Grid DEM (digital elevation model) blind watermark method resistant to elevation translation and clipping attack

Abstract

Elevation translation and clipping are common attacking manners specific to DEM data watermark, and the invention provides a grid DEM (digital elevation model) blind watermark method resistant to elevation translation and clipping attack effectively. The method takes account of the characteristics of DEM data, carries out spread spectrum processing to an original watermark, makes the original watermark and an elevation difference value form a mapping relation, utilizes the feature that the elevation difference value of adjacent grids does not change in an elevation translation attack, embeds the bitwise of the watermark subjected to spread spectrum into the elevation difference value in a quantification manner, and apportions the expansive difference value to back single bit of the adjacent elevations. The watermark method has good invisibility, has a relatively small influence on the DEM data accuracy and application accuracy, and has good robustness in resisting the elevation translation and the clipping attack.

Description

technical field [0001] The invention belongs to the technical field of cartography and geographic information science, and relates to a blind watermarking method aimed at resisting elevation translation and clipping attacks for regular grid DEM data. Background technique [0002] Digital elevation model (Digital Elevation Model, DEM) is an important part of geospatial data, and has been widely used in surveying and mapping, geology, mine engineering, battlefield simulation and other fields. However, while the digital form of DEM brings convenience to terrain simulation analysis, it is easier to tamper and infringe because of its easy storage, modification, and dissemination characteristics. The resulting DEM copyright disputes are becoming more and more serious. Therefore, how to share DEM data reasonably and at the same time effectively protect the owner's copyright interests has become an urgent and realistic problem. [0003] Digital watermarking technology plays an impo...

AI Technical Summary

Problems solved by technology

In the research of DEM data watermarking technology, elevation translation and cropping are the most common attack methods against DEM data watermarking, and most methods are less robust in resisting elevation translation and cropping attacks at the same time.

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