Information Disguising for Digital Elevation Model Data via Empirical Mode Decomposition

A novel information disguising method based on empirical mode decomposition is proposed.The pseudorandom sequence controlled by seeds of the SHA-256 one-way hash function is generated;and digital elevation model data for disguising is achieved by decomposing the expanded pseudorandom sequence via empirical mode decomposition(EMD).The high vision fraudulence is obtained for disguised DEM data.Furthermore,the concepts of the histogram for DEM data is also proposed;and the watermarking was reversibly embedded in the disguised DEM data by modifying its histogram.The disguised DEM data can be completely reconstructed without any distortion from the marked data after the watermark has been extracted.The secret DEM data can be recovered via the seed.The proposed algorithm owns high security.