Objectives Real-time visualization of large-scale geographic vector data is a hot and difficult topic in the field of geographic information science. In the current research, display-driven computing method (DisDC) is insensitive to data scale and can support real-time visualization of large-scale geographic vector data. However, with the growth of data scale, the index construction time and the index size of the DisDC visualization method greatly increase in data preprocessing, which greatly affects the practicability of the method.
Methods To fill the gap, a fast indexing technique based on DisDC is proposed. Rapid construction of tile-quadtree index (TQ-tree) based on quadtree recursive division of global geographic range in the pre-processing stage, in TQ-tree, the alignment of nodes and tiles/pixels are realized by encoding. In the visualization stage, according to the process of DisDC, the pixel is taken as the calculation unit to determine whether the corresponding node of the pixel in TQ-tree exists, and the pixel value can be quickly calculated to generate the final display effect.
Results Experimental results show that the proposed technique has shorter index construction time and smaller index size, and the visualization efficiency outperforms the existing DisDC visualization methods.
Conclusions The Method can support real-time visualization of multi-billion vector elements more quickly.
DownLoad: