JP2003330968A - Map display device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem of a map display device wherein the use of latitude/longitude information as index information quickly provides space information in a display region without analyzing a hierarchical structure of space information in a space data file of XML form, however, the addition of the latitude longitude information to the space information of the space data file enlarges the data size of the space data file. <P>SOLUTION: Planimetric feature information in the display region is retrieved from the XML map DF by referring to the information retrieval data where the planimetric feature information described in the XML map DF is managed in a multidimensional data structure. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to XML (eXt).
The present invention relates to a map display device and a map display program for displaying a map in accordance with feature information described in a map data file in an Ensible Markup Language format.

[0002]

2. Description of the Related Art G-X is a format for describing spatial information such as feature information indicating the position of a feature in a hierarchical structure.
ML and POIX (Point Of Interset)
eXchange Language) and the like have been proposed. These data formats are markup languages in the XML format, and describe spatial information in a hierarchical structure using tags. Tags and hierarchical structures are specified for each format.

When extracting desired spatial information from an XML format spatial data file, it is necessary to analyze the tree structure of the spatial information stored in the spatial data file. The processing amount of is increased. For example, in the case of an application that displays a map of the current position, it takes a long processing time to acquire the feature information about the feature existing in the display area from the XML tree structure. That is, unless the tree structure is analyzed and all the feature information in the spatial data file is referenced, the feature information regarding the features existing in the display area cannot be acquired, and the map is displayed. Will take longer. In particular, a microcomputer installed in a PDA such as a mobile information terminal or a mobile phone is a CPU or a ROM / RA.
Since the capacity of M is limited and its processing capacity is not higher than that of a general personal computer, the time until the map is displayed becomes extremely long.

Therefore, a technique for quickly knowing the spatial information without analyzing the hierarchical structure of the spatial information in the XML format spatial data file has been developed, and a map display device using the technique is disclosed in Japanese Patent Laid-Open No. 2001-175662. It is disclosed in the official gazette. That is, Japanese Patent Laid-Open No. 2001-175662
The publication discloses a technique in which latitude and longitude information is added to the spatial information of a spatial data file and the latitude and longitude information is used as index information.

[0005]

Since the conventional map display device is configured as described above, if the latitude / longitude information is used as index information, the hierarchical structure of the spatial information in the XML spatial data file can be analyzed. Without doing so, the spatial information in the display area can be quickly acquired. However, since the latitude and longitude information is added to the spatial information of the spatial data file, there is a problem that the data size of the spatial data file becomes large. In addition, since the tag of the index for search has a unique format, there is a problem that it cannot be applied to a format other than the format in which the unique extension of the tag is allowed.

The present invention has been made to solve the above problems, and a map display device and a map capable of displaying a map in a display area quickly without adding latitude / longitude information as index information. The purpose is to obtain a display program.

[0007]

A map display device according to the present invention refers to information search data that manages feature information described in an XML format map data file in a multidimensional data structure. A search means for searching the map data file for feature information in the display area is provided.

The map display device according to the present invention is provided with the data construction means for constructing the information retrieval data having the multidimensional data structure by inputting the feature information described in the map data file into the kd tree. It is a thing.

The map display device according to the present invention is provided with data construction means for constructing information retrieval data having a multidimensional data structure by inputting feature information described in a map data file into an MD tree. is there.

The map display device according to the present invention refers to an XML-format index file in which index information indicating a description position of feature information in a map data file is described to refer to information search data having a multidimensional data structure. The data construction means for constructing is.

The map display device according to the present invention is provided with communication means for obtaining a map data file and an index file from the outside via a network.

In the map display device according to the present invention, when the feature information managed in the information search data is added with the information indicating the degree of importance, the feature information of which degree of importance is equal to or higher than the reference value is searched. It was done like this.

The map display device according to the present invention receives the latitude / longitude information of the current position and designates the display area of the map based on the latitude / longitude information.

The map display program according to the present invention is X
Retrieval procedure for retrieving the feature information in the display area from the map data file by referring to the information retrieval data that manages the feature information described in the ML format map data file with a multidimensional data structure. Is provided.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1 is a block diagram showing a map display device according to Embodiment 1 of the present invention, in which 1 is a GP.
S (Global Positioning System)
em) GP that receives the latitude and longitude information of the current position from the satellite
S receiver, 2 is a user interface (User Interface)
ace) section 2a to input a map display request, a display area designating section (display area designating means) 3 for designating a display area of the map according to the latitude / longitude information received by the GPS receiver 1 A communication unit (communication means) that receives a map data file (hereinafter referred to as an XML map DF) in which feature information is described in XML format from an external computer via a network.

