With the rapid development of information network,the computing resources and storage capacity of ordinary users cannot meet their needs of data processing.The emergence of cloud computing solves this problem but brin...With the rapid development of information network,the computing resources and storage capacity of ordinary users cannot meet their needs of data processing.The emergence of cloud computing solves this problem but brings data security problems.How to manage and retrieve ciphertext data effectively becomes a challenging problem.To these problems,a new image retrieval method in ciphertext domain by block image encrypting based on Paillier homomophic cryptosystem is proposed in this paper.This can be described as follows:According to the Paillier encryption technology,the image owner encrypts the original image in blocks,obtains the image in ciphertext domain,then passes it to the third party server.The server calculates the difference histogram of the image in ciphertext domain according to the public key and establishes the index database.The user passes the retrieved image to the server.The server computes the differential histogram of the retrieved image by public key.Then,compares the similarity of it with the histogram in index database and selects larger similarity images in ciphertext and send them to the user.The user obtains the target image with the private key.The experimental results show that the method is feasible and simple.展开更多
This essay concentrates on two key procedures of image mosaic--image registration and imagefusion.Becauseof the character of geometric transformation invariance of edge points, wecalculate the angle difference of the ...This essay concentrates on two key procedures of image mosaic--image registration and imagefusion.Becauseof the character of geometric transformation invariance of edge points, wecalculate the angle difference of the direction vector ofedge points in different images anddraw an angle difference histogramto adjust the rotationproblem. Through this way, algorithm based on gray information is expandedandcan be used in images withdisplacementand rotation. Inthe term of image fusion, wavelet multi-scale analysis is used to fuse spliced images. In order to choose the best method of imagefusion,weevaluate the results of different methods of image fusion by cross entropy.展开更多
Recently, an edge adaptive image stegano- graphic method based on least significant bit （LSB） matching revisited （EA-LSBMR） has been proposed, which holds good visual quality and proper security under appropriate ...Recently, an edge adaptive image stegano- graphic method based on least significant bit （LSB） matching revisited （EA-LSBMR） has been proposed, which holds good visual quality and proper security under appropriate embedding rates. However, from the extensive experiments to EA-LSBMR, we find that the discrete Fourier transform （DFT） spectrum of pixelpairs differences histogram still reveals the presence of a secret message even in a low embedding rate. To enhance the security, a modified scheme is proposed in this paper, which can defeat the above-mentioned analysis and keep the visual quality better than EA-LSBMR in higher embedding rates. Experimental results using a latest universal steganalysis method have demonstrated the proposed method＇s good performance.展开更多
基金This work was supported in part by the Natural Science Foundation of China(No.61772234,61272414).
文摘With the rapid development of information network,the computing resources and storage capacity of ordinary users cannot meet their needs of data processing.The emergence of cloud computing solves this problem but brings data security problems.How to manage and retrieve ciphertext data effectively becomes a challenging problem.To these problems,a new image retrieval method in ciphertext domain by block image encrypting based on Paillier homomophic cryptosystem is proposed in this paper.This can be described as follows:According to the Paillier encryption technology,the image owner encrypts the original image in blocks,obtains the image in ciphertext domain,then passes it to the third party server.The server calculates the difference histogram of the image in ciphertext domain according to the public key and establishes the index database.The user passes the retrieved image to the server.The server computes the differential histogram of the retrieved image by public key.Then,compares the similarity of it with the histogram in index database and selects larger similarity images in ciphertext and send them to the user.The user obtains the target image with the private key.The experimental results show that the method is feasible and simple.
基金Supported by National Natural Science Foundation of China(No.11001017)
文摘This essay concentrates on two key procedures of image mosaic--image registration and imagefusion.Becauseof the character of geometric transformation invariance of edge points, wecalculate the angle difference of the direction vector ofedge points in different images anddraw an angle difference histogramto adjust the rotationproblem. Through this way, algorithm based on gray information is expandedandcan be used in images withdisplacementand rotation. Inthe term of image fusion, wavelet multi-scale analysis is used to fuse spliced images. In order to choose the best method of imagefusion,weevaluate the results of different methods of image fusion by cross entropy.
基金supported in part by the National Science Foundation of China for Distinguished Young Scholars under Grant No. 61025013Sino-Singapore JRP under Grant No. 2010DFA11010+1 种基金National NSF of China under Grant No. 61073159Fundamental Research Funds for the Central Universities under Grant No. 2009JBZ006
文摘Recently, an edge adaptive image stegano- graphic method based on least significant bit （LSB） matching revisited （EA-LSBMR） has been proposed, which holds good visual quality and proper security under appropriate embedding rates. However, from the extensive experiments to EA-LSBMR, we find that the discrete Fourier transform （DFT） spectrum of pixelpairs differences histogram still reveals the presence of a secret message even in a low embedding rate. To enhance the security, a modified scheme is proposed in this paper, which can defeat the above-mentioned analysis and keep the visual quality better than EA-LSBMR in higher embedding rates. Experimental results using a latest universal steganalysis method have demonstrated the proposed method＇s good performance.
