the shear averaging algorithm to focus on the moving target in the subimage, after the clutter suppression and the focusing position in each subimage is obtained. Next the observation model and the relative movement of the moving targets between the subimages estimate the moving targets. The theoretical analysis and simulation results demonstrate that the method is effective and can not only detect the moving targets, but also estimate their motion parameters precisely. 展开更多
关键词 synthetic aperture radar moving target detection sub-image cancellation parameter estimation.
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Study on Regional Image of Henan Province against the Background of Central Plains Rising
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作者 REN Jun 《Journal of Landscape Research》 2013年第4期47-48,共2页
Relevant theories of regional image were elaborated, and significance of regional image for the development of Henan Province was analyzed. On the basis of characteristic cultural resources in the local area, the ways... Relevant theories of regional image were elaborated, and significance of regional image for the development of Henan Province was analyzed. On the basis of characteristic cultural resources in the local area, the ways of building regional image of Henan were explored from the perspectives of orientation of cultural characteristics, regional image identification system and regional image evaluation. 展开更多
关键词 Central PLAinS Economic Zone image of HENAN regionAL image
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Neural stem cell-derived exosomes promote mitochondrial biogenesis and restore abnormal protein distribution in a mouse model of Alzheimer's disease 被引量:1
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作者 Bo Li Yujie Chen +10 位作者 Yan Zhou Xuanran Feng Guojun Gu Shuang Han Nianhao Cheng Yawen Sun Yiming Zhang Jiahui Cheng Qi Zhang Wei Zhang Jianhui Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1593-1601,共9页
Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheime... Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis. 展开更多
关键词 Alzheimer’s disease mitochondrial biogenesis neural stem cell-derived exosome SIRT1-PGC1α regional brain distribution whole brain clearing and imaging
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The effect of zinc supplementation on diarrheal diseases in children in the Niger Delta Sub-Region of Nigeria
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作者 Eme Asuquo Udeme Georgewill +3 位作者 Idorenyin Nta Nkechinyere Enyidah Essiet Umofia Suanu Deekae 《Open Journal of Preventive Medicine》 2012年第2期137-140,共4页
This study evaluated the trend of diarrheal diseases managed with zinc supplementation by comparing it with diarrheal diseases managed without zinc supplementation at the University of Port Harcourt Teaching hospital ... This study evaluated the trend of diarrheal diseases managed with zinc supplementation by comparing it with diarrheal diseases managed without zinc supplementation at the University of Port Harcourt Teaching hospital (UPTH), Nigeria. The study was a descriptive retrospective study done at the Diarrhea Training Unit (DTU) of UPTH to determine the effect of zinc supplementation in the management of diarrhea in children under 5 years. Out of the 134 case records studied, of children aged 0 to 59 months who presented with diarrhea at the DTU, 57 children did not receive zinc supplementation between October and December, 2007 and 77 children received zinc supplementation between October and December 2009. The results showed that (74) 96.1% of patients who received zinc supplementation, and (48) 84.2% of those who did not, had no repeat diarrheal episodes when seen at the follow up clinic. On the other hand, 1.3% of those who received zinc supplementation and 1.8% of those who did not, had increased episodes of diarrhea when seen at the follow up clinic. Of those who received, and those who did not receive zinc supplementation, 2.6% and 14% respectively, had reduced episodes of diarrhea. These findings clearly demonstrate the effectiveness of zinc supplementation in halting the course of diarrheal diseases in children aged 0 to 59 months. We therefore advocate for the use of zinc supplementation in the management of diarrhea in 展开更多
关键词 Diarrheal DISEASES Zinc Supplementation CHILDREN NIGER DELTA sub-region
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COMPUTATION OF STRESS INTENSITY FACTORS BY THE SUB-REGION MIXED FINITE ELEMENT METHOD OF LINES
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作者 Yuan Si Xu Yongjun WILLIAMS F W 《Acta Mechanica Solida Sinica》 SCIE EI 2007年第2期149-162,共14页
