JPH10177638A - Picture displaying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a stereoscopic map without any sense of incompatibility regardless of the presence of the height information of each map element. SOLUTION: The three-dimensional model of geography is prepared based on altitude data included in map information registered in a database (a step 400), and whether or not height information is included in the shape data of each map element of attribute information registered in the database is judged (a step 401). Then, when the height information is included in the shape data, the three-dimensional model of the map element is prepared by using the shape data (a step 403), and when the height information is not included in the shape data, the three-dimensional model of the map element is prepared by using the shape data and the height information calculated from the altitude data included in the map information registered in the database.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map information processing system and, more particularly, to a navigation device capable of displaying a three-dimensional map that does not give a driver a sense of discomfort.

[0002]

2. Description of the Related Art In a map information system used for urban development and land management, etc., map information (elevation data of terrain, etc.) and attribute information (each map element (building, road, etc.)) registered in a database are used. It is required to reproduce a three-dimensional image (hereinafter, referred to as a landscape image) in which a building or the like is matched with the background based on information including data including shape data and names, etc. Have been. Therefore, as a method for responding to such a demand, a landscape image synthesizing method described in Japanese Patent Application Laid-Open No. 62-274469 described below has been proposed.

A landscape image synthesis processing method described in Japanese Patent Application Laid-Open No. 62-274469 discloses a method of combining a three-dimensional image of terrain created based on map information and a three-dimensional image of each map element created based on attribute information. This is a method of creating a more natural landscape image by combining. According to this method, it is possible to more realistically display a scenery or the like viewed from near the ground, which is difficult to grasp at a glance of the map. That is,
If this method is applied to a navigation system, the driver can grasp the situation around the actual traveling position of the vehicle from the three-dimensional map displayed on the display or the like without feeling uncomfortable.

[0004]

By the way, Japanese Patent Application Laid-Open No. Sho 62
The landscape image synthesizing method described in Japanese Unexamined Patent Publication No. -274469 is based on the premise that height information on all map elements is registered in a database. Therefore, there is little possibility that the database of the existing map information system or the database of various map information systems provided in the future can be used as it is.

[0005] In the scenery image synthesizing method described in JP-A-62-274469, the database is not updated even if the traffic environment changes due to road maintenance or the like. Therefore, in the navigation system to which the present method is applied, map information at a certain point in the past is registered in the database unless the database is artificially updated periodically, so that it is suitable for the current traffic environment. 3D map is not displayed. In other words, regular maintenance of the database is required to provide the latest traffic information to the driver.

Accordingly, the present invention provides an image display device capable of displaying a three-dimensional map without a sense of incongruity regardless of the presence or absence of height information of each map element, and efficiently stores databases of various map information systems. The purpose is to use it. It is another object of the present invention to provide a navigation system using such an image display device capable of displaying the latest three-dimensional map suitable for the current traffic environment.

[0007]

In order to achieve the above object, an object of the present invention is to provide an image display device for displaying an image of a map represented by the map information based on the map information, wherein the three-dimensional shape of the ground surface is provided. Terrain data, three-dimensional data representing a three-dimensional shape including the height of a structure of a structure located on the ground surface, and plane data representing a two-dimensional shape of a structure different from the structure Terrain model generation means for generating a three-dimensional terrain model represented by the terrain data stored in the map information, and each plane data stored in the map information. Two-dimensional model generating means for respectively generating a model of each of the two-dimensional structures; and three-dimensional model generating each of the three-dimensional models of the three-dimensional structures represented by the three-dimensional data stored in the map information. A terrain model generated by the terrain model generating means, wherein the terrain model generating means generates a model of each structure generated by the two-dimensional model generating means and a model of each structure generated by the three-dimensional model generating means. Creating a projection map in which the combining means projects the terrain model on which the model of each of the structures is arranged onto a projection plane determined with respect to an arbitrary viewpoint position, as the image of the map to be displayed. An image display device comprising: a projection unit.

