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A Lossless Compression Method of Road Network Trajectories

A lossless compression and trajectory technology, applied in the field of trajectory calculation, which can solve the problem that the trajectory cannot be completely restored.

Inactive Publication Date: 2016-09-28
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Obviously, this technique for trajectory compression is a lossy compression, and the compressed trajectory cannot be completely restored

Method used

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  • A Lossless Compression Method of Road Network Trajectories
  • A Lossless Compression Method of Road Network Trajectories

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Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0035] The present invention will be further described below in conjunction with specific examples.

[0036] 1. Compute the shortest path between any road segments:

[0037] For example figure 1 For each road segment in the road network, use the Dijkstra algorithm to calculate the shortest path length from this road segment to all other road segments in the road network, and calculate the shortest path table SP end .

[0038] The calculated shortest path table is as follows (1)

[0039]

[0040] Table 1)

[0041] 2. Add the first section of the sequence to the compression result, and cut off the longest shortest path from the head of the track: from the head of the track, divide a subsequence that is the longest and coincides with the shortest path. Specifically, the operation is as follows :

[0042] (a) From the head segment of the remaining trajectory e 15 start scanning, iee s for e 15 ;

[0043] (b) will e 15 Add to the tail of the compressed result track...

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Abstract

The invention belongs to the technical field of track calculation, and particularly relates to a lossless compression method of road network track. The lossless compression method of the road network track comprises the steps that the shortest path between any road segments is calculated and stored in a database according to a road network; a first road segment of the road network track is selected, and the road network track is scanned backwards in sequence until the whole track is scanned or a passed subsequence and the shortest path between head and tail road segments of subsequence are inconsistent; the road network track is scanned again from the road segment not meeting requirements; the steps are repeated until the scanning of the track is finished; the first road segment in each segment and the final road segment in each sequence are stored as compression results, and lossless compression can be carried out on the results according to an inverse process of the steps.

Description

technical field [0001] The invention belongs to the technical field of trajectory calculation, and in particular relates to a lossless compression method of road network trajectory. Background technique [0002] Trajectory calculation is a technical field emerging under the background of a large amount of user trajectory data with the popularization of GPS user location acquisition equipment and the popularity of applications such as location check-in. The technology in the field of trajectory calculation has the characteristics of strong pertinence and good practicability. Specific to the field of trajectory compression, trajectory compression technology can make full use of the characteristics of the trajectory itself compared with the universal data compression technology, and the compression effect is much better than the universal data compression method. It can effectively reduce computer processing load and data storage and transmission overhead, and improve the spee...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H03M7/30
Inventor 孙未未宋壬初
Owner FUDAN UNIV