Reference numeral 4 is an XML for generating an XML tree showing the data structure of the XML map DF received by the communication unit 3.
A map data processing unit 5 is an XML space index processing unit that inputs the feature information described in the XML map DF into a kd tree to construct information search data having a multidimensional data structure. The XML map data processing unit 4 and the XM
The L space index processing section 5 constitutes data construction means.

Reference numeral 6 refers to the information retrieval data of the multidimensional data structure constructed by the XML spatial index processing unit 5 to retrieve the feature information in the display area designated by the display area designating unit 2 from the XML map DF. A map data management unit (search unit) 7 to be searched is a display unit (display unit) that displays a map according to the feature information searched by the map data management unit 6. FIG. 2 is a flowchart showing the processing contents of the map display device according to Embodiment 1 of the present invention,
FIG. 3 is a flowchart showing the processing contents of the map data management unit 6.

Next, the operation will be described. First, when the user operates the UI unit 2a to input a map display request (step ST1), the display area designation unit 2 obtains the latitude / longitude information of the current position received by the GPS receiver 1 (step ST2). The map display area is designated according to the latitude / longitude information and the map display area size (the display area size is determined from the screen size of the display, the map scale, etc.) (step ST3).

When the display area designating section 2 designates the map display area when the information retrieval data having the multidimensional data structure is already constructed, the map data management section 6 designates the information retrieval data having the multidimensional data structure. Refer to the XML Map DF
Feature information in the display area is searched from (details will be described later), but if information search data having a multidimensional data structure has not been constructed yet, construction of information search data is requested (step ST4).

When the XML map data processing unit 4 receives a request for constructing information search data from the map data management unit 6,
The XML map DF received by the communication unit 3 is obtained, and an XML tree showing the data structure of the XML map DF is generated (step ST5). Here, FIG. 4 shows G-XML.
5 shows an example of an XML map DF created based on the rules of FIG. 5, FIG. 5 shows a display example according to the description content of the XML map DF of FIG. 4, and the XML map data processing unit 4 uses an XML parser to An XML tree as shown in 6 is generated. It should be noted that the XML map DF does not necessarily have to be received from an external computer via the network, and the CD-RO
You may make it read from storage media, such as M and DVD-ROM.

The XML spatial index processing unit 5 is
When the L map data processing unit 4 creates an XML tree, X
The feature information described in the ML map DF is input to the kd tree to construct information search data having a multidimensional data structure (step ST6). Where the multidimensional data structure is
This is a data structure that enables efficient retrieval of feature information that is spatial data, and generally k-d trees, MD trees, and the like are known.

For example, when a kd tree having a bucket size (maximum number of data managed by leaf nodes) of 2 is used, the local feature information described in the XML map DF of FIG. 4 is described in the order of description in the file. When the data is input to the k-d tree, data for information retrieval having a tree structure as shown in FIG. 7 is constructed. The information search data in FIG. 7 is composed of a plurality of intermediate nodes and leaf nodes, and the circumscribed rectangles in the intermediate nodes and leaf nodes are the area of the feature information held by the node (hereinafter, the holding area). It means). That is, the numerical value in (□, □, □, □) of the circumscribed rectangle represents the holding area. Further, in the figure, the holding area of the node located in the upper part completely includes the holding area of the node located in the lower part. Note that the “Feature” hanging on the leaf node is linked to the “Feature” of the XML tree in FIG. 6, and if you look at the “Feature” hanging on the leaf node, you can see the corresponding “Feature” of the XML tree. Can be found immediately.

When the information search data having the multidimensional data structure is constructed as described above, the map data management unit 6
The feature information in the display area is searched from the XML map DF with reference to the information search data (step ST7).
Specifically, the feature information in the display area is searched as follows.

First, the map data management unit 6 sets the map display area designated by the display area designation unit 2 to V (sx, s).
(y, ex, ey), the process target node N is set to the root node of the information search data (the uppermost node in FIG. 7) (steps ST11, ST12). However, sx
Is the X coordinate minimum value of the display area, sy is the Y coordinate minimum value, ex
Is the maximum X coordinate value, and ey is the maximum Y coordinate value.

Next, the map data management unit 6 determines whether the processing target node N is a leaf node (step S).
T13). At this stage, since the processing target node N is the root node and the intermediate node, the processing target node N
Is not a leaf node. Map data management unit 6
Determines that the processing target node N is not a leaf node, the holding area B (N) of the processing target node N and the display area V
It is determined whether or not is crossed (step ST1
4).

