提出了一种结合信息伪装和隐藏技术来保护数字高程模型(digital elevation model,简称DEM)数据的方法,保证了DEM数据的安全传输和存储.设计了DEM数据极低比特率压缩方法,压缩数据隐藏在伪装数据中.应用带参数整数小波变换,提出可嵌入隐藏信息的小波系数集合生成方法.扩展了只针对图像的基于视觉系统(human visual system,简称HVS)小波域量化噪声的视觉权重(just noticeable distortion,简称JND)分析方法,使其适用于DEM数据,自适应地确定信息隐藏的强度.该方法可同时保护两组DEM地形数据.应用Rabin方法生成单向Hash函数.算法可以完全公开.
An information disguising and hiding technique is used to protect DEM (digital elevation model) data for store and transformation in this paper. A method is designed to compress the DEM data with a very low bit ratio which would be hidden in the disguised data. The integer wavelet with parameter is used, and a wavelet coefficients set which can embed the information is built. This paper expands the just noticeable distortion (JND) analysis based on the human visual system (HVS) to apply it in the,DEM data. Furthermore this paper constructs Hash one-way by the Rabin method, and the algorithm can protect two groups of the DEM data at a time and be public.