Therefore, according to the image display device of the present invention, even if the map information contains both shape data representing the two-dimensional shape of the structure and shape data representing the three-dimensional shape of the structure. That is, it is possible to display a three-dimensional map without a sense of incongruity regardless of the presence / absence of height information of each structure. Therefore, it seems that the databases of various map information systems can be used as they are. In addition, if such an image display device is mounted on a vehicle and the shape data of the terrain included in the map information is appropriately corrected in accordance with the gradient of the traveling path of the vehicle, the latest three-dimensional shape suitable for the current traffic environment can be obtained. Map display becomes possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a case where an embodiment according to the present invention is applied to a navigation device will be described with reference to the accompanying drawings.

First, the basic configuration of the navigation device according to the present embodiment will be described with reference to FIG.

The present navigation apparatus has a storage device 103 (CD-ROM, IC) storing a database in which map information (such as elevation data of terrain) and attribute information (such as shape data representing the shape of each map element) are registered. And a display 102 (CR) for graphically displaying a three-dimensional map or the like created from map information or the like stored in the storage device 103.
T, liquid crystal display, etc.), an audio input / output device 104 for inputting / outputting audio data, and an input device for receiving input from a driver (hard switches such as joysticks and scroll keys, a touch panel displayed on the display 102, etc.) 105, an arithmetic processing unit 101 for controlling the entire navigation apparatus, and a GPS from an artificial satellite.
A GPS receiving device 109 for receiving a signal, a receiving device 110 for receiving road traffic information (information on traffic regulation such as road closure by construction, information on a parking lot, etc.) and FM multiplex broadcasting transmitted from a beacon on the road, A LAN device 111 for controlling information transfer between the ECU mounted on the vehicle (transfer of information regarding the opening / closing state of doors, the lighting state of each light, the state of the engine, etc.), and an arithmetic processing unit 101
Sensors 106 and 10 for obtaining parameters used in the detection processing of the running position of the vehicle executed in
7, 108, and 112. The various sensors referred to here are sensors generally mounted on a normal vehicle.Specifically, the traveling direction of the vehicle based on a predetermined direction (for example, east) is determined using geomagnetism. Gyro 108 (optical gyro, optical gyro,
A wheel speed sensor 106 that measures the angle at which the vehicle bends based on the difference between the rotational speeds of the left and right wheels used for detecting the turning of the vehicle, a gradient sensor 112 that detects the gradient of the traveling path of the vehicle, and the like. Etc. correspond to this. The video signal S1 transmitted from the arithmetic processing unit 101 to the display 102 generally includes an NTSC signal (National Television System Committ) created by linearly converting an RGB signal.
ee) has been adopted.

The arithmetic processing unit 101 shown in FIG.
As shown in FIG.
203, a RAM 1204 storing programs and the like defining various arithmetic processes, and a CPU 12 executing various arithmetic processes and the like in accordance with the programs stored in the RAM 1204.
01 and DMA (Direct Memory Access) for realizing high-speed data transfer between each device and the RAM 1202
1202, a drawing controller 1205 for executing a conversion process from vector data to pixel data, a drawing process for a graphic element, and the like, and a VRAM 1206 storing the color of each pixel.
And the color of each pixel stored in the VRAM
A color pallet 1207 for converting the signal into a B signal and transferring the signal to the display 102;
A / D converter 1 for digitally converting an output signal or the like from the device 8
208 and an SC for converting a serial signal to a parallel signal.
An I1209, a PIO 1210 for applying a parallel signal to a bus connecting each device, and a counter 1211 for integrating a pulse signal are provided.

Further, the functional configuration of the arithmetic processing unit 101 will be described as follows. That is, as shown in FIG. 3, the arithmetic processing unit 101 in FIG.
A data reading unit 309 for extracting map information and the like from a database stored in a GPS, a command analysis unit 300 for analyzing commands and the like input by a driver, a GPS receiving device 10
A position calculating unit 301 for sequentially calculating the running position of the vehicle using the GPS signal S8 and the like received by the
6, a map match processing unit 303 for executing a map match process for correcting the traveling position of the vehicle calculated by the position calculation unit 301 using the output signal S5 from the gyro 108 and the output signal S7 from the gyro 108. And a trajectory storage unit 304 that stores the traveling position of the vehicle corrected at the appropriate timing and road data (set data of links connecting nodes) included in the map information extracted by the data reading unit 309 between two points. 305, a route storage unit 310 that stores the route information obtained by the search by the route calculation unit 305, and a map information that the data reading unit 309 retrieves. A display processing unit 302 that performs a stereoscopic map creation process by executing a stereoscopic map creation process to be described later using the A menu display unit 307 that displays a touch panel and the like, a route guidance unit 308 that searches for arbitrary route information from the route information stored in the route storage unit 310, and a database update process described below using the output of the gradient sensor 112. And a database updating unit (not shown) for performing the processing.

