WO2009082073A1

WO2009082073A1 - Method for displaying three dimensional map data and apparatus for executing the method

Info

Publication number: WO2009082073A1
Application number: PCT/KR2008/003803
Authority: WO
Inventors: Yun Han Kim
Original assignee: Thinkware Systems Corporation
Priority date: 2007-12-21
Filing date: 2008-06-30
Publication date: 2009-07-02
Also published as: KR20090067536A; KR100933879B1

Abstract

A method and an apparatus for displaying 3D map data are provided. The method includes: defining a size of a drawing dot for each screen height; and providing a 3D map image through leveling with respect to linear map data at a predetermined point by using the drawing dot for each screen height.

Description

METHOD FOR DISPLAYING THREE DIMENSIONAL MAP DATA AND APPARATUS FOR EXECUTING THE METHOD

Technical Field The present invention relates to a method for displaying map data for a three dimensional (3D) map service geographic information system, and more particularly, to a method for displaying 3D map data which can provide a 3D map service using perspective of linear data and an apparatus using the method.

Background Art

A geographic information system (hereinafter, referred to as "GIS") refers to an information system which integrates attribute data related to geographic data.

Through the GIS, location information such as longitude, latitude, and address of a location using the GIS can be conveniently retrieved, and the GIS provides the user with required geographic and map information in an appropriate map type image through query and analysis on spatial data stored in a relational database.

Currently, map services based on the GIS such as a navigation system and the like, are provided to terminals of mobile environments.

The navigation system receives predetermined data from a global positioning system (GPS) satellite orbiting over the Earth by being equipped with a GPS module, and calculates a location of a moving body based on the received data. The navigation system may provide a map image which is map-matched with map data stored in advance as well as a map image of a required location.

FIG. 1 illustrates an exemplary embodiment of linear road data. As illustrated in FIG. 1 , generic road data 101 used for a map service in the GIS or in a navigation system includes linear type data (Hereinafter, referred to as "linear data") having multiple interpolations.

Generally, to use the linear data as display data which is to be applied to a map image, leveling, which makes the linear data into a plane by considering a width of a road, is required.

FIG. 2 illustrates leveling operations with respect to linear road data 201.

The linear road data 201 is generated to be polygon data 202 in a polygon shape by considering a predetermined width A, thereby being used to be display data that can be displayed in a map image. In detail, the plane road data 202 may be generated through the leveling operation in which the predetermined width A is applied on the linear road data 201. After the leveling operation is performed, a quality of the map image is improved, however an amount of data for the map service is increased. In particular, in the case of a vast area including a large amount of map data, an amount of data may be significantly increased when using polygon data in which leveling operation is performed. To minimize such problems, a method for displaying a map image using linear data is provided. A conventional map service map employs a display scheme using a predetermined size of a drawing dot (Hereinafter, referred to as "polygon pen") to implement a visual effect which enables linear data to be viewed as plane data.

That is, when the linear data is drawn using the polygon pen on a screen, the linear data may be displayed as plane data with a predetermined width corresponding to a pixel size of the polygon pen.

The polygon pen may consist of various sizes of pixels as illustrated in FIG. 3, and a pixel size of the polygon pen may be changed according to a level of the map image. As an example, when levels provided in the map service are provided 11 levels, a pixel size with respect to each level may differ from a 1 pixel to 11 pixels.

FIG. 4 illustrates a map image provided in a conventional map service according to an exemplary embodiment of a two dimensional (2D) map image using linear road map data.

According to levels of a map image, pixel sizes corresponding to the levels of the map image are selected, and linear data is drawn on a screen using a polygon pen of a selected pixel size. When the linear data is drawn using the polygon pen having the selected pixel size, as illustrated in FIG. 4, plane data 401 having a width corresponding to the pixel size may be displayed.

However, when a 3D map service is required to be provided, a 3D perspective with respect to the map data may not be represented using the conventional drawing method.

