KR20080071228A - Method for providing geographic information and system for providing geographic information service - Google Patents

Abstract

A method for providing a map and a system for providing a map service are provided to manage a grid index and cached map data efficiently by making an optimal grid size according to a scale level of the map requested from a user and managing grids of each scale level, and improve speed for reloading map data and displaying a map image by minimizing data retransmission with an optimal cache and prefetch mode. A web server(100) changes a grid size according to a scale level of a map requested from a user and provides map data of the requested map by each changed grid. A user terminal(200) receives the map data from the web server, and performs a cache or prefetch function for the map data received by each grid. The web server includes a map database(110) storing the map data of entire map and a map generator(130). The map generator generates the map data of each grid by changing a grid size of the map according to the scale level of the requested map and searching the map data for the requested map from the map database.

Description

Map providing method and map service providing system {METHOD FOR PROVIDING GEOGRAPHIC INFORMATION AND SYSTEM FOR PROVIDING GEOGRAPHIC INFORMATION SERVICE}

1 is a diagram showing the overall configuration of a map service providing system according to the present invention.

2 is a diagram illustrating the entire process of the map providing method of the web server provided by the present invention.

3 is a diagram illustrating a reference level and a grid size of the reference level for determining the grid size.

4 is a diagram illustrating a grid configuration according to a scale level below the reference level.

5 is a diagram showing a grid configuration according to a scale level exceeding a reference level.

FIG. 6 is a diagram illustrating an area quadrant tree configuration according to the scale level of FIG. 5.

<Explanation of symbols for main parts of the drawings>

100: web server 110: map database

130: map generation unit 200: user terminal

210: map display control unit 230: user interface

250: communication unit 270: memory

290: display unit

The present invention relates to a map providing method and a map service providing system. More particularly, in providing map information using a grid index, a map capable of managing grid indexes and cached map data can be more efficiently provided. It relates to a method and a map service providing system.

Geographic information system (GIS) is a system that provides geographic and map information that users need through querying and analyzing spatial data of relational database.

Such a geographic information system generally collects geographic data from public institutions or geographic information servers, converts it into an appropriate map image, and provides it to the user.

In the geographic information system, geographic data is stored and managed in a vector or raster format. When using a vector format, the geographic data can be stored in the form of coordinates (X, Y coordinates) and each terrain and feature can also be described as a series of X and Y coordinate points. Can be.

Since such a geographic information system is operated through a computer system and a network, the data size greatly influences the performance of the geographic information system.

In other words, in processing data related to basic search for a map in vector form, the processing time increases as the capacity of data increases, and as the load on the server increases, it causes many problems such as delay in response time in providing map services. .

When a user searches for a map and requests zooming and panning of the display map, the existing geoinformation system overlaps with all the existing map data, even though there is an overlapping area with the map data already secured. Since the map data is newly received and imaged, there is a problem in that the capacity of the processed data becomes large and the network and system are unnecessarily burdened.

In order to solve the above problem and provide improved geographic information, a method of minimizing retransmission of map data using a cache or prefetch technique has been proposed.

The cache is a technique of reusing information that has already been transmitted until the information is determined to be effective in order to reduce bandwidth consumption due to repetitive transmission of the same map data, and the prefetch data is overlapped between consecutively transmitted map data. If present, predictable map data can be predicted in advance due to the correlation between map data.

Among them, the cache technology may be classified into a method of using coordinates and a level (scale) and a method of caching by dividing the entire map into a grid.

First, the method using the coordinates and the level is less caching efficiency because the map data can be reused when the region to be provided is the region where the coordinates exactly match the cached region.

On the other hand, the method of caching by dividing into a grid is a method of dividing the national map into a certain size in a grid form to give an index for each grid, and cache the map data for each index using this grid. In this method, since the size of the map area provided by the level varies a lot, grid index management is inefficient at the upper level and cached map area is inefficient at the lower level. For example, when providing map information based on a certain size of grid, index management is not possible because the higher the level, the more the range and the number of indexes to be represented on the map increase. In addition, if the map information is provided at a lower level, the area of the map displayed is a very small range, but the area included in one grid is rather wide, so unnecessary clipping and additional drawing occur, thereby improving system operating performance. Lowers.

In other words, the above-described grid usage method uses a grid that is too small, and the efficiency of using the grid index at the top level is low, and when the grid is too large, the size of the unit grid to be drawn increases, so that the lower level does not need to draw a large range. Drawing performance is degraded.

The present invention has been made to solve the problems of the prior art as described above, and an object of the present invention is to provide a map providing method and a map service providing system that can more efficiently manage grid index and cached map data. have.