The description of the basic configuration of the navigation device according to the present embodiment is now completed, and the various processes executed by each block of the arithmetic processing unit 101 shown in FIG. 3 will be described in order. go.

First, an outline of a process for realizing a basic function as a normal navigation device will be described. However, here, it is assumed that an appropriate three-dimensional map created by the display processing unit 302 is already displayed on the display 102.

The position calculating section 301 normally calculates the running position (xg, yg, zg) of the vehicle sequentially using the GPS signals S8 from three or more artificial satellites received by the GPS receiving device 109. However, when approaching the inside of a tunnel or a building shadow where the GPS signal S8 cannot be received, the position calculating unit 301
Are output signal S5 from wheel speed sensor 106, output signal S7 from gyro 108, output signal S6 from direction sensor 107, and output signal S11 from gradient sensor 112.
And the following formula is used to sequentially calculate the traveling position (x, y, z) of the vehicle.

[0017]

(Equation 1)

[0018]

(Equation 2)

[0019]

(Equation 3)

Here, θ is the traveling direction of the vehicle detected by the gyro 108 and the direction sensor 107, and R is
The inclination angle of the vehicle detected by the inclination sensor 112, Δ
L ₁ is the travel distance of the vehicle calculated from the integral value of the wheel speed detected by the wheel speed sensor 106. Also, (x ₀ , y
₀ , z ₀ ) are the coordinates of the traveling position of the vehicle calculated last time.

Thereafter, the map match processing unit 303 calculates the traveling position (x, y,
In order to remove errors (errors caused by output errors of various sensors) included in z), a map matching process is executed.
That is, the road recognized from the road data included in the map information extracted by the data reading unit 309 and the position calculation unit 30
1 to recognize the traveling path of the vehicle by comparing it with the traveling position (x, y, z) of the vehicle, and furthermore, the position of the traveling path of the vehicle so that the traveling path and the traveling position of the vehicle can be matched. , The traveling position (x, y, z) of the vehicle is corrected.

In this way, finally the traveling position of the vehicle
When (x, y, z) is determined, the display processing unit 302 updates and displays an icon or the like at a position corresponding to the traveling position (x, y, z) of the vehicle on the three-dimensional map displayed on the display 102. I do. At this time, the gyro 108 and the direction sensor 10 are used so that the driver can easily confirm the course to the destination.
The traveling direction and the like of the vehicle detected at 7 are also displayed.

Further, when the driver instructs guidance to a desired destination with the input device, the route guidance unit 308 stores the route storage unit 3 in accordance with the analysis result of the command analysis unit 300.
From among the route information stored in 10, the route information indicating the optimal route to the destination desired by the driver is searched. The optimum route here is, for example, the shortest route in consideration of the cost and the required time, and in the present embodiment, the receiving device 11
The route determined based on the road traffic information and the like received at 0, the traveling position (x, y, z) of the vehicle calculated from each piece of route information, and the distance to the destination. Then, based on the route information retrieved by the route guidance unit 308, the display processing unit 302 displays the optimal route from the vehicle's traveling position to the driver's desired destination on a three-dimensional map using a locus mark or the like. , Icons indicating the direction in which the vehicle should travel. If necessary, the route information indicating the optimal route to the destination desired by the driver may be converted into voice data recognizable by the driver, and then output by the voice input / output device 104.

Next, a three-dimensional map creation process according to the present embodiment will be described with reference to FIG. 4 while associating with the functional configuration of the display processing unit 302 shown in FIG. However, here, according to the analysis result in the command analysis unit 300,
It is assumed that the data reading unit 309 extracts map information and attribute information corresponding to the area specified by the driver from the database.

In step 400, the data reading unit 3
In step 09, a three-dimensional model of the terrain is generated at a predetermined scale based on the altitude data included in the map information extracted from the database.

