Fast Construction of Global Pyramids for Very Large Satellite Images
Fast Construction of Global Pyramids for Very Large Satellite Images
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DOI：
10.1111/tgis.12001
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发表时间：
2013-04
影响因子：
2.4
通讯作者：
Longgang Xiang;Jing Chen;J. Gong;Zhen Zeng
中科院分区：
文献类型：
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作者：
Longgang Xiang;Jing Chen;J. Gong;Zhen Zeng
卫星图像在最近流行的虚拟地球仪系统中起着至关重要的作用，因为它以直接和直观的方式提供与空间相关的信息。由于覆盖范围大、分辨率高或两者兼有，卫星图像的尺寸可能非常大，因此，作为虚拟地球仪核心数据结构的全球金字塔的构建如果设计不当将非常耗时。本文基于分而治之的思想，提出了一种高效的算法，称为CGP，用于构建全局金字塔，该算法只需对输入图像进行一次顺序扫描即可构建全局金字塔。通过分析CGP的空间复杂度，推导出CGP的内存最小金字塔等级，在该等级下，即使对于非常大的卫星图像，CGP的内存需求也被最小化到实用水平.本文还讨论了CGP的一种并行实现，它将CGP中的两个主要动作并行化，从而进一步提高了金字塔构造的性能。理论分析和实验结果表明，我们的方法优于其他方法，更重要的是，这种优势大大增加的输入图像的大小增加。
Satellite imagery plays a critical role in recent popular Virtual Globe systems since it delivers spatially‐related information in a direct and intuitive way. A satellite image may be very large in size due to large coverage, high resolution, or both, and therefore the construction of global pyramids, a core data structure of Virtual Globe, will be time‐consuming if designed improperly. This article, based on the idea of divide‐and‐conquer, proposes an efficient algorithm, termed CGP, for the Construction of Global Pyramids, which builds global pyramids with only a single sequential scan of input imagery. By analyzing the space complexity of CGP, the memory‐minimum pyramid level is derived, at which the memory requirement of CGP is minimized to a practical level, even for very large satellite images. This article also discusses a parallel implementation of CGP, which parallelizes the two main actions in CGP, thus further improving the pyramid construction performance. Both theoretical analysis and experimental results show that our approach outperforms other methods and, more importantly, this advantage increases considerably as the size of input imagery increases.