Xuchong Liu

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A disguise algorithm about DEM data is proposed in this paper, and it is based on matrix transformation and cryptographic algorithm. In this algorithm, a terrain is generated with a parametric surface, which is generated by the two element trigonometric function. The security communication of DEM data is realized through the discretization of the real DEM(More)
The conceptions of generalized grayscale and generalized histogram are introduced. A new lossless DEM data watermark sign based on directional wavelet and histogram shift has been developed. It can be used at integrity verification and lossless restoration. The watermark is generated by directional wavelet transformation and embedded by generalized(More)
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