Next, in step 401, the height information determination unit 700 refers to the attribute information extracted together with the map information by the data reading unit 309, and determines the data structure of the shape data of a certain map element (ie, the presence or absence of height information). ).
At this time, when the height information determination unit 700 confirms the setting of the height information in the shape data, in step 403, the three-dimensional shape generation unit 701 determines that the three-dimensional shape represented by the shape data registered in the attribute information If the height information determination unit 700 confirms that the height information has not been set in the shape data, the two-dimensional shape generation unit 702 determines in step 404 that the attribute information has not been set. A three-dimensional model is created at a predetermined scale based on the two-dimensional shape represented by the registered shape data and the height information of the map information calculated from the altitude data included in the map information. Note that the series of processes from step 401 are similarly performed on other map elements registered in the attribute information, and finally, models of all map elements included in the map are created.

Then, in step 405, when the three-dimensional shape generation unit 701 or the two-dimensional shape generation unit 702 determines that the creation of the three-dimensional model of all map elements has been completed, in step 406, the synthesis unit 703 executes the above processing. The three-dimensional model of the terrain and the model of all map elements created by the above are arranged in a predetermined three-dimensional coordinate space. After that, the coordinate transformation unit 704 creates a perspective projection view from a predetermined viewpoint position, and further performs image processing such as hidden line elimination generally performed in projection processing of a three-dimensional object on the perspective projection view. In step 407, this is displayed on the display 102 as a three-dimensional map. In a three-dimensional map created by creating such a three-dimensional map, as shown in FIG. 5, a mountain 501 and a sea 503 created from elevation data are used.
And the image of the structure 502 and the like created from the shape data including the height information are individually and stereoscopically displayed. Will be displayed along the terrain.

As can be determined from FIG. 5, if the road is displayed along the undulations of the terrain even if it is slightly different from the actual situation, it has little effect on the driver's recognition of the road situation. Do not give. Therefore, regarding a road, there is a high possibility that shape data that does not include height information is registered in the attribute information. However, as in the three-dimensional map creation processing of FIG.
When the three-dimensional model is created by supplementing the height information that was not included in the shape data with the elevation data,
The following inconveniences may occur. That is, as shown in FIG.
01 mag is a road 60 along the canyon far from reality.
May be displayed as 2. Therefore, in order to avoid such inconvenience, in this embodiment, a three-dimensional model is created for a road by a model generation process as shown in FIG.

First, the gradient detecting section 705 determines in step 80
At 0, the start point of the road as shown in FIG. 6 N ₁ and the end point N
n at appropriate intervals, the division points N ₁ ,. . , Nn. Note that the division points N ₁ ,. . , Nn, a node of the road data included in the map information, an interpolation point set between nodes for use in road drawing, and the like may be used. After that, in step 801, the gradient detecting unit 705 determines each of the division points N ₁ ,. . , Slope m (i.e., division points Nk successive altitude difference D between Nk + 1) in Nn calculates, further, in step 802, detects the topographic change between the start point N ₁ and the end point Nn road . That is, the section in which the altitude data fluctuates rapidly (that is, the gradient m suddenly decreases by a predetermined value h or more, and again the predetermined value h
The section that increases above is determined as a valley area, and the other sections are determined as general road areas. Here, the predetermined value h
Is a reference value for determining a steep slope. In the present embodiment, a value appropriately determined based on a result of a road survey or the like is used. After that, in step 803, the height information setting unit 706 sets the actual elevation data at each division point as the height information of each division point included in the section determined as the general road area by the gradient detection unit 705. As the height information of each division point included in the section determined as the valley area by the gradient detection unit 705, the elevation data at the division point Nk, which is the start point of the valley area, is set. At this time, it is highly likely that discontinuous height information is set at the division points Nm, Nm + 1 at the boundary from the valley area to the general road area, so that the height information of the valley area changes smoothly. In addition, by using a spline function or the like, all division points Nk,. . . It is desirable to interpolate the height information of Nm + 1.

The above processing is completed, and all the division points N ₁ ,... Between the starting point N ₁ and the ending point Nn of the road are completed. . , Nn are set, in step 804, the three-dimensional synthesizing unit 7
03 are all division points N ₁ ,. . , Nn, and the road shape data registered in the attribute information, to create a three-dimensional model of the road at a predetermined scale.