If the holding area B (N) of the circumscribed rectangle and the display area V do not intersect, the map data management unit 6 does not hold the feature information in the display area, Even if the target node is moved to the lower node, there is no possibility that the lower node holds the feature information in the display area, and the series of search processing is ended. On the other hand, if the holding area B (N) of the circumscribed rectangle and the display area V intersect, the processing target node is moved to the lower node (step ST15). That is, the lower left node and the lower right node of the processing target node are set as the processing target nodes, and the search process is continued.

The map data management unit 6 is a processing target node N.
If it is determined that the node is a leaf node, the feature information held by the processing target node is added to the search list L (step 16). Specifically, as described above, the “Feature” hanging in the leaf node and the “Feature” in the XML tree in FIG. 6 are linked, so the link of the feature information held by the target node is linked. With reference to the information, the description position of the feature information in the XML map DF is added to the search list L. The map data management unit 6
It is generally known that the calculation cost for retrieving the feature information in the display area is log (n) when the number of feature information is n, and all the feature information in the XML map DF is calculated. The feature information in the display area can be searched without analyzing. Therefore, it is possible to retrieve the feature information in the display area faster than in the conventional method.

When the map data management unit 6 executes the feature information search processing as described above, the display unit 7 refers to the description position of the feature information described in the search list L,
The feature information is acquired from the XML map DF and the map is displayed according to the feature information (step ST8).

As is clear from the above, the first embodiment
According to this, the feature information in the display area is searched from the XML map DF by referring to the information search data that manages the feature information described in the XML map DF with a multidimensional data structure. Since it is configured, it is possible to quickly display the map in the display area without adding the latitude and longitude information as index information.

The display area designating unit 2, the map data management unit 6, the display unit 7, etc., which are the components of the map display device, may be configured by using hardware, but the functions of these components are realized. It is also possible to prepare a program (map display program) in which the processing content to be performed is described and execute the map display program by a computer (not shown).

In the first embodiment, the XML space index processing unit 5 inputs the feature information described in the XML map DF into the kd tree to construct the information search data having the multidimensional data structure. However, the present invention is not limited to this. For example, the feature information described in the XML map DF may be input to the MD tree to construct the information search data having a multidimensional data structure. Good.

Embodiment 2. In the first embodiment, X
It is shown that the ML spatial index processing unit 5 inputs the feature information described in the XML map DF to the kd tree to construct the information search data of the multidimensional data structure, but it is shown in FIG. As described above, the communication unit 3 receives the XML format index file (hereinafter, referred to as an XML index F) for reproducing the information search data having the multidimensional data structure, and the XML space index processing unit 5 receives the XML file.
The information search data having the multidimensional data structure may be reproduced by referring to the index information described in the L index F (information indicating the description position of the feature information in the XML map DF). FIG. 9 is an explanatory diagram showing a description example of the XML index F, and FIG. 10 is an explanatory diagram showing contents of tags of the XML index F in FIG. Note that the XML index F does not necessarily have to be received from an external computer via a network, and may be a CD.
It may be read from a storage medium such as -ROM or DVD-ROM.

Embodiment 3. In the first embodiment described above, the k-d tree is used as the multidimensional data structure. However, for example, the entire area of the XML map DF is simply divided into fine mesh areas, and each mesh area is regarded as one node. A managed mesh division method may be used. Further, in the above-described first embodiment, the one in which the display area of the map is designated according to the latitude / longitude information of the current position received by the GPS receiver 1 has been described. The position information of the current position may be acquired and the display area of the map may be designated according to the position information. Alternatively, the user may operate the UI unit 2a to specify the display area of the map.

Fourth Embodiment In the above-described first to third embodiments, the map data management unit 6 searches for the feature information in the display area, but the feature information managed in the information search data includes information indicating the degree of importance. If the feature information is added, the feature information in the display area may be searched only for the feature information having the reference value or more. Note that the information indicating the importance of the feature information is, for example, information having a larger value as the feature is more important, and is used as attribute information of the feature information managed by the intermediate node of the information search data. It may be added. As a result, it is possible to retrieve only the feature information of high importance in the display area.

[0035]

As described above, according to the present invention, the XM
A search means for searching the feature information in the display area from the map data file by referring to the information search data that manages the feature information described in the L-format map data file with a multidimensional data structure. Since it is configured to be provided, there is an effect that the map in the display area can be quickly displayed without adding the latitude / longitude information as index information.

