In many image resolution enhancement applications,the blurring process of the imaging system is unknown.This paper discusses the problem of single image blind resolution enhancement without estimating the point spread...In many image resolution enhancement applications,the blurring process of the imaging system is unknown.This paper discusses the problem of single image blind resolution enhancement without estimating the point spread function(PSF).A regularization model is constructed for image enhancement based on the prior informaton of image error and image gray value,which does not need any prior information of PSF.Moreover,through the solution of Euler equations,an anisotropic nonlinear diffusion equation are obtained,which can avoid the high computational cost of regularization model.Furthermore,in order to get sub-pixel superresolved image,the regularization model for image enhancement is extended to the enlargement of image,which can enlarge and enhance image at the same time.Last,to get clearer edges,a high frequency enhancement filter is used on the superresolved image.Numerical results show that the new model can get much clearer super-resolution images than traditional methods,and the peak signal to noise ratios (PSNRs) are also higher than traditional methods.展开更多
In original Zernike moments subpixel edge operator, ideal step edge model is chosen for calculating four parameters of a pixel point, and therefore principle deviation is caused by edge model. In order to discuss the ...In original Zernike moments subpixel edge operator, ideal step edge model is chosen for calculating four parameters of a pixel point, and therefore principle deviation is caused by edge model. In order to discuss the effect of principle deviation on edge location, sampled edge model is chosen for calculating edge parameters, principle deviation of edge translation l is derived based on Zernike moments edge detection theory, and modified formula of l is given for Zernike moments operator with masks of 5×5 size. Both theory analysis and testing result demonstrate that principle deviation is zero when edge translation l is limited in central pixel of a sampled window. In another case, the modification of l should be considered, which results in edge location accuracy of non-subpixel level for this subpixel edge operator.展开更多
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
It is well-known that classical quality measures,such as Mean Squared Error(MSE),Weighted Mean Squared Error(WMSE)or Peak Signal-to-Noise Ratio(PSNR),are not always corresponding with visual observations.Structural si...It is well-known that classical quality measures,such as Mean Squared Error(MSE),Weighted Mean Squared Error(WMSE)or Peak Signal-to-Noise Ratio(PSNR),are not always corresponding with visual observations.Structural similarity based image quality assessment was proposed under the assumption that the Human Visual System(HVS)is highly adapted for extracting structural information from an image.While the demand on high color quality increases in the media industry,color loss will make the visual quality different.In this paper,we proposed an improved quality assessment(QA)method by adding color comparison into the structural similarity(SSIM)measurement system for evaluating color image quality.Then we divided the task of similarity measurement into four comparisons:luminance,contrast,structure,and color.Experimental results show that the predicted quality scores of the proposed method are more effective and consistent with visual quality than the classical methods using five different distortion types of color image sets.展开更多
For video streaming over lossy channels, intra refresh can mitigate the error-propagation effect caused by packet losses Besides some intra-mode macroblocks （MBs） generated by the ＂Lagrangian rate-distortion＂ or ...For video streaming over lossy channels, intra refresh can mitigate the error-propagation effect caused by packet losses Besides some intra-mode macroblocks （MBs） generated by the ＂Lagrangian rate-distortion＂ or ＂Sum of absolute difference＂ mode decision, the encoder or transcoder possibly needs to increase some ＂forced＂ intra-mode MBs for robust video streaming. Based on the error-propagation analysis in a group of pictures （GOP）, we propose an unequal Forced-Intra-Refresh （FIR） scheme to improve packet loss resilience of video streaming. According to a GOP-level error-propagation model, the proposed unequal FIR scheme can optimally increase the unequal number of forced intra-mode MBs for different frames in a GOP. Simulation results showed that the proposed scheme can effectively enhance the robustness of video streaming under different channel conditions, and achieve about 0. 1-0.9 dB gains over the average FIR scheme in H.264/AVC tools.展开更多
Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular...Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular LDPC codes with Unequal Error Protection (UEP)property is designed in this letter. Simulation results show that the transmission quality of the image may be effectively improved with this class of irregular LDPC code.展开更多
Purpose： This study aimed to investigate the construct of external visual imagery （EVI） vs. internal visual imagery （IV/） by comparing the athletes＇ imagery ability with their levels of skill and types of sports...Purpose： This study aimed to investigate the construct of external visual imagery （EVI） vs. internal visual imagery （IV/） by comparing the athletes＇ imagery ability with their levels of skill and types of sports. Methods： Seventy-two young athletes in open （n = 45） or closed （n = 27） sports and with different skill levels completed 2 custom-designed tasks. The EVI task involved the subject generating and visualizing the rotated images of different body parts, whereas the IVI task involved the subject visualizing himself or herself performing specific movements. Results： The significant Skill-Level x Sport Type interactions for the EVI task revealed that participants who specialized in open sports and had higher skill-levels had a higher accuracy rate as compared to the other subgroups. For the IVI task, the differences between the groups were less clear： those with higher skill-levels or open sports had a higher accuracy rate than those with lower skill-levels or closed sports. Conclusion： EVI involves the visualization of others and the environment, and would be relevant to higher skill-level athletes who engage in open sports. IVI, in contrast, tends to be more self-oriented and would be relevant for utilization by higher skill-level athletes regardless of sport type.展开更多
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
基金Supported by the National Natural Science Foundation of China(No.60272013) and National Excellent Doctoral DissertationFund of China(No.200140)
文摘In many image resolution enhancement applications,the blurring process of the imaging system is unknown.This paper discusses the problem of single image blind resolution enhancement without estimating the point spread function(PSF).A regularization model is constructed for image enhancement based on the prior informaton of image error and image gray value,which does not need any prior information of PSF.Moreover,through the solution of Euler equations,an anisotropic nonlinear diffusion equation are obtained,which can avoid the high computational cost of regularization model.Furthermore,in order to get sub-pixel superresolved image,the regularization model for image enhancement is extended to the enlargement of image,which can enlarge and enhance image at the same time.Last,to get clearer edges,a high frequency enhancement filter is used on the superresolved image.Numerical results show that the new model can get much clearer super-resolution images than traditional methods,and the peak signal to noise ratios (PSNRs) are also higher than traditional methods.