Based on the sub-region generalized variationM principle, a sub-region mixed version of the newly-developed semi-analytical 'finite element method of lines' (FEMOL) is proposed in this paper for accurate and effic... Based on the sub-region generalized variationM principle, a sub-region mixed version of the newly-developed semi-analytical 'finite element method of lines' (FEMOL) is proposed in this paper for accurate and efficient computation of stress intensity factors (SIFs) of two-dimensional notches/cracks. The circular regions surrounding notch/crack tips are taken as the complementary energy region in which a number of leading terms of singular solutions for stresses are used, with the sought SIFs being among the unknown coefficients. The rest of the arbitrary domain is taken as the potential energy region in which FEMOL is applied to obtain approximate displacements. A mixed system of ordinary differential equations (ODEs) and algebraic equations is derived via the sub-region generalized variational principle. A singularity removal technique that eliminates the stress parameters from the mixed equation system eventually yields a standard FEMOL ODE system, the solution of which is no longer singular and is simply and efficiently obtained using a standard general-purpose ODE solver. A number of numerical examples, including bi-material notches/cracks in anti-plane and plane elasticity, are given to show the generally excellent performance of the proposed method. 展开更多
关键词 stress intensity factors finite element method of lines sub-region generalized variational principle ordinary differential equation solver
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Altered spontaneous brain activity patterns in hypertensive retinopathy using fractional amplitude of low-frequency fluctuations:a functional magnetic resonance imaging study
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作者 Xue-Lin Wang Xu-Jun Zheng +8 位作者 Li-Juan Zhang Jin-Yu Hu Hong Wei Qian Ling Liang-Qi He Cheng Chen Yi-Xin Wang Xu Chen Yi Shao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第9期1665-1674,共10页
AIM:To study functional brain abnormalities in patients with hypertensive retinopathy(HR)and to discuss the pathophysiological mechanisms of HR by fractional amplitude of low-frequency fluctuations(fALFFs)method.METHO... AIM:To study functional brain abnormalities in patients with hypertensive retinopathy(HR)and to discuss the pathophysiological mechanisms of HR by fractional amplitude of low-frequency fluctuations(fALFFs)method.METHODS:Twenty HR patients and 20 healthy controls(HCs)were respectively recruited.The age,gender,and educational background characteristics of the two groups were similar.After functional magnetic resonance imaging(fMRI)scanning,the subjects’spontaneous brain activity was evaluated with the fALFF method.Receiver operating characteristic(ROC)curve analysis was used to classify the data.Further,we used Pearson’s correlation analysis to explore the relationship between fALFF values in specific brain regions and clinical behaviors in patients with HR.RESULTS:The brain areas of the HR group with lower fALFF values than HCs were the right orbital part of the middle frontal gyrus(RO-MFG)and right lingual gyrus.In contrast,the values of fALFFs in the left middle temporal gyrus(MTG),left superior temporal pole(STP),left middle frontal gyrus(MFG),left superior marginal gyrus(SMG),left superior parietal lobule(SPL),and right supplementary motor area(SMA)were higher in the HR group.The results of a t-test showed that the average values of fALFFs were statistically significantly different in the HR group and HC group(P<0.001).The fALFF values of the left middle frontal gyrus in HR patients were positively correlated with anxiety scores(r=0.9232;P<0.0001)and depression scores(r=0.9682;P<0.0001).CONCLUSION:fALFF values in multiple brain regions of HR patients are abnormal,suggesting that these brain regions in HR patients may be dysfunctional,which may help to reveal the pathophysiological mechanisms of HR. 展开更多
关键词 hypertensive retinopathy fractional amplitude of low-frequency fluctuation brain region magnetic resonance imaging
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Detection of Copy-Move Forgery in Digital Images Using Singular Value Decomposition 被引量:1
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作者 Zaid Nidhal Khudhair Farhan Mohamed +2 位作者 Amjad Rehman Tanzila Saba Saeed Ali bahaj 《Computers, Materials & Continua》 SCIE EI 2023年第2期4135-4147,共13页
