Journal of Computer Applications ›› 2017, Vol. 37 ›› Issue (7): 1911-1915.DOI: 10.11772/j.issn.1001-9081.2017.07.1911

Previous Articles     Next Articles

Parallel algorithm for hillshading under multi-core computing environment

HAN Litao1,2, LIU Hailong1, KONG Qiaoli1,3, YANG Fanlin1,2   

  1. 1. College of Geomatics, Shandong University of Science and Technology, Qingdao Shandong 266590, China;
    2. Key Laboratory of Surveying and Mapping Technology on Island and Reed, National Administration of Surveying, Mapping and Geoinformation(Shandong University of Science and Technology), Qingdao Shandong 266590, China;
    3. Engineering Laboratory of Spatial Information Technology of Highway Geological Disaster Early Warning in Hunan Province(Changsha University of Science & Technology), Changsha Hunan 410004, China
  • Received:2017-02-08 Revised:2017-03-06 Online:2017-07-10 Published:2017-07-18
  • Supported by:
    his work is partially supported by the National Natural Science Foundation of China (41201381, 41376108), the Open Fund of Engineering Laboratory of Spatial Information Technology of Highway Geological Disaster Early Warning in Hunan Province (kfj150605).

基于多核计算环境的地貌晕渲并行算法

韩李涛1,2, 刘海龙1, 孔巧丽1,3, 阳凡林1,2   

  1. 1. 山东科技大学 测绘科学与工程学院, 山东 青岛 266590;
    2. 海岛(礁)测绘技术国家测绘地理信息局重点实验室(山东科技大学), 山东 青岛 266590;
    3. 公路地质灾变预警空间信息技术湖南省工程实验室(长沙理工大学), 长沙 410004
  • 通讯作者: 韩李涛
  • 作者简介:韩李涛(1978-),男,山东菏泽人,副教授,博士,主要研究方向:虚拟地理环境、空间信息可视化;刘海龙(1995-),男,山东菏泽人,硕士研究生,主要研究方向:地理信息系统;孔巧丽(1979-),女,山东菏泽人,讲师,博士,主要研究方向:全球定位与导航;阳凡林(1974-),男,湖北荆州人,教授,博士,主要研究方向:海洋测绘、海洋GIS。
  • 基金资助:
    国家自然科学基金资助项目(41201381,41376108);公路地质灾变预警空间信息技术湖南省工程实验室开放基金资助项目(kfj150605)。

Abstract: Most of the exiting hillshading algorithms are implemented based on single-core single-thread programming model, which makes them have lower computational efficiency. To solve this problem, an improved algorithm for parallelizing the existing hillshading algorithms based on multi-core programming model was proposed. Firstly, the original Digital Elevation Model (DEM) data were divided into several data blocks by grid segmentation. Secondly, these data blocks were shaded in parallel using the class Parallel under the .Net environment to generate shaded image of each block. Finally, the shaded images were spliced into a complete hillshading image. The experimental results show that the calculation efficiency of the improved parallelized algorithm is obviously higher than that of the existing shading algorithms based on single-core single-thread programming, and there is an approximate linear growth relation between the number of the involved cores and the shading efficiency. Additionally, it is also found that the three dimensional and realistic effect of the hillshading image is extremely relevant to the parameter setting of the light source.

Key words: multi-core environment, Digital Elevation Model (DEM), hillshading, parallel computing, data segmentation, image mosaic

摘要: 针对现有地貌晕渲算法多是基于单核单线程编程模式从而导致计算效率较低的问题,提出利用多核并行计算模式对现有地貌晕渲算法进行并行化改进。首先,通过格网分割方式对原始数字高程模型(DEM)数据进行分割从而实现数据分块;其次,利用.NET环境下的Parallel类对分块数据进行并行晕渲处理,得到各个分块数据的晕渲结果;最后,对各个分块数据的晕渲图像进行拼接,从而得到完整的地貌晕渲图像。实验结果表明:并行化改进算法的计算效率明显高于现有单核单线程地貌晕渲算法,且参与计算核数与晕渲效率基本上呈线性增长关系;同时,分析发现地貌晕渲的立体真实感与光源参数的设置极其相关。

关键词: 多核环境, 数字高程模型, 地貌晕渲, 并行计算, 数据分块, 图像拼接

CLC Number: