Pyramid slicing method based on dynamic effect model (DEM) data

Abstract

The invention relates to a pyramid slicing method based on dynamic effect model (DEM) data. The pyramid slicing method based on the DEM data comprises the following steps: the first step is determining size of slicing and number of layers of the slicing, the second step is reading DEM data by using an open-source image reading device, the third step is judging whether existing size and number of layers of the slicing are suitable or not and determining the optimal number of layers L and combination number of initial pixel N , the fourth step is determining start-stop positions of a rank and a low of the DEM data needing to be read according to the existing number of layers, the fifth step is reading image pixel values in a partitioning mode according to the start-stop positions of the rank and the low, and carrying out data resampling of the data read, the sixth step is dividing the data according to the size of the slicing, outputting the slicing data, and naming each slicing datum in a standardization mode, and the seventh step is judging whether all layers are divided or not: if all layers are divided, the method is end; and if all layers are not divided, combination number of the initial pixel is modified and returning to the fourth step is needed. Compared with the prior art, the pyramid slicing method based on the DEM data is high in slicing efficiency, good in expandability and the like.

Description

technical field [0001] The invention relates to a map slicing method, in particular to a pyramid slicing method based on DEM data. Background technique [0002] DEM (Digital Elevation Model) is the basis of grid-based spatial analysis and has been widely used in various fields. However, the data size of DEM data will be significantly different with the range and accuracy, which will have a great impact on the display, reading, and analysis of the data during use, thus restricting the efficiency of use. How to achieve hierarchical cutting of DEM data and improve the efficiency of data use has become a common concern. [0003] Map slicing is currently the way most electronic maps implement map browsing. According to the specified size and slicing format, the map in a specific geographical range is cut into several rows and columns of square pictures. All map slices are stored on the server, and the pictures are processed. Quadtree encoding, the client requests different slic...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that it is synthesized at a size of 2x2 pixels each time, which affects the speed of data cutting, especially in the case of a large amount of map data and a large number of cutting levels; in addition, cutting The divided DEM data is the basis for users to conduct data analysis, and its size and series should take into account the actual needs, so that it is convenient for users to use.

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