Pan-sharpening is a process of obtaining a high spatial and spectral multispectral image(HMS)by combining a low-resolution multispectral image(LMS)with a high-resolution panchromatic image(PAN).In this paper,a pan-sha...Pan-sharpening is a process of obtaining a high spatial and spectral multispectral image(HMS)by combining a low-resolution multispectral image(LMS)with a high-resolution panchromatic image(PAN).In this paper,a pan-sharpening method called PAIHS is proposed,which is based on adaptive intensity-hue-saturation(AIHS)transformation,variational pan-sharpening framework and the two fidelity hypotheses.The suitable objective function is established and optimized by adopting particle swarm optimization(PSO)to obtain the optimal control parameters and minimum value.This value corresponds to the best pan-sharpening quality.The experimental results show that the proposed method has high efficiency and reliability,and the obtained performance index is superior to the four mainstream pan-sharpening methods.展开更多
Objective and accurate classification model or method of cloud image is a prerequisite for accurate weather monitoring and forecast.Thus safety of aircraft taking off and landing and air flight can be guaranteed.Thres...Objective and accurate classification model or method of cloud image is a prerequisite for accurate weather monitoring and forecast.Thus safety of aircraft taking off and landing and air flight can be guaranteed.Thresholding is a kind of simple and effective method of cloud classification.It can realize automated ground-based cloud detection and cloudage observation.The existing segmentation methods based on fixed threshold and single threshold cannot achieve good segmentation effect.Thus it is difficult to obtain the accurate result of cloud detection and cloudage observation.In view of the above-mentioned problems,multi-thresholding methods of ground-based cloud based on exponential entropy/exponential gray entropy and uniform searching particle swarm optimization(UPSO)are proposed.Exponential entropy and exponential gray entropy make up for the defects of undefined value and zero value in Shannon entropy.In addition,exponential gray entropy reflects the relative uniformity of gray levels within the cloud cluster and background cluster.Cloud regions and background regions of different gray level ranges can be distinguished more precisely using the multi-thresholding strategy.In order to reduce computational complexity of original exhaustive algorithm for multi-threshold selection,the UPSO algorithm is adopted.It can find the optimal thresholds quickly and accurately.As a result,the real-time processing of segmentation of groundbased cloud image can be realized.The experimental results show that,in comparison with the existing groundbased cloud image segmentation methods and multi-thresholding method based on maximum Shannon entropy,the proposed methods can extract the boundary shape,textures and details feature of cloud more clearly.Therefore,the accuracies of cloudage detection and morphology classification for ground-based cloud are both improved.展开更多
基金National Natural Science Foundation of China(No.61703278)。
文摘Pan-sharpening is a process of obtaining a high spatial and spectral multispectral image(HMS)by combining a low-resolution multispectral image(LMS)with a high-resolution panchromatic image(PAN).In this paper,a pan-sharpening method called PAIHS is proposed,which is based on adaptive intensity-hue-saturation(AIHS)transformation,variational pan-sharpening framework and the two fidelity hypotheses.The suitable objective function is established and optimized by adopting particle swarm optimization(PSO)to obtain the optimal control parameters and minimum value.This value corresponds to the best pan-sharpening quality.The experimental results show that the proposed method has high efficiency and reliability,and the obtained performance index is superior to the four mainstream pan-sharpening methods.
基金Supported by the National Natural Science Foundation of China(60872065)the Open Foundation of Key Laboratory of Meteorological Disaster of Ministry of Education at Nanjing University of Information Science & Technology(KLME1108)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Objective and accurate classification model or method of cloud image is a prerequisite for accurate weather monitoring and forecast.Thus safety of aircraft taking off and landing and air flight can be guaranteed.Thresholding is a kind of simple and effective method of cloud classification.It can realize automated ground-based cloud detection and cloudage observation.The existing segmentation methods based on fixed threshold and single threshold cannot achieve good segmentation effect.Thus it is difficult to obtain the accurate result of cloud detection and cloudage observation.In view of the above-mentioned problems,multi-thresholding methods of ground-based cloud based on exponential entropy/exponential gray entropy and uniform searching particle swarm optimization(UPSO)are proposed.Exponential entropy and exponential gray entropy make up for the defects of undefined value and zero value in Shannon entropy.In addition,exponential gray entropy reflects the relative uniformity of gray levels within the cloud cluster and background cluster.Cloud regions and background regions of different gray level ranges can be distinguished more precisely using the multi-thresholding strategy.In order to reduce computational complexity of original exhaustive algorithm for multi-threshold selection,the UPSO algorithm is adopted.It can find the optimal thresholds quickly and accurately.As a result,the real-time processing of segmentation of groundbased cloud image can be realized.The experimental results show that,in comparison with the existing groundbased cloud image segmentation methods and multi-thresholding method based on maximum Shannon entropy,the proposed methods can extract the boundary shape,textures and details feature of cloud more clearly.Therefore,the accuracies of cloudage detection and morphology classification for ground-based cloud are both improved.