If a three-dimensional model of a road is created by such a model generation process, the three-dimensional map displayed on the display 102 at step 407 in FIG. The image of the elevated overpass 601 is displayed. As shown in FIG. 9, in step 804, the dividing points N ₁ ,. . , Nn and the road shape data registered in the attribute information to create only a three-dimensional model of the road in the general road area.
At the division points Nk,. . . If the 3D model of the map element is created at a predetermined scale using the height information of Nm + 1 and the shape data of the appropriate map element (for example, viaduct or the like) registered in the attribute information, FIG.
As shown in the figure, a three-dimensional map displayed on the display 102 includes an image 10 such as an elevated road passing through the canyon 600.
00 can also be displayed.

By the way, with respect to map elements other than roads, even if shape data that does not include height information is registered in the attribute information, it is inconvenient if height information is simply supplemented by elevation data included in the map information. Likely to occur. For example, an unnatural three-dimensional map in which a building such as a building is displayed so as to stick to the terrain may be created.
Therefore, the default value of the height information of the map element is registered in the database for each attribute of the map element, and as shown in FIG. 11, the processing of step 1100 and step 1101 are newly added to the three-dimensional map creation processing of FIG. By incorporating the processing described above, such inconvenience can be solved. That is,
In step 1100, a default value of the height information of the attribute to which the map element whose height information has not been set in step 401 is searched, and if the default value is extracted in step 1100, in step 1101, A default value registered in the database is set as the height information of the map element. As a result, among the map elements for which the height information is not set in the attribute information, three of the map elements belonging to the attribute for which the default value of the height information is not registered.
In step 404, the two-dimensional shape is represented by the two-dimensional shape represented by the shape data registered in the attribute information and the height information of the map information calculated from the elevation data included in the map information by the two-dimensional shape generation unit 702 in step 404. The three-dimensional model of the map element belonging to the attribute in which the default value of the height information is registered is registered in the attribute information by the three-dimensional shape generation unit 701 in step 403. It is created based on the shape data and the height information set in step 1100.

As described above, since the navigation apparatus according to the present embodiment can add appropriate height information to the shape data of each map element, the height information of all map elements is not necessarily registered in the database. Even if it is not always done, a three-dimensional map without a sense of incongruity can be displayed. In other words, since it is not assumed that height information is registered for all map elements, there is a high possibility that a database of an existing map information system or a database of various map information systems to be provided in the future can be used as it is.

The description of the three-dimensional map creation processing according to the present embodiment is completed above, and the database update processing performed by the database update unit of the arithmetic processing unit will be described below with reference to FIG. The updating process of the database described here is a process executed at appropriate timings while the vehicle is running.

First, in step 1200, the running position of the vehicle stored in the trajectory storage unit 304 is obtained, and in step 1201, the node of the running position of the vehicle is associated with the road data included in the map information. The height information. Then, Step 1202
In the case where the gradient at the traveling position of the vehicle detected by the gradient sensor 112 is compared with the gradient of the traveling position of the vehicle calculated from the altitude data included in the map information, and the difference between the two exceeds a predetermined value. In step 1203, the altitude data associated with the node connected to the node at the travel position of the vehicle is corrected using the gradient at the travel position of the vehicle detected by the gradient sensor 112.

As described above, while the vehicle is running, the road data included in the map information registered in the database is automatically updated in accordance with the actual road conditions, so that the road data always matches the current traffic environment. 3D map can be displayed. That is, the navigation device according to the present embodiment can always provide the driver with the latest traffic information suitable for the current traffic environment even when the traffic environment is changed due to road maintenance or the like.

By the way, when the driver requests road information over a relatively wide area, the coordinate conversion unit 704 is used.
By setting the viewpoint position to be used at an appropriate altitude,
It is necessary to display a three-dimensional map viewed from an appropriate altitude position. In such a case, as shown in FIG.
A two-dimensional display of map elements such as small-scale buildings, and a three-dimensional display of only large-scale terrain, gives the driver a natural impression by returning (hereinafter, such an image is referred to as a pseudo image). 3D image). In order to realize such a function, as shown in FIG. 14, when the driver instructs to change the viewpoint position, in step 1400, the altitude of the viewpoint position instructed by the driver is compared with a predetermined value. If the altitude of the viewpoint position specified by the driver is equal to or less than a predetermined value, the same processing as the stereoscopic map generation processing described with reference to FIG. 4 is continued, and the viewpoint position specified by the driver is determined. If the altitude of the map element exceeds the predetermined value, in step 404, regardless of the presence or absence of the height information, the two-dimensional shape generation unit 702 performs the processing based on the shape data of each map element registered in the attribute information. What is necessary is just to create a two-dimensional model of all map elements.