In order to achieve the above object and to solve the above problems of the prior art, the present invention provides a map providing method for providing map information for each index of the grid by dividing the entire map into a grid (grid) form A first step of receiving a scale level of a search target requested by a user; A second step of varying a grid size of a map according to the received scale level; And a third step of providing map data of a corresponding search target for each variable grid size.

In addition, the present invention provides a map service providing system for dividing an entire map into a grid to provide map information for each index of the grid, wherein the map grid is arranged according to a scale level of a search target requested by a user. A web server of varying sizes and providing map data of a corresponding search target for each of the variable grids, and a cache or prefetch for receiving the map data provided from the web server and receiving the map data for each grid; A map service providing system including a user terminal performing a prefetch) function is provided.

According to the present invention, an optimal grid size can be provided according to a scale level of a search target requested by a user, and a grid for each scale level can be managed by constructing an area quadrant tree. In the grid configuration for the entire map, cache and prefetch for map data is performed using virtual meshes having different sizes according to scale levels.

Hereinafter, with reference to the accompanying drawings will be described a map providing method and a map service providing system according to the present invention.

First, the overall configuration and operation of the map service providing system according to the present invention will be described.

1 is a diagram showing the overall configuration of a map service providing system according to the present invention.

As shown in the drawing, the map service providing system according to the present invention divides the entire map into a grid, and provides a web server 100 to provide map information for each index of the grid, and the web server 100. It includes a user terminal 200 for displaying the map information for each grid provided by the).

Here, the web server 100 is configured to manage the various map data by the database through the map database 110, and retrieves and provides the corresponding map data from the map database 110 at the request of the user terminal 200. It is a server device.

The web server 100 provides a web page for a map service through the Internet. When the user terminal 200 connected through the Internet requests a search target, the map generator 130 corresponds to the search target. After generating map data for displaying map information, the map data is loaded through a web browser of the user terminal 200.

At this time, the map generation unit 130 varies the grid size of the map according to the scale level of the search target and provides map data of the search target for each of the variable grids.

The user terminal 200 includes a map display control unit 210, a user interface 230, a communication unit 250, a memory 270, and a display unit 290.

The user terminal 200 is a system for providing map information to a user. After the map data is acquired from the web server 100 under the control of the map display control unit 210, the user terminal 200 converts the data to the display unit 290. ) To provide a map-like image.

The user interface 230 is a graphical user interface, which shows a map image to the user and searches for a map from the user (eg, a telephone number, a trade name, a place name, a branch number, etc.), and a map of the map. Map change requirements such as zooming in, zooming out, and panning (hereinafter referred to as 'scale level') are input.

The communication unit 250 requests map data according to a user's search target or scale level through a standard interface of the web server 100 and receives map data according to the request.

The display unit 290 displays a map image corresponding to the map data received through the communication unit 250 to show a map according to a user's request.

The memory 270 constitutes a memory for performing a cache or prefetch function for the map data provided by the web server 100, and uses the map data stored in the memory 270. Therefore, it can be reused as data due to redundancy and association between the map data provided by the web server 100.

In the map service providing system of the present invention configured as described above, a map information providing method according to a scale level will be described.

First, the user terminal 200 accesses a web server 100 that provides a map service through the Internet, and then requests map information through a web page provided by the web server 100. That is, the search object and the scale level of the search object are requested through the web page.

The process of changing the grid size of the map in the web server 100 according to the scale level of the search target requested by the user will be described in detail.

2 is a diagram illustrating the entire process of the map providing method of the web server provided by the present invention.

As shown, the web server 100 receives the search target and the scale level of the search target requested by the user from the user terminal 200 in the process (S211).

The web server 100 manages the grid for each level by applying different grid configuration methods according to the scale level of the search target requested by the user. To this end, it is preferable to preset a reference level for selectively applying a grid configuration method according to the scale level.

Hereinafter, it is assumed that the scale level of the map information that can be provided to the user exists from one level (hereinafter referred to as 'maximum reduction level') to 12 levels (hereinafter referred to as 'maximum enlargement level').

For example, the reference level is set to seven levels. In addition, an optimal grid is defined for the set reference level, and a grid for the reference level is referred to as a 'reference grid' and a mesh of the reference grid is referred to as a 'mesh'. 3 shows an example of a reference grid configuration for seven levels set as reference levels.

After recognizing the scale level of the search target received in the step S211, it is determined whether the scale level of the search target is equal to or less than the reference level (S212).

If the scale level is less than or equal to the reference level, that is, within 7 levels of the maximum reduction level, the base mesh is bundled by 4 ⁿ to generate a virtual mesh (S213). At this time, n = 1 for 6 levels, n = 2 for 5 levels,... , N = 6 for 1 level.

FIG. 4 illustrates each grid configuration according to virtual meshes corresponding to 6, 5, and 4 levels based on the reference level (7 levels) of FIG. 3. In other words, the base mesh is grouped by 4 ⁿ according to the scale level (n) based on the reference level to create a virtual mesh.