When converting a 2D polygon into a 3D polygon, perspective of 3D map service may be represented, however, an amount of data for the 3D map service may be increased.

Disclosure of Invention Technical Goals

The present invention provides a method and an apparatus for displaying 3D map data which can represent a 3D perspective using linear map data.

The present invention also provides a method and an apparatus for displaying 3D map data which can represent a map image with a 3D perspective as well as minimizing a data capacity.

Technical solutions

According to an aspect of the present invention, there is provided a method for displaying 3D map data including: defining a size of a drawing dot for each screen height; and providing a 3D map image through leveling with respect to linear map data at a predetermined point by using the drawing dot for each screen height.

The defining of the size of the drawing dot for each screen height may divide a display area on a screen based on y axis coordinates, and establish a size of the drawing dot being larger as the y axis coordinates values on a display area are smaller, and a size of the drawing dot being smaller as the y axis coordinates values on a display area are larger.

The providing of the 3D map image through leveling with respect to linear map data at the predetermined point by using the drawing dot for each screen height may include: reading linear map data at a corresponding point; dividing the linear map data according to the screen height having defined the drawing dot; and drawing the linear map data using a drawing dot having a size which corresponds to a screen height of each of the divided linear map data.

The drawing of the linear map data may include: drawing the linear map data using the drawing dot of the maximum size when linear map data corresponds to the minimum display area; drawing the linear map data using the drawing dot of the minimum size when linear map data corresponds to the maximum display area; determining a size of a drawing dot via linear interpolation between the drawing dot of the maximum size and of the minimum size, and drawing the linear map data using the determined drawing dot, when linear map data corresponds to remaining areas of the maximum and minimum display area.

According to another aspect of the present invention, there is provided an apparatus for providing a 3D map image including: a database storing linear map data and a size of a drawing dot which is determined in advance according to a screen height; and a map display unit displaying a 3D map image through leveling with respect to linear map data at a predetermined point by using a drawing dot for each screen height.

The map display unit may include: a search unit extracting linear map data at a corresponding point from the database; a display unit displaying the extracted linear map data; and a map execution module dividing the linear map data according to the screen height having defined the drawing dot, and drawing the linear map data using a drawing dot having a size which corresponds to the screen height of each of the divided linear map data.

Advantageous Effects

According to the present invention, it is possible to provide a map image with improved display by providing a display algorithm for a 3D map service through expressing perspective linear map data. According to the present invention, it is possible to minimize an amount of data and to improve a speed for display by providing a 3D map image using linear map data.

Brief Description of Drawings

FIG. 1 illustrates an exemplary embodiment of map data consisting of linear road data;

FIG. 2 illustrates leveling operations with respect to linear road data 201 ;

FIG. 3 illustrates an exemplary embodiment of a drawing dot used for leveling linear map data in a conventional display scheme;

FIG. 4 illustrates an exemplary embodiment of a two dimensional (2D) map image which is displayed by leveling the linear map data of FIG. 1 ;

FIG. 5 illustrates all operations of a method for displaying 3D map data according to an exemplary embodiment of the present invention; FIG. 6 illustrates a rectangular polygon for a 2D map image and a non- rectangular polygon for a 3D map image;

FIG. 7 illustrates an exemplary embodiment of a type of a drawing dot having different sizes according to a screen height; FIG. 8 illustrates operations of a method for displaying a 3D map image using linear map data;

FIG. 9 illustrates a 3D map image using linear map data according to a display scheme of the present invention; and

FIG. 10 illustrates an internal configuration of an apparatus for displaying 3D map data according to an exemplary embodiment of the present invention.

Best Mode for Carrying Out the Invention

Hereinafter, a method for displaying 3D map data according to an exemplary embodiment of the present invention will be described in detail by referring to accompanied drawings according to exemplary embodiments of the present invention.

The present invention relates to a display scheme which is to be applied to a 3D map service, and may display a 3D map image in which leveling is performed using linear map data.

