摘要
随着地理信息系统的不断发展,在军用、民用等领域已经积累了海量栅格数据,对存储容量的需求也随之快速增长。针对如何降低存储体积这一问题,该文提出了一种保存高程数据距离信息的无损压缩算法。首先,选择若干小于原始数据占用比特个数的数值,并计算其阈值;然后,计算最大高程距离所属的阈值范围以及阈值上限对应的比特数m;接着,将高程值与最小值的距离逐一左移m个比特进行保存;进一步优化算法,针对等分后的高程瓦片小块采用上述算法进行压缩;最后,选取压缩率最高的压缩数据。实验结果表明:针对瓦片小块利用该文无损压缩算法,能有效降低高程数据的存储体积。
With the development of GIS,there are massive raster data in military and civilian fields,which demand increasing storage.Aimed at how to reduce the elevation-raster data storage,this paper provides a lossless compression algorithm by keeping the data distances.Firstly,number of bits smaller than the bits used for keeping elevation data are chosen,with thresholds are calculated;secondly,the m-bit is calculated according to upper limit of the threshold rang to which the maximum distance belongs;thirdly,other distances calculated according to the minimum elevation are kept within m bits in turn;this paper optimizes the algorithm by compressing the elevation tile blocks;finally,this paper selects the compressed data with the highest compression ratio.The result shows that the storage of elevation-raster data can be reduced by using the lossless algorithm to compress the elevation tile blocks.
作者
刘辰炜
孙耀宗
Liu Chen-wei;Sun Yao-zong(The 28th Research Institute of China Electronics Technology Group Corporation,Jiangsu Nanjing 210007)
出处
《电子质量》
2019年第11期1-4,8,共5页
Electronics Quality
关键词
高程栅格数据
无损压缩
比特
阈值
瓦片分块
elevation-raster data
lossless compression
bit
threshold
tile block
作者简介
刘辰炜(1987-),男,工程师,硕士,主要研究方向为地理信息系统。E-mail:lcw_business@163.com;孙耀宗(1986-),男,工程师,硕士,主要研究方向为地理信息系统。