This paper presents an improved approach for detecting copy-move forgery based on singular value decomposition(SVD).It is a block-based method where the image is scanned from left to right and top to down by a sliding... This paper presents an improved approach for detecting copy-move forgery based on singular value decomposition(SVD).It is a block-based method where the image is scanned from left to right and top to down by a sliding window with a determined size.At each step,the SVD is determined.First,the diagonal matrix’s maximum value(norm)is selected(representing the scaling factor for SVD and a fixed value for each set of matrix elements even when rotating thematrix or scaled).Then,the similar norms are grouped,and each leading group is separated into many subgroups(elements of each subgroup are neighbors)according to 8-adjacency(the subgroups for each leading group must be far from others by a specific distance).After that,a weight is assigned for each subgroup to classify the image as forgery or not.Finally,the F1 score of the proposed system is measured,reaching 99.1%.This approach is robust against rotation,scaling,noisy images,and illumination variation.It is compared with other similarmethods and presents very promised results. 展开更多
关键词 Forgery image forensic image processing region duplication SVD transformation technological development
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Investigation on the Regional Branding Mode of Modern Agriculture in Guanzhong-Tianshui Economic Zone——From the Perspective of Country-of-origin Image
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作者 LI An-zhou School of Management,Shaanxi University of Technology,Hanzhong 723000,China 《Asian Agricultural Research》 2011年第4期54-57,62,共5页
The theory of the country-of-origin image is discussed and the natural relations between county-of-origin image and the regional brand are explored.The paper points out that the dispersion of agriculture has intensifi... The theory of the country-of-origin image is discussed and the natural relations between county-of-origin image and the regional brand are explored.The paper points out that the dispersion of agriculture has intensified the natural relations to a large extent.The paper probes into the branding status of agriculture in Guanzhong-Tianshui economic zone and points out the problems of it.In the first place,the agricultural industrial system is complete but there is no unified agricultural regional brand;in the second place,the weak awareness on protecting brand leads to the irrational behaviors on damaging brand.From the perspective of the image of the country of origin,the branding mode of agriculture is established and the countermeasures on improving the competitiveness of agricultural products are put forward.Firstly,the leading role of the government should be fully displayed;secondly,the image protection of original production place and regional brand promotion of the agricultural region should be intensified;thirdly,the functions of local pillar industries in protecting image and regional branding should be fully made use of. 展开更多
关键词 Guanzhong-Tianshui ECONOMIC ZONE image of COUNTRY
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A Novel Fast Algorithm of Mono Transition Region Determination with Gray Image 被引量:1
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作者 ZhangAi-hua 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第3期309-312,共4页
There is a transition region between objects and background in any gray image. Many valuable applications of image segmentation and edge detection based on transition region determination have been developed in recent... There is a transition region between objects and background in any gray image. Many valuable applications of image segmentation and edge detection based on transition region determination have been developed in recent years. But, the complexity of calculation for determining transition region is too high. It results in the very limitation of applications based on transition region. A new novel fast method for transition region determination is presented in this paper, which will reduce the complexity of calculation dramatically. Many experiments have showed that this algorithm is effective and correct and will lay a good foundation for applications based on transition region. Key words image segmentation - transition region - maximum point - efficient average gradient (EAG) CLC number TP 391.4 Biography: Zhang Ai-hua (1965-), male, Ph. D candidate, research direction: image processing. 展开更多
关键词 image segmentation transition region maximum point efficient average gradient (EAG)
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A New Method of Multi-Focus Image Fusion Using Laplacian Operator and Region Optimization 被引量:1
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作者 Chao Wang Rui Yuan +3 位作者 Yuqiu Sun Yuanxiang Jiang Changsheng Chen Xiangliang Lin 《Journal of Computer and Communications》 2018年第5期106-118,共13页