In this specification, 'drawing dot' refers to a tool used for displaying linear map data on a screen, and more particularly, refers to a tool for easily drawing lines.

FIG. 5 illustrates all operations of a method for displaying 3D map data according to an exemplary embodiment of the present invention.

In operation S501 , a size of a drawing dot is defined for each screen height. The screen represents a display area which displays a 3D map image, and a circle- shaped or an oval shaped dot may be used for the drawing dot. In particular, the drawing dot may use an oval-shaped dot in which an x axis is longer than a y axis.

The operation of defining the drawing dot of operation S501 will be described in detail with reference to FIGS. 6 and 7.

In operation S502, when there is a request for a map image at a predetermined point from a user, linear map data at the predetermined point performs leveling using the drawing dot for each screen height, and 3D map image is provided. The 3D map image may represent 3D perspective since the linear map data is drawn using drawing dots having different sizes according to screen heights.

The operation of displaying the 3D map image using the linear map data will be described in detail with reference to FIG. 8.

FIG. 6 illustrates a rectangular polygon for a 2D map image and a non- rectangular polygon for a 3D map image.

As illustrated in FIG. 6, the 2D map image uses a rectangular-shaped polygon data, and a map image required for the 3D map service uses a non-rectangular -shaped polygon data. In detail, the 3D map service may be provided by converting the 2D polygon data into the 3D polygon data in the non-rectangular shape. To represent 3D perspective, the non-rectangular area of the 3D polygon becomes smaller as a height of a screen is greater based on y axis coordinates.

However, the method for displaying 3D map data according to the present invention may represent perspective of the 3D map image and reduce an amount of data by using linear map data instead of using the polygon map data in which leveling is performed. Drawing dots having different sizes may be defined in advance according to screen heights using perspective of the 3D map service.

FIG. 7 illustrates an exemplary embodiment of a type of a drawing dot having different sizes according to a screen height.

First, a display area 701 on a screen is divided based on y axis coordinates, and drawing dots having different sizes are established with respect to each of the divided display areas 701, the drawing dots having different sizes varying according to y axis coordinates values.

In this instance, a size of the drawing dot is established to be larger as the y axis coordinates values on a display area are smaller, that is as the display area is closer to a user's viewpoint, and a size of the drawing dot is established smaller as the y axis coordinates values on a display area are larger, that is as a display area is farther from the user's viewpoint.

As illustrated in FIG. 7, when the display area 701 is divided into at least two, a drawing dot 702 of a maximum size is established with respect to a minimum display area and a drawing dot 703 of a minimum size is established with respect to a maximum display area, the minimum display area including a minimum y axis coordinates value and the maximum display area including a maximum y axis coordinate value. Further to this, with respect to remaining display areas between the minimum and maximum display area, a size of a drawing dot 704 on a corresponding area may be established via linear interpolation which uses the drawing dots 702 and 703 of the maximum and minimum size. Consequently, sizes of drawing dots for representing 3D perspective may be established to be gradually smaller according to screen heights (y axis coordinates values) of the display area 701. The sizes of the drawing dots according to each of the screen heights may be defined according to map levels provided in the 3D map service.

FIG. 8 illustrates operations of a method for displaying a 3D map image using linear map data.

In operation S801, linear map data at a corresponding point is read to provide a 3D map service requested by a user.

In operation S802, the linear map data is divided according to the screen height having defined the drawing dot. In detail, the linear map data is divided based on an identical criterion, the linear map data having been read in order to use a drawing dot with a corresponding size for each area is divided based on the identical criterion.

In operation S803, linear map data is drawn on a screen using a drawing dot with a size corresponding to the screen height of each of the divided linear map data. In the case of linear map data which is to be displayed on a minimum display area having a lowest height, linear map data of a corresponding area is drawn using a drawing dot having a maximum size, and in the case of linear map data which is to be displayed on a maximum display area having a highest height, linear data of a corresponding area is drawn using a drawing dot having a minimum size. In the case of linear map data which is to be displayed on an area between the minimum display and the maximum display area, a size of a drawing dot is determined via linear interpolation between the maximum size of the drawing dot and the minimum size of the drawing dot and linear map data of a corresponding area may be drawn using the determined drawing dot.