According to the present invention, the data construction means for constructing the information retrieval data having the multidimensional data structure by inputting the feature information described in the map data file into the kd tree is constructed. Therefore, there is an effect that information search data having a multidimensional data structure can be constructed without complicating the configuration.

According to the present invention, since the feature information described in the map data file is input to the MD tree, the data construction means for constructing the information retrieval data having the multidimensional data structure is provided. There is an effect that information search data having a multidimensional data structure can be constructed without inviting a complicated structure.

According to the present invention, the information retrieval data having the multidimensional data structure is constructed by referring to the XML format index file in which the index information indicating the description position of the feature information in the map data file is described. Since the data construction means is provided, there is an effect that information retrieval data having a multidimensional data structure can be constructed without complicating the construction.

According to the present invention, since the communication means for obtaining the map data file and the index file from the outside via the network is provided, it is possible to easily obtain the map data file and the index file. is there.

According to the present invention, when the feature information managed in the information search data is added with the information indicating the degree of importance, the feature information having the degree of importance of the reference value or more is searched. Therefore, there is an effect that only the feature information having high importance can be searched in the display area.

According to the present invention, since the latitude / longitude information of the current position is received and the display area of the map is designated based on the latitude / longitude information, the map around the current position can be displayed. effective.

According to the present invention, the information search data managing the feature information described in the XML format map data file with the multidimensional data structure is referred to, and the map data file is displayed in the display area. Since the search processing procedure for searching the feature information is provided, there is an effect that the map in the display area can be quickly displayed without adding the latitude and longitude information as index information.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a map display device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the processing contents of the map display device according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing the processing contents of a map data management unit.

FIG. 4 is an XM created based on the G-XML convention.
It is explanatory drawing which shows an example of L map DF.

5 is an explanatory diagram showing a display example according to the description content of the XML map DF of FIG.

FIG. 6 is an explanatory diagram showing an XML tree.

FIG. 7 is an explanatory diagram showing tree-structured information search data.

FIG. 8 is a configuration diagram showing a map display device according to a second embodiment of the present invention.

9 is an explanatory diagram showing a description example of an XML index F. FIG.

FIG. 10 is an explanatory diagram showing contents of tags of an XML index F in FIG.

[Explanation of symbols]

1 GPS receiver, 2 display area designating section (display area designating means), 2a UI section, 3 communication section (communication means), 4
XML map data processing unit (data construction means), 5 XML
L space index processing section (data construction means), 6 map data management section (search means), 7 display section (display means).

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01C 21/00 G01C 21/00 B G08G 1/137 G08G 1/137 G09B 29/00 G09B 29/00 AZ 29/10 29/10 A (72) Inventor Kazuo Seo 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. F-term (reference) 2C032 HB05 HB22 HB25 HC08 HC13 HC23 HC32 HD03 2F029 AB07 AC02 AC14 5B075 ND06 ND36 PP10 UU13 5H180 BB01 FF05 FF22 FF32

Claims (8)

[Claims] 1. A display area designating unit for designating a display area of a map and information search data for managing feature information described in an XML format map data file by a multidimensional data structure. A search means for searching the map data file for feature information in the display area designated by the display area designation means, and a display means for displaying a map in accordance with the feature information searched by the search means. Map display device. 2. The data constructing means for constructing information retrieval data having a multidimensional data structure by inputting feature information described in a map data file into a kd tree. 1. The map display device described in 1. 3. The data constructing means for constructing information retrieval data having a multidimensional data structure by inputting feature information described in a map data file into an MD tree. Map display device. 4. An XM in which index information indicating a description position of feature information in a map data file is described.
2. The map display device according to claim 1, further comprising data construction means for constructing information retrieval data having a multidimensional data structure by referring to the L-format index file. 5. The map display device according to claim 4, further comprising communication means for obtaining a map data file and an index file from the outside via a network. 6. The search means searches for feature information whose importance is equal to or higher than a reference value when the information indicating the importance is added to the feature information managed in the information search data. The map display device according to any one of claims 1 to 5. 7. The display area designating means receives the latitude and longitude information of the current position and designates the display area of the map based on the latitude and longitude information. The map display device according to any one of items. 8. A display area designation processing procedure for designating a display area of a map and information search data for managing feature information described in an XML format map data file in a multidimensional data structure are referred to. And a search processing procedure for searching the map data file for the feature information in the display area designated by the display area designation processing procedure, and a display for displaying the map according to the feature information retrieved by the search processing procedure. A map display program that causes a computer to execute the processing procedure.