In this way, the driver can display a normal three-dimensional map as shown in FIG. 15 or a three-dimensional map of a pseudo three-dimensional image as shown in FIG. The display state of the three-dimensional map can be freely switched. In order to emphasize road information required by the driver, a function of three-dimensionally displaying only a specific map element specified by the driver may be added.

[0039]

According to the image display device of the present invention, it is possible to display a three-dimensional map without a sense of incongruity regardless of the presence or absence of height information of each map element. In other words, it seems that the databases of various map information systems can be used as they are.

Further, if a function of automatically updating the database according to a change in the traffic environment is added to such an image display device, it is possible to display the latest three-dimensional map suitable for the current traffic environment.

That is, if such an image display device is introduced into the navigation system, the driver can be provided with the latest road information without performing any maintenance of the database.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a navigation device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a hardware configuration of an arithmetic processing unit in FIG. 1;

FIG. 3 is a diagram illustrating a software configuration of an arithmetic processing unit in FIG. 1;

FIG. 4 is a flowchart showing a flow of a three-dimensional map creation process according to one embodiment of the present invention.

FIG. 5 is an example of a three-dimensional map created by the three-dimensional map creation process of FIG. 4;

FIG. 6 is a diagram for explaining a model creation process when creating a three-dimensional model of an elevated road passed to a valley.

FIG. 7 is a diagram illustrating a functional configuration of a display processing unit in FIG. 3;

FIG. 8 is a flowchart illustrating a flow of a model creation process according to an embodiment of the present invention.

FIG. 9 is a flowchart illustrating a flow of a model creation process according to an embodiment of the present invention.

FIG. 10 is a three-dimensional model of an elevated road passed to a valley created by the model creation processing of FIG. 9;

FIG. 11 is a flowchart showing a flow of a three-dimensional map creation process according to an embodiment of the present invention.

FIG. 12 is a flowchart showing a flow of a database update process according to an embodiment of the present invention.

FIG. 13 is an example of a three-dimensional map of pseudo three-dimensional display.

FIG. 14 is an example of a normal three-dimensional map.

FIG. 15 is a flowchart showing a flow of processing for switching a display state of a three-dimensional map.

[Explanation of symbols]

 Reference Signs List 101 arithmetic processing unit 102 display 103 storage device 104 voice input / output device 105 input device 106 vehicle speed sensor 107 azimuth sensor 108 gyro 109 GPS receiving device 110 receiving device 111 LAN device 112 gradient sensor 1201 CPU 1202 DMA 1203 ROM 1204 RAM 1205 Drawing controller 1206 VRAM 1207 Color palette 1208 A / D converter 1209 SCI 1210 PIO 1211 Counter

Claims (7)

