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篇目详细内容 |
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【篇名】 |
A pyramid-based approach to visual exploration of a large volume of vehicle trajectory data |
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【刊名】 |
Frontiers of Earth Science |
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【刊名缩写】 |
Front. Earth Sci |
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【ISSN】 |
2095-0195 |
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【EISSN】 |
2095-0209 |
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【DOI】 |
10.1007/s11707-012-0333-z |
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【出版社】 |
Higher Education Press and Springer-Verlag Berlin
Heidelberg |
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【出版年】 |
2012 |
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【卷期】 |
6
卷4期 |
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【页码】 |
345-353
页,共
9
页 |
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【作者】 |
Jing SUN;
Xiang LI;
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【关键词】 |
large volumes of trajectory data; visualization; grid-based indexing structure; image pyramid |
【摘要】 |
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Advances in positioning and wireless communicating technologies make it possible to collect large volumes of trajectory data of moving vehicles in a fast and convenient fashion. These data can be applied to traffic studies. Behind this application, a methodological issue that still requires particular attention is the way these data should be spatially visualized. Trajectory data physically consists of a large number of positioning points. With the dramatic increase of data volume, it becomes a challenge to display and explore these data. Existing commercial software often employs vector-based indexing structures to facilitate the display of a large volume of points, but their performance downgrades quickly when the number of points is very large, for example, tens of millions. In this paper, a pyramid-based approach is proposed. A pyramid method initially is invented to facilitate the display of raster images through the tradeoff between storage space and display time. A pyramid is a set of images at different levels with different resolutions. In this paper, we convert vector-based point data into raster data, and build a grid-based indexing structure in a 2D plane. Then, an image pyramid is built. Moreover, at the same level of a pyramid, image is segmented into mosaics with respect to the requirements of data storage and management. Algorithms or procedures on grid-based indexing structure, image pyramid, image segmentation, and visualization operations are given in this paper. A case study with taxi trajectory data in Shanghai is conducted. Results demonstrate that the proposed method outperforms the existing commercial software. |
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