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A Moving IR Point Target Detection Algorithm Based on Reverse Phase Feature of Neighborhood in Difference Between Neighbor Frame Images 被引量:3
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作者 朱风云 秦世引 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2006年第3期225-232,共8页
An algorithm for detecting moving IR point target in complex background is proposed, which is based on the Reverse Phase Feature of Neighborhood (RPFN) of target in difference between neighbor frame images that two ... An algorithm for detecting moving IR point target in complex background is proposed, which is based on the Reverse Phase Feature of Neighborhood (RPFN) of target in difference between neighbor frame images that two positions of the target in the difference image are near and the gray values of them are close to in absolute value but with inverse sign. Firstly, pairs of points with RPFN are detected in the difference image between neighbor frame images, with which a virtual vector graph is made, and then the moving point target can be detected by the vectors' sequence cumulated in vector graphs. In addition, a theorem for the convergence of detection of target contrail by this algorithm is given and proved so as to afford a solid guarantee for practical applications of the algorithm proposed in this paper. Finally, some simulation results with 1000 frames from 10 typical images in complex background show that moving point targets with SNR not lower than 1.5 can be detected effectively. 展开更多
关键词 pattern recognition target detection point target difference image RPFN
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Real-time digital image stabilization based on regional field image gray projection 被引量:4
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作者 Weiping Yang Zhilong Zhang +3 位作者 Yan Zhang Xinping Lu Jicheng Li Zhiguang Shi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第1期224-231,共8页
Digital image stabilization technique plays important roles in video surveillance and object acquisition.Many useful electronic image stabilization algorithms have been studied.A real-time algorithm is proposed based ... Digital image stabilization technique plays important roles in video surveillance and object acquisition.Many useful electronic image stabilization algorithms have been studied.A real-time algorithm is proposed based on field image gray projection which enables the regional odd and even field image to be projected into x and y directions and thus to get the regional gray projection curves in x and y directions,respectively.For the odd field image channel,motion parameters can be estimated via iterative minimum absolute difference based on two successive field image regional gray projection curves.Then motion compensations can be obtained after using the Kalman filter method.Finally,the odd field image is adjusted according to the compensations.In the mean time,motion compensation is applied to the even field image channel with the odd field image gray projection curves of the current frame.By minimizing absolute difference between odd and even field image gray projection curves of the current frame,the inter-field motion parameters can be estimated.Therefore,the even field image can be adjusted by combining the inter-field motion parameters and the odd field compensations.Finally,the stabilized image sequence can be obtained by synthesizing the adjusted odd and even field images.Experimental results show that the proposed algorithm can run in real-time and have a good stabilization performance.In addition,image blurring can be improved. 展开更多
关键词 image dithering field based processing electronic image stabilization regional gray projection minimum absolute difference.
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Connectivity differences between adult male and female patients with attention deficit hyperactivity disorder according to resting-state functional MRI 被引量:6
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作者 Bo-yong Park Hyunjin Park 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第1期119-125,共7页
Attention deficit hyperactivity disorder(ADHD) is a pervasive psychiatric disorder that affects both children and adults. Adult male and female patients with ADHD are differentially affected, but few studies have ex... Attention deficit hyperactivity disorder(ADHD) is a pervasive psychiatric disorder that affects both children and adults. Adult male and female patients with ADHD are differentially affected, but few studies have explored the differences. The purpose of this study was to quantify differences between adult male and female patients with ADHD based on neuroimaging and connectivity analysis. Resting-state functional magnetic resonance imaging scans were obtained and preprocessed in 82 patients. Group-wise differences between male and female patients were quantified using degree centrality for different brain regions. The medial-, middle-, and inferior-frontal gyrus, superior parietal lobule, precuneus, supramarginal gyrus, superior- and middle-temporal gyrus, middle occipital gyrus, and cuneus were identified as regions with significant group-wise differences. The identified regions were correlated with clinical scores reflecting depression and anxiety and significant correlations were found. Adult ADHD patients exhibit different levels of depression and anxiety depending on sex, and our study provides insight into how changes in brain circuitry might differentially impact male and female ADHD patients. 展开更多