As illustrated in FIG. 9, by drawing the linear map data using drawing dots having different sizes according to a screen height, the linear map data may be displayed to be plane map data 901 having a width corresponding to a size of a drawing dot. The plane map data 901 uses a larger-sized drawing dot in the case of a display area which is closer to a user's viewpoint and uses a smaller-sized drawing dot in the case of a display area which is farther from the user's viewpoint, thereby representing perspective of the plane map data 901, that is a width of the plane map data 901 becomes smaller. As described above, the method for displaying 3D map data according to the present invention may represent a 3D perspective by drawing linear map data on a screen using drawing dots having different sizes according to a screen height.

Hereinafter, an apparatus for displaying 3D map data which implements the method for displaying 3D map data will be described. FIG. 10 illustrates an internal configuration of an apparatus for displaying 3D map data according to an exemplary embodiment of the present invention.

The apparatus for displaying 3D map data according to the present invention includes a personal computer (PC), a navigation system, a mobile phone, a personal digital assistant (PDA), a smart phone, and the like which can provide a map service based on GIS.

As illustrated in FIG. 10, the apparatus for displaying 3D map data may include a map database 110 and a map display unit in order to provide a 3D map image when a user requests a map at a required area.

The map database 110 may store map data regarding an entire country, and, in particular, store road data in linear map data. To provide a map image using the linear map data, the map database 110 may store a size of a drawing dot which is determined in advance according to each screen height.

With respect to the drawing dot for each screen height, after dividing a display area on a screen based on a y axis coordinates, a drawing dot of a maximum size on a minimum display area which includes a minimum y axis coordinates value is established and a drawing dot of a minimum size on a maximum display area which includes a maximum y axis coordinate value is established. The drawing dot may use a circle-shaped or an oval-shaped dot, and, in particular may use an oval-shaped dot with a longer x axis than a y axis. The map display unit provides a 3D map image through leveling with respect to linear map data at a predetermined point requested by a user by using the drawing dot for each screen height. The map display unit may include a search unit 120, a storage unit 130, a map execution module 140, and a display unit 150.

The search unit 120 searches for the linear map data at the point requested by the user in the map database 110, and the storage unit 130 temporarily stores the retrieved linear map data. The map execution module 140 performs all operations of displaying the linear map data of a 3D map image on the display unit 150 by using a drawing dot for each screen height. The map execution module 140 divides the linear map data according to the screen height having defined the drawing dot, and draws the linear map data using a drawing dot having a size which corresponds to the screen height of each of the divided linear map data.

The map execution module 140 draws the linear map data using a drawing dot of a maximum size when linear map data corresponds to a minimum display area, and draws the linear map data using a drawing dot of a minimum size when linear map data corresponds to a maximum display area. When linear map data corresponds to an area between the minimum and maximum display areas, the map execution module 140 determines a size of a drawing dot via linear interpolation which uses the maximum size and the minimum size of the drawing dot, and draws the linear map data at a predetermined point using the determined drawing dot.

That is, the map execution module 140 may represent 3D perspective according to a user's viewpoint by using a drawing dot for each screen height when drawing the linear map data on the display unit 150.

Therefore, the present invention may provide a 3D map service using linear map data by drawing the linear map data using a drawing dot having different sizes for each screen height. The method for displaying 3D map data according to the above-described exemplary embodiments may be recorded in computer-readable media including program instructions to implement various operations embodied by a computer. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks and DVD; magneto-optical media such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. The media may also be a transmission medium such as optical or metallic lines, wave guides, and the like, including a carrier wave transmitting signals specifying the program instructions, data structures, and the like. Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described embodiments of the present invention. The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching.