On the other hand, if the scale level is within the maximum magnification level from 8 levels, the base mesh is divided by 4 ⁿ to generate a virtual mesh (S214). At this time, n = 1 for 8 levels, n = 2 for 9 levels,... , N = 5 for 12 levels.

FIG. 5 illustrates a configuration of an area quadrant tree corresponding to levels 8 and 9 based on the reference level (level 7) of FIG. 3. As shown, a virtual mesh according to the scale level is created by dividing one mesh into four meshes (North East (NE) / Northwest (NW) / Southeast (SE) / Southwest (SW)).

As shown in FIG. 6, for a scale level of 8 or more levels, the base mesh is divided by 4 ⁿ according to the scale level n to form a virtual mesh having a region quadrant tree having n depth.

As described above, a virtual mesh for each scale level is generated to configure an optimal grid according to the scale level.

Subsequently, the grid index for the entire map is reconstructed based on the generated virtual mesh (S215), and the grid-specific map data corresponding to the search target requested by the user is provided (S216).

Therefore, at the scale level of 7 or less of the reference level, a grid index suitable for each scale level is used, and at scale levels exceeding 7 levels, the grid for each level is used by using an area quadrant tree having different depths according to each scale level. Manage.

According to the map providing method of the present invention, the user terminal 200 receives map data for each grid according to the grid index corresponding to the scale level of the search target requested by the user.

The user terminal 200 caches and prefetches map data for each grid using a virtual mesh having a different size according to the requested scale level.

The above-described map providing method and map service providing system of the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded on a computer readable medium. The computer readable medium may include a program command, a data file, a data structure, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

The map providing method and the map service providing system of the present invention have the following effects.

First, according to the present invention, the grid index can be managed more efficiently by creating an optimal grid size according to the scale level of the map requested by the user and managing the grid for each level.

Second, according to the present invention, by minimizing retransmission of data using an optimal cache and prefetch method, it is possible to shorten the reloading time of map data and improve the viewing speed of the map image.

Claims (11)

In the map providing method for dividing the entire map into a grid (grid) to provide the map information by index of each grid, A first step of receiving a scale level of a search target requested by a user; A second step of varying a grid size of a map according to the received scale level; And A third step of providing map data of a corresponding search target for each variable grid size; Map providing method comprising a. The method of claim 1, The first step, Providing a web page for providing map information when the user terminal accesses a web server providing map information; Receiving a scale level of a search target or a search target input by a user through the provided web page; Map providing method comprising a. The method of claim 1, The second step, And determining a grid size based on a virtual mesh having different sizes according to the scale level. The method of claim 1, The second step is Setting a reference level at a scale level available to the user; Setting a reference grid for the set reference level and setting a mesh of the reference grid as a base mesh; Reconstructing the base mesh according to the scale level to reconstruct a grid index Map providing method comprising a. The method of claim 4, wherein The step of configuring the grid index, If the scale level falls within the maximum reduction level from the reference level, generating a virtual mesh by combining the base meshes by 4 ⁿ and constructing a grid index based on the generated virtual mesh; If the scale level falls within the maximum magnification level from the level exceeding the reference level, the base mesh is divided by 4 ⁿ to generate a virtual mesh having an area quadrant tree having a depth of n, and the generated virtual mesh. Steps to Configure a Grid Index with Units Map providing method comprising a. The method of claim 5, The third step, And generating map data for each grid based on the virtual mesh to provide map data of a corresponding search target. The method of claim 6, Map data for each grid that provides the virtual mesh as a unit is provided to a user terminal. The user terminal, And receiving map data for each grid corresponding to the scale level to perform a cache or prefetch function for the map data. A computer-readable recording medium in which a program for executing the method of any one of claims 1 to 7 is recorded. In the map service providing system for dividing the entire map into a grid (grid) to provide map information for each grid index (index), A web server for varying a grid size of a map according to a scale level of a search target requested by a user and providing map data of a corresponding search target for each of the variable grids; A user terminal that receives map data provided by the web server and performs a cache or prefetch function on the received grid data for each grid. Map service providing system comprising a. The method of claim 9, The web server, A map database that stores map data for the entire map, A map generation unit for varying the grid size of the map according to the scale level of the search target and generating map data for each variable grid by searching map data for the corresponding search target in the map database. Map service providing system comprising a. The method of claim 9, The user terminal, Map display control unit for controlling the overall terminal system, A user interface for receiving a search target or a scale level of the search target from a user, A communication unit for requesting map data for the search target and receiving map data corresponding to the search target; A memory for storing the map data for each grid to perform a cache or prefetch function on the received grid data for each grid; Display unit for displaying the received map data Map service providing system comprising a.

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