Gaussian projection pdf map seamless splicing display method across frames

Abstract

The invention discloses a Gaussian projected PDF map cross-panel seamless splicing display method: the PDF page of the PDF map product file is rotated and preprocessed to obtain a Gaussian projected PDF map file for display; the same Gaussian projected band Calculate the inner contour polygon of Gaussian projection coordinates for each Gaussian projection PDF map file with the same scale for display, and build a map index; use the index file to initialize the PDF map display; display a single-panel Gaussian projection PDF map; Displays PDF maps of multiple Gaussian projections across the frame. The present invention realizes the seamless connection of square grids of all map frames in the same Gaussian projection zone, realizes the seamless splicing and display of PDF maps of Gaussian projections of adjacent map frames, and expands the use range of PDF maps. The independent application mode is upgraded to the seamless splicing application mode of multiple maps, so that the use of PDF maps is no longer limited by the size of the map, which greatly improves the user experience.

Description

technical field [0001] The invention belongs to the technical field of PDF map display, in particular to a Gaussian projected PDF map cross-frame seamless splicing display method. Background technique [0002] PDF map is a new type of map product that stores geospatial information in accordance with the PDF format standard. It has the characteristics of beautiful graphics, element layering, coordinate measurement, attribute query, and spatial analysis. It is an ideal for integrated storage and distribution of maps and geographic information. solution. The PDF map is an important achievement of domestic research on GeospatialPDF. The applicant's research team began to study the PDF map in 2006, which is almost parallel to the foreign GeoPDF in terms of time. GeoPDF is a registered trademark of TerraGo. It is a map and image product created by TerraGo software. It is the best solution for Geospatial PDF in the industry and has been recommended by OGC as a map coding standard....

AI Technical Summary

Problems solved by technology

PDF map files can be opened and used by commonly used PDF reader software. However, the user's browsing of the map can only be limited to a single map, and it is impossible to realize seamless roaming across map frames and regions. This is the use of PDF maps. a big flaw

The same is true for the use of GeoPDF. When you need to browse other frames adjacent to the current frame, you can only link to the GeoPDF file where the desired frame is located by manually opening or hyperlinking. The edges of adjacent frames cannot be spliced. and display together on the screen

However, with the popularization of maps, it is a normal demand for users to use maps across maps and regions. It is a very bad experience for PDF map users to get the whole picture of the area without the complete spatial form of the ground objects.

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