Therefore, it is intended that the scope of the invention be defined by the claims appended thereto and their equivalents.

Claims

1. A method for displaying three dimensional (3D) map data, the method comprising: defining a size of a drawing dot for each screen height; and providing a 3D map image through leveling with respect to linear map data at a predetermined point by using the drawing dot for each screen height.

2. The method of claim 1, wherein the defining of the size of the drawing dot for each screen height comprises: dividing a display area on a screen based on y axis coordinates; and establishing drawing dots having different sizes with respect to each of the divided display areas.

3. The method of claim 2, wherein the defining of the size of the drawing dot for each screen height establishes a size of the drawing dot being larger as the y axis coordinates values on a display area are smaller, and a size of the drawing dot being smaller as the y axis coordinates values on a display area are larger.

4. The method of claim 2, wherein the defining of the size of the drawing dot for each screen height establishes a drawing dot of a maximum size on a minimum display area and a drawing dot of a minimum size on a maximum display area, the minimum display area including a minimum y axis coordinates value and the maximum display area including a maximum y axis coordinate value.

5. The method of claim 4, wherein the defining of the size of the drawing dot for each screen height establishes, with respect to remaining display areas between the minimum and maximum display area, a size of a drawing dot via linear interpolation which uses the drawing dots of the maximum and minimum size.

6. The method of claim 2, wherein the drawing dot is a circle-shaped or an oval- shaped dot.

7. The method of claim 4, wherein the providing of the 3D map image through leveling with respect to linear map data at the predetermined point by using the drawing dot for each screen height comprises: reading linear map data at a corresponding point; dividing the linear map data according to the screen height having defined the drawing dot; and drawing the linear map data using a drawing dot having a size which corresponds to a screen height of each of the divided linear map data.

8. The method of claim 7, wherein the drawing of the linear map data comprises: drawing the linear map data using the drawing dot of the maximum size when linear map data corresponds to the minimum display area; and drawing the linear map data using the drawing dot of the minimum size when linear map data corresponds to the maximum display area.

9. The method of claim 8, wherein the drawing of the linear map data determines a size of a drawing dot via linear interpolation between the drawing dot of the maximum size and of the minimum size, and draws the linear map data using the determined drawing dot, when linear map data corresponds to remaining areas of the maximum and minimum display area.

10. At least one computer-readable storage medium storing instructions for implementing the method of any one of claims 1 through 9.

11. An apparatus for providing a 3D map image, the apparatus comprising: a database storing linear map data and a size of a drawing dot which is determined in advance according to a screen height; and a map display unit displaying a 3D map image through leveling with respect to linear map data at a predetermined point by using a drawing dot for each screen height.

12. The apparatus of claim 11 , wherein the drawing dot drawing dot which is determined in advance according to the screen height, divides a display area on a screen based on y axis coordinates, and establishes a drawing dot of a maximum size on a minimum display area which includes a minimum y axis coordinates value, and a drawing dot of a minimum size on a maximum display area which includes a maximum y axis coordinates value.

13. The apparatus of claim 12, wherein the drawing dot for each screen height is a circle-shaped or an oval-shaped dot.

14. The apparatus of claim 12, wherein map display unit comprises: a search unit extracting linear map data at a corresponding point from the database; a display unit displaying the extracted linear map data; and a map execution module dividing the linear map data according to the screen height having defined the drawing dot, and drawing the linear map data using a drawing dot having a size which corresponds to the screen height of each of the divided linear map data.

15. The apparatus of claim 14, wherein the map execution module draws the linear map data using the drawing dot of the maximum size when linear map data corresponds to the minimum display area, and draws the linear map data using the drawing dot of the minimum size when linear map data corresponds to the maximum display area.

16. The apparatus of claim 15, wherein the map execution module determines a size of a drawing dot via linear interpolation between the drawing dot of the maximum size and of the minimum size, and draws the linear map data using the determined drawing dot, when linear map data corresponds to remaining areas of the maximum and minimum display area.