As a promising technique to enhance the spatial reso- lution of remote sensing imagery, sub-pixel mapping is processed based on the spatial dependence theory with the assumption that the land cover is spatially depend...As a promising technique to enhance the spatial reso- lution of remote sensing imagery, sub-pixel mapping is processed based on the spatial dependence theory with the assumption that the land cover is spatially dependent both within pixels and be- tween them. The spatial attraction is used as a tool to describe the dependence. First, the spatial attractions between pixels, sub- pixel/pixel spatial attraction model （SPSAM）, are described by the modified SPSAM （MSPSAM） that estimates the attractions accord- ing to the distribution of sub-pixels within neighboring pixels. Then a mixed spatial attraction model （MSAM） for sub-pixel mapping is proposed that integrates the spatial attractions both within pix- els and between them. According to the expression of the MSAM maximumising the spatial attraction, the genetic algorithm is em- ployed to search the optimum solution and generate the sub-pixel mapping results. Experiments show that compared with SPSAM, MSPSAM and pixel swapping algorithm modified by initialization from SPSAM （MPS）, MSAM can provide higher accuracy and more rational sub-pixel mapping results.展开更多
Digital image encryption based on Joseph circle and Chaotic system has become a hot spot in the research of image encryption. An encryption algorithm based on improved Josephus loop and logistic mapping is proposed to...Digital image encryption based on Joseph circle and Chaotic system has become a hot spot in the research of image encryption. An encryption algorithm based on improved Josephus loop and logistic mapping is proposed to scrambling blocks in this paper. At first, the original image is scrambled by using logistic mapping to obtain the encrypted image, and then the encrypted image is divided into many blocks. Finally, the position of the blocked image is scrambled by using the improved Josephus ring to get the encrypted image. According to the experiments, the information entropy of the encrypted image reaches 7.99 and the adjacent correlations in three directions are within ±0.1. The experimental results show that the proposed algorithm has advantages of large key space, high key sensitivity and can effectively resist the attacks of statistical analysis and gray value analysis. It has good encryption effect on digital image encryption.展开更多
In this paper, a novel image encryption algorithm is presented based on self-cited pixel summation. With the classical mechanism of permutation plus diffusion, a pixel summation of the plain image is employed to make ...In this paper, a novel image encryption algorithm is presented based on self-cited pixel summation. With the classical mechanism of permutation plus diffusion, a pixel summation of the plain image is employed to make a gravity influence on the pixel positions in the permutation stage. Then, for each pixel in every step of the diffusion stage, the pixel summation calculated from the permuted image is updated. The values from a chaotic sequence generated by an intertwining logistic map are selected by this summation. Consequently, the keystreams generated in both stages are dependent on both the plain image and the permuted image. Because of the sensitivity of the chaotic map to its initial conditions and the plain-imagedependent keystreams, any tiny change in the secret key or the plain image would lead to a significantly different cipher image. As a result, the proposed encryption algorithm is immune to the known plaintext attack（KPA） and the chosen plaintext attack（CPA）. Moreover, experimental simulations and security analyses show that the proposed permutationdiffusion encryption scheme can achieve a satisfactory level of security.展开更多
During this research work we developed another approach to digital mapping using the pixelation technic. This unprecedented digital mapping of the basin MSGBC in Senegal required the compilation of numerous geological...During this research work we developed another approach to digital mapping using the pixelation technic. This unprecedented digital mapping of the basin MSGBC in Senegal required the compilation of numerous geological data consisting of seismic lines and oil and hydraulic log reports. These spatial reference data include geological information from the surface to the top of the Campanian. The mapped terrains are composed of the Post-Paleocene Complex (PPC), the Paleocene, the Maastrichtian, and the Campanian. The nearest neighbor method has been used to establish the spatial distribution of the different geological formations. Histograms of values were used to determine the confidence intervals of the mapping. They were used to locate areas of low relative error and to apply the 3D digital mapping technique. For instance, Diender Guedj has been mapped at 1:25,000. The result of this mapping is extracted and processed using the DBMS (MySQL) software. The latter allowed both to determine Paleocene gab and update data. And then the database is processed. The programming languages PHP and Javascript have been used to simulate a website.展开更多
基金supported by the National Natural Science Foundation of China (60802059)the Foundation for the Doctoral Program of Higher Education of China (200802171003)
文摘As a promising technique to enhance the spatial reso- lution of remote sensing imagery, sub-pixel mapping is processed based on the spatial dependence theory with the assumption that the land cover is spatially dependent both within pixels and be- tween them. The spatial attraction is used as a tool to describe the dependence. First, the spatial attractions between pixels, sub- pixel/pixel spatial attraction model （SPSAM）, are described by the modified SPSAM （MSPSAM） that estimates the attractions accord- ing to the distribution of sub-pixels within neighboring pixels. Then a mixed spatial attraction model （MSAM） for sub-pixel mapping is proposed that integrates the spatial attractions both within pix- els and between them. According to the expression of the MSAM maximumising the spatial attraction, the genetic algorithm is em- ployed to search the optimum solution and generate the sub-pixel mapping results. Experiments show that compared with SPSAM, MSPSAM and pixel swapping algorithm modified by initialization from SPSAM （MPS）, MSAM can provide higher accuracy and more rational sub-pixel mapping results.