关键词 neural regeneration connectivity attention deficit hyperactivity disorder sex difference functional magnetic resonance imaging depression anxiety network analysis degree centrality diagnostic and statistical manual score
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Motion connectivity-based initial video object extraction
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作者 王煜坚 吴镇扬 《Journal of Southeast University(English Edition)》 EI CAS 2007年第4期500-506,共7页
In order to obtain the initial video objects from the video sequences, an improved initial video object extraction algorithm based on motion connectivity is proposed. Moving objects in video sequences are highly conne... In order to obtain the initial video objects from the video sequences, an improved initial video object extraction algorithm based on motion connectivity is proposed. Moving objects in video sequences are highly connected and structured, which makes motion connectivity an advanced feature for segmentation. Accordingly, after sharp noise elimination, the cumulated difference image, which exhibits the coherent motion of the moving object, is adaptively thresholded. Then the maximal connected region is labeled, post-processed and output as the final segmenting mask. Hence the initial video object is effectively extracted. Comparative experimental results show that the proposed algorithm extracts the initial video object automatically, promptly and properly, thereby achieving satisfactory subjective and objective performance. 展开更多
关键词 video object extraction motion connectivity adaptive threshold cumulated difference image
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Susceptibility-weighted imaging is suitable for evaluating signal strength in different brain regions of a rabbit model of acute hemorrhagic anemia 被引量:2
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作者 Jun Xia Ni Xie +3 位作者 Anyu Yin Guozhao Teng Fan Lin Yi Lei 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第9期990-992,共3页
Acute hemorrhagic anemia can decrease blood flow and oxygen supply to brain, and affect its physiological function. While detecting changes in brain function in patients with acute hemorrhagic anemia is helpful for pr... Acute hemorrhagic anemia can decrease blood flow and oxygen supply to brain, and affect its physiological function. While detecting changes in brain function in patients with acute hemorrhagic anemia is helpful for preventing neurological complications and evaluating therapeutic effects, clinical changes in the nervous systems of these patients have not received much attention. In part, this is because current techniques can only indirectly detect changes in brain function following onset of anemia, which leads to lags between real changes in brain function and their detection. 展开更多
关键词 Susceptibility-weighted imaging is suitable for evaluating signal strength in different brain regions of a rabbit model of acute hemorrhagic anemia Figure
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A FRAMEWORK FOR AUTOMATED CHANGE DETECTION SYSTEM
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作者 SUI Haigang LI Deren 《Geo-Spatial Information Science》 2001年第3期29-34,共6页
To enhance the ability of remote sensing system to provide accurate,timely,and complete geo_spatial information at regional or global scale,an automated change detection system has been and will continue to be one of ... To enhance the ability of remote sensing system to provide accurate,timely,and complete geo_spatial information at regional or global scale,an automated change detection system has been and will continue to be one of the important and challenging problems in remote sensing.In this paper,the authors propose a framework for automated change detection system at landscape level using various geo_spatial data sources including multi_sensor remotely sensed imagery and ancillary data layers.In this framework,database is the central part and some associated techniques are discussed.These techniques includes five subsystems:automated feature_based image registration,automated change finding,automated change feature extraction and identification,intelligent change recognition,change accuracy assessment and database updating and visualization. 展开更多
关键词 change detection difference image change vector
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Images Difference of ASAR Data for Rice Crop Mapping in Fuzhou, China
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作者 WANG Xiaoqin SHI Xiaoming LING Feilong 《Geo-Spatial Information Science》 2010年第2期123-129,共7页