Considering the continuous advancement in the field of imaging sensor, a host of other new issues have emerged. A major problem is how to find focus areas more accurately for multi-focus image fusion. The multi-focus ... Considering the continuous advancement in the field of imaging sensor, a host of other new issues have emerged. A major problem is how to find focus areas more accurately for multi-focus image fusion. The multi-focus image fusion extracts the focused information from the source images to construct a global in-focus image which includes more information than any of the source images. In this paper, a novel multi-focus image fusion based on Laplacian operator and region optimization is proposed. The evaluation of image saliency based on Laplacian operator can easily distinguish the focus region and out of focus region. And the decision map obtained by Laplacian operator processing has less the residual information than other methods. For getting precise decision map, focus area and edge optimization based on regional connectivity and edge detection have been taken. Finally, the original images are fused through the decision map. Experimental results indicate that the proposed algorithm outperforms the other series of algorithms in terms of both subjective and objective evaluations. 展开更多
关键词 image FUSION LAPLACIAN OPERATOR Multi-Focus region OPTIMIZATION
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Efficient Image Stitching in the Presence of Dynamic Objects and Structure Misalignment 被引量:1
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作者 Chao Tao Hanqiu Sun +1 位作者 Changcai Yang Jinwen Tian 《Journal of Signal and Information Processing》 2011年第3期205-210,共6页
This paper presents a new method for simultaneously eliminating visual artifacts caused by moving objects and structure misalignment in image stitching. Given that the input images are roughly aligned, our approach is... This paper presents a new method for simultaneously eliminating visual artifacts caused by moving objects and structure misalignment in image stitching. Given that the input images are roughly aligned, our approach is implemented in two stages. In the first stage, we discover motions between input images, and then extract their corresponding regions through a multi-seed based region growing algorithm. In the second stage, with prior information provided by the extracted regions, we perform a graph cut optimization in gradient-domain to determine which pixels to use from each image to achieve seamless stitching. Our method is simple to implement and effective. The experimental results illustrate that the proposed approach can produce comparable or superior results in comparison with state-of-the-art methods. 展开更多
关键词 image STITCHinG Motion ESTIMATE region GROWinG Graph CUT
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Regional Frequency Analysis of Observed Sub-Daily Rainfall Maxima over Eastern China 被引量:2
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作者 Hemin SUN Guojie WANG +3 位作者 Xiucang LI Jing CHEN Buda SU Tong JIANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第2期209-225,共17页
Based on hourly rainfall observational data from 442 stations during 1960-2014, a regional frequency analysis of the annual maxima (AM) sub-daily rainfall series (1-, 2-, 3-, 6-, 12-, and 24-h rainfall, using a mov... Based on hourly rainfall observational data from 442 stations during 1960-2014, a regional frequency analysis of the annual maxima (AM) sub-daily rainfall series (1-, 2-, 3-, 6-, 12-, and 24-h rainfall, using a moving window approach) for eastern China was conducted. Eastern China was divided into 13 homogeneous regions: Northeast (NE1, NE2), Central (C), Central North (CN1, CN2), Central East (CE1, CE2, CE3), Southeast (SE1, SE2, SE3, SE4), and Southwest (SW). The generalized extreme value performed best for the AM series in regions NE, C, CN2, CE1, CE2, SE2, and SW, and the generalized logistic distribution was appropriate in the other regions. Maximum return levels were in the SE4 region, with value ranges of 80-270 mm (1-h to 24-h rainfall) and 108-390 mm (1-h to 24-h rainfall) for 20- and 100 yr, respectively. Minimum return levels were in the CN1 and NE1 regions, with values of 37-104 mm and 53-140 mm for 20 and 100 yr, respectively. Comparing return levels using the optimal and commonly used Pearson-III distribution, the mean return-level differences in eastern China for 1-24-h rainfall varied from -3-4 mm to -23-11 mm (- 10%-10%) for 20-yr events, reaching -6-26 mm (-10%-30%) and -10-133 mm (-10%-90%) for 100-yr events. In view of the large differences in estimated return levels, more attention should be given to frequency analysis of sub-daily rainfall over China, for improved water management and disaster reduction. 展开更多
关键词 sub-daily rainfall annual maxima regional frequency analysis return level eastern China
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Evaluation of Sub-microstructure in Concrete with Low Water-binder Ratio by SEM-BSE Image Analysis 被引量:1