基金Supported by National Natural Science Foundation(No.50605045)Liaoning Province Education Administration Fund (No.05L307)
文摘In original Zernike moments subpixel edge operator, ideal step edge model is chosen for calculating four parameters of a pixel point, and therefore principle deviation is caused by edge model. In order to discuss the effect of principle deviation on edge location, sampled edge model is chosen for calculating edge parameters, principle deviation of edge translation l is derived based on Zernike moments edge detection theory, and modified formula of l is given for Zernike moments operator with masks of 5×5 size. Both theory analysis and testing result demonstrate that principle deviation is zero when edge translation l is limited in central pixel of a sampled window. In another case, the modification of l should be considered, which results in edge location accuracy of non-subpixel level for this subpixel edge operator.
文摘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.
文摘It is well-known that classical quality measures,such as Mean Squared Error(MSE),Weighted Mean Squared Error(WMSE)or Peak Signal-to-Noise Ratio(PSNR),are not always corresponding with visual observations.Structural similarity based image quality assessment was proposed under the assumption that the Human Visual System(HVS)is highly adapted for extracting structural information from an image.While the demand on high color quality increases in the media industry,color loss will make the visual quality different.In this paper,we proposed an improved quality assessment(QA)method by adding color comparison into the structural similarity(SSIM)measurement system for evaluating color image quality.Then we divided the task of similarity measurement into four comparisons:luminance,contrast,structure,and color.Experimental results show that the predicted quality scores of the proposed method are more effective and consistent with visual quality than the classical methods using five different distortion types of color image sets.
基金Project (No. 60332030) supported by the National Natural ScienceFoundation of China
文摘For video streaming over lossy channels, intra refresh can mitigate the error-propagation effect caused by packet losses Besides some intra-mode macroblocks （MBs） generated by the ＂Lagrangian rate-distortion＂ or ＂Sum of absolute difference＂ mode decision, the encoder or transcoder possibly needs to increase some ＂forced＂ intra-mode MBs for robust video streaming. Based on the error-propagation analysis in a group of pictures （GOP）, we propose an unequal Forced-Intra-Refresh （FIR） scheme to improve packet loss resilience of video streaming. According to a GOP-level error-propagation model, the proposed unequal FIR scheme can optimally increase the unequal number of forced intra-mode MBs for different frames in a GOP. Simulation results showed that the proposed scheme can effectively enhance the robustness of video streaming under different channel conditions, and achieve about 0. 1-0.9 dB gains over the average FIR scheme in H.264/AVC tools.
文摘Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular LDPC codes with Unequal Error Protection (UEP)property is designed in this letter. Simulation results show that the transmission quality of the image may be effectively improved with this class of irregular LDPC code.
基金supported by the Dr.and Mrs.Sui Kau Chan donation grant for sports training and rehabilitation held by Chetwyn C.H.Chan and Amy S.N.Fuand by an internal grant awarded to Chetwyn C.H.Chan by The Hong Kong Polytechnic University
文摘Purpose： This study aimed to investigate the construct of external visual imagery （EVI） vs. internal visual imagery （IV/） by comparing the athletes＇ imagery ability with their levels of skill and types of sports. Methods： Seventy-two young athletes in open （n = 45） or closed （n = 27） sports and with different skill levels completed 2 custom-designed tasks. The EVI task involved the subject generating and visualizing the rotated images of different body parts, whereas the IVI task involved the subject visualizing himself or herself performing specific movements. Results： The significant Skill-Level x Sport Type interactions for the EVI task revealed that participants who specialized in open sports and had higher skill-levels had a higher accuracy rate as compared to the other subgroups. For the IVI task, the differences between the groups were less clear： those with higher skill-levels or open sports had a higher accuracy rate than those with lower skill-levels or closed sports. Conclusion： EVI involves the visualization of others and the environment, and would be relevant to higher skill-level athletes who engage in open sports. IVI, in contrast, tends to be more self-oriented and would be relevant for utilization by higher skill-level athletes regardless of sport type.
基金Supported by the Fujian Science and Technology Project(No.2006I0018,No.2009I0014)
文摘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.