This paper introduces ENVISAT ASAR data application on rice field mapping in the Fuzhou area, using multi-temporal ASAR dual polarization data acquired in 2005. The procedure for ASAR data processing here includes dat... This paper introduces ENVISAT ASAR data application on rice field mapping in the Fuzhou area, using multi-temporal ASAR dual polarization data acquired in 2005. The procedure for ASAR data processing here includes data calibration, image registration, speckle reduction and conversion of data format from amplitude to dB for backscatter. The backscatter of rice increases with the rice growing stages, which was much different from other land covers. Based on image difference techniques, 6 schemes were designed with ASAR different temporal and polarization data for rice field mapping. Difference images between images in the early period of rice crop and growing or ripening period, are more suitable for rice extraction than those difference images between different polarizations in the same date. The most accurate result of late rice extraction was achieved based on the difference of HH polarization data acquired in October and August. Therefore, for rice field mapping, the temporal information is more important than polarization information. The data during the early growing season of rice is very important for high accuracy rice mapping. 展开更多
关键词 ENVISAT ASAR rice crop mapping images difference Fuzhou
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Interchannel phase difference and stereo sound image localization
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作者 XIE Bosun(Applied Physics Dept., South China University of Technology Guangzhou .510641) 《Chinese Journal of Acoustics》 1998年第1期85-93,共9页
By considering higher order approximation to the interaural phase difference, a more general localization equation for stereo sound image with interchannel phase difference is derived. At very low frequency or low int... By considering higher order approximation to the interaural phase difference, a more general localization equation for stereo sound image with interchannel phase difference is derived. At very low frequency or low interchannel phase difference, the equation can be simplified to Makita theory. In general, image position is obviously affected by frequency.It is shown that image position varying with freqllency is the main reason for image width broadening in stereo reproduction with interchannel phase difference. And an extra interaural sound level difference caused by interchannel phase difference is the main reason for image naturalness degrading. In practice, it is necessary to reduce the interchannel phase difference,at least, to less than 60°. 展开更多
关键词 KHZ Interchannel phase difference and stereo sound image localization
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Experimental investigation of ghost imaging of reflective objects with different surface roughness 被引量:5
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作者 SUQIN NAN YANFENG BAI +4 位作者 XIAOHUI SHI QIAN SHEN LIJIE QU HENGXING LI XIQUAN FU 《Photonics Research》 SCIE EI 2017年第4期372-376,共5页
We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness.The influence of the surface roughness, the transverse size of the test detector, and the reflective ang... We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness.The influence of the surface roughness, the transverse size of the test detector, and the reflective angle on the signal-to-noise ratio(SNR) is analyzed by measuring the second-order correlation of the light field based on classical statistical optics. It is shown that the SNR decreases with an increment of the surface roughness and the detector's transverse size or a decrease of the reflective angle. Additionally, the comparative studies between the rough object and the smooth one under the same conditions are also discussed. 展开更多
关键词 exp Experimental investigation of ghost imaging of reflective objects with different surface roughness SNR test
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Monitoring and analysing the Emirate of Dubai’s land use/land cover changes:an integrated,low-cost remote sensing approach 被引量:1
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作者 Samy Ismail Elmahdy Mohamed Mostafa Mohameda 《International Journal of Digital Earth》 SCIE EI 2018年第11期1132-1150,共19页
This study presents a modified low-cost approach,which integrates the spectral angle mapper and image difference algorithms in order to enhance classification maps for the purpose of monitoring and analysing land use/... This study presents a modified low-cost approach,which integrates the spectral angle mapper and image difference algorithms in order to enhance classification maps for the purpose of monitoring and analysing land use/land cover change between 2000 and 2015 for the Emirate of Dubai.The approach was modified by collecting 320 training samples from QuickBird images with a spatial resolution of 0.6 m,as well as carrying out field observations,followed by the application of a 3×3 Soble filter,sieving classes,majority/minority analysis,and clump classes of the obtained classification maps.The accuracy assessment showed that the targeted 2000,2005,2010 and 2015 classification maps have 88.1252%,89.0699%,90.1225%and 96.0965%accuracy,respectively.The results showed that the built-up area increased by 233.721 km^(2)(5.81%)between 2000 and 2005 and continues to increase even up and till the present time.The assessment of changes in the periods 2000–2005 and 2010–2015 confirmed that net vegetation area losses were more pronounced from 2000 to 2005 than from 2010 to 2015,dropping from 47,618 to 40,820 km^(2),respectively.This study is aimed to assist urban planners and decision-makers,as well as research institutes. 展开更多
关键词 DUBAI change detection image difference SAM algorithm
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