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作者 钱春香 巴明芳 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第4期682-686,共5页
The coarse pore system, interfacial transition zone (ITZ) between aggregate and paste matrix and volume fraction of unhydrated cement in concrete (w/c=0.3) containing mineral admixtures were quantitatively charact... The coarse pore system, interfacial transition zone (ITZ) between aggregate and paste matrix and volume fraction of unhydrated cement in concrete (w/c=0.3) containing mineral admixtures were quantitatively characterized by the scanning electron microscope-backscattered electron (SEM-BSE) image analysis technique. The experimental results show that compound addition of slag and fly ash decreases the coarse porosity from 10.17% to 3.74% and the threshold diameter of coarse pore size from 345 μm to 105 μm compared with concrete (w/c=0.30) without mineral admixtures; Moreover with compound addition of fly ash and slag, the volume proportion of unhydrated cement in paste matrix is reduced by 30%, the maximum amount of coarse pores in the ITZ between aggregate and paste decreases from 13.11% to 5.57% and the thickness of ITZ is reduced by 37% , compared with concrete without mineral admixtures. 展开更多
关键词 scanning electron microscope-backscattered electron imaging sub-microstructure of concrete mineral admixtures
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A Road Extraction Method Based on Region Growing and Mathematical Morphology from Remote Sensing Images
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作者 Yunhe Liu Chi Ma +4 位作者 Li Li Xiaoyan Xing Yong Zhang Zhigang Wang Jiuwei Xu 《Journal of Computer and Communications》 2018年第11期91-97,共7页
Road traffic is the important driving factor for economic and social development. With the rapid increase of vehicle population, road traffic problems such as traffic jam and traffic accident have become the bottlenec... Road traffic is the important driving factor for economic and social development. With the rapid increase of vehicle population, road traffic problems such as traffic jam and traffic accident have become the bottleneck which restricts economic development. In recent years, natural disasters frequently occur in China. Therefore, it is essential to extract road information to compute the degree of road damage for traffic emergency management. A road extraction method based on region growing and mathematical morphology from remote sensing images is proposed in this paper. According to the road features, the remote sensing image is preprocessed to separate road regions from non-road regions preliminarily. After image thresholding, region growing algorithm is used to extract connected regions. Then we sort connected regions by area to exclude the small regions which are probably non-road objects. Finally, the mathematical morphology algorithm is used to fill the holes inside the road regions. The experimental results show that the method proposed can effectively extract roads from remote sensing images. This research also has broad prospects in dealing with traffic emergency management by the government. 展开更多
关键词 region GROWinG MAtheMATICAL MORPHOLOGY ROAD Extraction REMOTE Sensing images
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The Introduction of Promising Mineral Zones Bidkhan Area Using Satellite Imagery
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作者 Alireza Ashofteh 《Open Journal of Geology》 2017年第9期1404-1424,共21页
On the basis of new findings and some evidences related to porphyry mineralization, the exploration region of Bidkhan is considered as a promising mineral region for discovery of porphyry sort deposits. The findings f... On the basis of new findings and some evidences related to porphyry mineralization, the exploration region of Bidkhan is considered as a promising mineral region for discovery of porphyry sort deposits. The findings from various sections indicate that diverse topological events in a zonal and regional time span have resulted in physiochemical (thermodynamic) systems leading to expansive alterations (metamorphism) and mineralization in the central region of Bidkhan area. Alterations such as Propylitic, Silicating, Argillic, Phyllic and even Potassic concentrates at an area of about 10 km2 together with such structures as fissures have created the required and suitable condition for the formation of thermodynamic systems. Such systems are related to mineralization fluids mineralizer that accompanies the sort of activities that are clearly indicative of the existence of an active igneous source all forming a terrene at Bidkhan region which is very similar to mineralization porphyry systems. 展开更多
关键词 Bidkhan KERMAN GEOCHEMISTRY Satellite images Promising regionS MinERAL POTENTIALS
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