文摘Digital image encryption based on Joseph circle and Chaotic system has become a hot spot in the research of image encryption. An encryption algorithm based on improved Josephus loop and logistic mapping is proposed to scrambling blocks in this paper. At first, the original image is scrambled by using logistic mapping to obtain the encrypted image, and then the encrypted image is divided into many blocks. Finally, the position of the blocked image is scrambled by using the improved Josephus ring to get the encrypted image. According to the experiments, the information entropy of the encrypted image reaches 7.99 and the adjacent correlations in three directions are within ±0.1. The experimental results show that the proposed algorithm has advantages of large key space, high key sensitivity and can effectively resist the attacks of statistical analysis and gray value analysis. It has good encryption effect on digital image encryption.
基金supported by the National Natural Science Foundation of China(Grant Nos.61602124,61273021,11526057,and 11301091)the Natural Science Foundation of Guangdong Province,China(Grant Nos.2016A030310333,2015A030313614,and 2015A030313620)+3 种基金the Science & Technology Planning Projects of Zhanjiang City,China(Grant Nos.2015B01098 and 2015B01051)the Project Foundation of Chongqing Municipal Education Committee of China(Grant No.KJ1500501)the Program for Scientific Research Start-up Funds of Guangdong Ocean University of Chinathe Special Funding Program for Excellent Young Scholars of Guangdong Ocean University of China
文摘In this paper, a novel image encryption algorithm is presented based on self-cited pixel summation. With the classical mechanism of permutation plus diffusion, a pixel summation of the plain image is employed to make a gravity influence on the pixel positions in the permutation stage. Then, for each pixel in every step of the diffusion stage, the pixel summation calculated from the permuted image is updated. The values from a chaotic sequence generated by an intertwining logistic map are selected by this summation. Consequently, the keystreams generated in both stages are dependent on both the plain image and the permuted image. Because of the sensitivity of the chaotic map to its initial conditions and the plain-imagedependent keystreams, any tiny change in the secret key or the plain image would lead to a significantly different cipher image. As a result, the proposed encryption algorithm is immune to the known plaintext attack（KPA） and the chosen plaintext attack（CPA）. Moreover, experimental simulations and security analyses show that the proposed permutationdiffusion encryption scheme can achieve a satisfactory level of security.
文摘During this research work we developed another approach to digital mapping using the pixelation technic. This unprecedented digital mapping of the basin MSGBC in Senegal required the compilation of numerous geological data consisting of seismic lines and oil and hydraulic log reports. These spatial reference data include geological information from the surface to the top of the Campanian. The mapped terrains are composed of the Post-Paleocene Complex (PPC), the Paleocene, the Maastrichtian, and the Campanian. The nearest neighbor method has been used to establish the spatial distribution of the different geological formations. Histograms of values were used to determine the confidence intervals of the mapping. They were used to locate areas of low relative error and to apply the 3D digital mapping technique. For instance, Diender Guedj has been mapped at 1:25,000. The result of this mapping is extracted and processed using the DBMS (MySQL) software. The latter allowed both to determine Paleocene gab and update data. And then the database is processed. The programming languages PHP and Javascript have been used to simulate a website.
