Electronic chart displaying method based on tile technology

Abstract

The invention discloses an electronic chart displaying method based on a tile technology. The method comprises the steps that firstly, a server segments multiple electronic charts which have differentmeasuring scales into square lattice pictures with the fixed size according to a pyramid hierarchical model, and these lattice pictures are chart tiles; then, the server codes the map tiles accordingto the hierarchy and the coordinate information of a pyramid where the tiles are located, and stores the tiles according to coding information of the chart tiles; then, a client side determines a geographical coordinate range displayed by a view window according to a coordinate conversion formula, converts the geographical coordinate range into a serial number range of the chart tiles, and requests the chart tiles from the server according to the serial numbers of the tiles; finally, the client side splices the obtained electronic chart tiles into large textures, and displays the large textures on a screen in a rendering mode through an OpenGL texture mapping technology. By means of the electronic chart displaying method based on the tile technology, the displaying efficiency of the electronic charts is improved, and the application scene of the electronic chart is expanded.

Description

technical field [0001] The invention relates to an electronic chart display method based on tile technology. Background technique [0002] WebGIS (Web Map Information System) is the product of Internet (Internet) technology applied to GIS (Geographic Information System). Early WebGIS, such as WMS (Web Map Server network map service) using B / S (Browser / Server) architecture, its map rendering principle is that the server renders and draws pictures in real time, and then loads them into the browser for display. This rendering method inevitably increases the load on the server, and at the same time reduces the efficiency of the system for rendering maps. Google (Google) proposes that the tile map technology is stored on the server side in the form of pre-slicing (map tiles), and the client directly requests the server to access the map tiles, which effectively solves the problem of slow and inefficient traditional WebGIS map output. Tiling has become the most mainstream GIS fo...

AI Technical Summary

Problems solved by technology

This rendering method inevitably increases the load on the server, and at the same time reduces the efficiency of the system rendering maps

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