[Claims] An image display device for displaying an image of a map represented by the map information based on the map information, comprising: terrain data representing a three-dimensional shape of a ground surface; and a structure located on the ground surface. Three-dimensional data representing a three-dimensional shape including the height of a structure of an object, and the map information storing two-dimensional data representing a two-dimensional shape of a structure different from the structure, and the map information is stored in the map information. Terrain model generation means for generating a terrain model of a three-dimensional shape represented by the terrain data; two-dimensional generation of a model of each of the two-dimensional structures represented by each of the plane data stored in the map information A model generation unit, a three-dimensional model generation unit that respectively generates a model of each of the three-dimensional structures represented by the three-dimensional data stored in the map information, and a three-dimensional model generation unit that generates the three-dimensional model. Combining means for arranging the model of each structure and the model of each structure generated by the three-dimensional model generating means on the terrain model generated by the terrain model generating means; and an image of the map to be displayed. An image display device, wherein the synthesizing unit includes a projection unit that creates a projection view by projecting the terrain model on which the model of each of the structures is arranged on a projection plane determined with respect to an arbitrary viewpoint position. . 2. The image display device according to claim 1, wherein the plane data stored in the map information indicates a two-dimensional shape of the ground surface at a point where a predetermined structure is located. Detecting means for detecting an altitude and setting the height of the predetermined structure, wherein the two-dimensional model generation means replaces the model of the predetermined structure having a two-dimensional shape with the predetermined structure detected by the detection means. Generating a model of the predetermined structure having a three-dimensional shape represented by the height of the structure and plane data representing the two-dimensional shape of the predetermined structure stored in the map information. Image display device. 3. The image display device according to claim 1, wherein: a receiving unit that receives an instruction to specify the viewpoint position; and the viewpoint position indicated by the instruction received by the receiving unit exceeds a predetermined altitude. In this case, the three-dimensional model generating means replaces the model of each structure of the three-dimensional shape with a two-dimensional shape obtained by ignoring a height included in each three-dimensional data stored in the map information. An image display device for generating a model of each of the above structures. 4. The image display device according to claim 1, wherein for each section determined according to the type of the structure, a database in which shape data commonly representing a three-dimensional shape of the structure belonging to the section is registered. A data acquisition unit that searches the database and retrieves shape data of a section to which a structure in which the plane data stored in the map information represents a two-dimensional shape, and the two-dimensional model generation unit includes: The data acquisition means retrieves from the database in place of the model of the two-dimensionally structured structure belonging to the section in which the shape data is registered in the database in the structure in which the stored plane data represents the two-dimensionally shaped structure. An image display device, wherein a model of the three-dimensional structure represented by the shape data is created at an arbitrary scale. 5. An image display device for displaying an image of a map represented by the map information based on the map information, the terrain data representing a three-dimensional shape of the ground surface, and representing a route of a road on the ground surface. Storage means for registering the map information storing route information and shape data representing a three-dimensional shape of a predetermined structure; generating a three-dimensional shape topographic model represented by the topographic data stored in the map information Terrain model generating means for generating, a structure model generating means for generating a model of the structure having a three-dimensional shape represented by the shape data stored in the storage means, and a road represented by route information stored in the map information Detection means for detecting a change in the shape of the terrain model generated by the terrain model generation means along the path of the terrain model; and When a concave portion having an incline is detected, the model of the structure generated by the structure model generating means is converted to the topography generated by the terrain model generating means so as to be bridged over the concave portion of the terrain model. A combining unit arranged on a three-dimensional model, and a projection view in which the combining unit projects the terrain model on which the model of the structure is arranged on a projection plane determined with respect to an arbitrary viewpoint position as an image of the map to be displayed. An image display device, comprising: a projection unit that creates the image. 6. A navigation system for three-dimensionally displaying a map represented by the map information based on the map information, wherein the image display device displays an image of the map represented by the map information based on the map information. Terrain data representing a three-dimensional shape of the ground surface, three-dimensional data representing a three-dimensional shape including the height of a structure of a structure located on the ground surface, and two-dimensional data of a structure different from the structure. The map information storing plane data representing a three-dimensional shape; a terrain model generating means for generating a three-dimensional shape terrain model represented by the terrain data stored in the map information; Two-dimensional model generating means for respectively generating a model of each of the two-dimensional structures represented by the two-dimensional data represented by the two-dimensional data; and the three-dimensional shape represented by each three-dimensional data stored in the map information. Three-dimensional model generation means for respectively generating a model of a structure, a model of each structure generated by the two-dimensional model generation means and a model of each structure generated by the three-dimensional model generation means, A synthesizing unit arranged on the terrain model generated by the terrain model generating unit; and, as an image of the map to be displayed, the terrain model on which the synthesizing unit arranges the model of each structure is determined for an arbitrary viewpoint position A navigation system, comprising: projection means for creating a projection view projected on a projection surface. 7. The navigation system according to claim 6, wherein a detecting means for detecting a gradient of a traveling path of the vehicle, and a gradient of a three-dimensional shape of the ground surface represented by the terrain data stored in the map information is: An image processing apparatus, comprising: a correction unit that corrects the topographic data stored in the map information so as to match a gradient of the traveling path detected by the detection unit.