JP2004354538A - Method and device for generating polygon data of map or the like, and display device for polygon data of map or the like - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polygon data generation method capable of automatically generating polygon data of a map or the like. <P>SOLUTION: The method of generating polygon data of a map or the like includes the following steps: a step to discriminate an inner polygon included in an outer polygon; a step to make the drawing information for drawing the outer polygon and that for the inner polygon different; and a step to connect the inner polygon and the outer polygon by a line drawn from a preset position of the inner polygon. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for generating polygon data such as a map displayed on a navigation device and the like, a generation device for the same, and a display device for the same.
[0002]
[Prior art]
The navigation device detects the current position of the vehicle, reads map data around the vehicle position from a storage medium such as a DVD or a hard disk (HDD), draws a map on a display, and superimposes a vehicle mark on the map. draw. When the current position changes due to the movement of the vehicle, the map is scrolled or the vehicle mark on the map is moved in accordance with the change to present the map information around the vehicle position to the user in an easy-to-understand manner.
[0003]
The map data includes, in addition to roads and facilities, polygon data for representing land-based terrain such as islands and water-based terrain such as oceans, lakes, and rivers. By using such polygon data, the display of the map is three-dimensional, and the speed of scrolling the map screen and the like is increased.
[0004]
When a water-based area includes a land-based area, a land-based area includes a water-based area, and when the terrain is complicatedly intertwined, the generation of polygon data and the drawing method thereof become complicated. For example, when displaying an island in the sea, there are the following two methods. In the first method, as shown in FIG. 8A, a blue-based polygon 100 representing a sea area and a land-colored polygon 110 representing an island area are prepared independently, and a map is prepared. When a screen is displayed, a sea polygon 100 is first drawn, and then an island polygon 110 is drawn thereon.
[0005]
In the second method, as shown in FIG. 8B, polygon data is generated such that the island polygon 130 is omitted from the sea polygon 120. Polygon data consists of vector information for connecting discrete element points on coordinates, direction information for connecting from the starting point (element point) to the ending point (element point) on coordinates, and colors related to polyline and polygon colors. Information. The direction information can set a polygon drawing condition depending on the direction. For example, when the direction connecting the start point to the end point is counterclockwise with respect to the traveling direction, the inside of the polygon is drawn with the color specified by the color information. It is possible to make an agreement (algorithm) such that drawing is not performed in the inside. In the case of FIG. 8B, the direction information of the island polygon 130 is set clockwise, the direction information of the sea polygon 120 is set counterclockwise, and the start point (and end point) 140 of the island polygon 130 and the sea are set. Polygon data that connects the start point (and end point) 150 of the polygon 120 with a polyline 160 is generated. When polygon data is drawn, the island polygon 130 is hollowed out, and the sea polygon 120 is drawn in a bluish color. In general, most of the display by the navigation device is a land-based color. Therefore, when a water-based color is not drawn, a land-based color is often used. Since the island polygon 130 is not drawn in a water-based color, it is represented in a land-based color. As described above, the sea-based and land-based maps are displayed by generating the polygon data in which the island polygon 130 is drawn out of the sea polygon 120 with one stroke. This method is described in Patent Document 1, for example.
[0006]
[Patent Document 1]
JP-A-11-258984
[Problems to be solved by the invention]
However, the above-described conventional polygon data generation and drawing method has the following problems. In the case where the sea polygon 100 and the island polygon 110 are drawn by the first method, since two drawing operations are required for one screen display, there is a problem that map display and screen scrolling are slow. . Further, since the data of the sea polygon 100 and the data of the island polygon 110 are required, the memory capacity is increased. Furthermore, the sea polygon 100 must be drawn before the island polygon 110, and it is very complicated to associate such a drawing order with each polygon.
[0008]
On the other hand, the second method is effective in reducing the memory capacity and increasing the speed of map display and the like, but all operations to connect the sea polygon 120 and the island polygon 130 by the polyline 160 are manual. Since the work was performed, a great deal of time and effort was required. In particular, when the shape, size, and number of polygons are various, the positions of the polylines connecting the outer polygon and the inner polygon are also different, and in some cases, the line of the polyline 160 is displayed. Sometimes an error occurred.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a method for generating polygon data capable of automatically generating polygon data such as a map.
Further, the present invention relates to a generating device for automatically generating polygon data and a display device for displaying the polygon data.
[0010]
[Means for Solving the Problems]
A method for generating polygon data such as a map according to the present invention includes a step of identifying an inner polygon included in an outer polygon, a step of drawing information for drawing the outer polygon, and a step of drawing information for drawing the inner polygon. A step of making the drawing information different; and a step of connecting the inner polygon and the outer polygon with a line drawn from a preset position of the inner polygon. By using such steps, it is possible to automatically generate polygon data for polygons having an inclusion relationship. Therefore, it is possible to significantly reduce labor and time as compared with the conventional manual operation, and as a result, it is possible to reduce the cost of producing polygon data. Further, the work required for verifying the polygon data can be reduced.
[0011]
Preferably, the drawing information includes direction information on a direction connecting the start point to the end point of the polygon. This direction information determines the polygon drawing conditions. For example, if the direction information is clockwise, polygon drawing may not be performed, and if the direction information is counterclockwise, polygon drawing may be performed.
[0012]
The outer polygon is either a land-based or water-based polygon, and the inner polygon is either a land-based or water-based polygon. Polygon data can be automatically generated easily even if the terrain is complicated in land and water.
[0013]
The polygon data generating apparatus according to the present invention includes a memory for storing a program that defines a method for generating the polygon data, a first storage unit for storing polygon data before processing a map or the like, and the first storage. There is provided processing means for processing the polygon data read from the means in accordance with the program in the memory, and second storage means for storing the polygon data processed by the processing means.
[0014]
A display device according to the present invention includes a storage device for storing polygon data generated by the polygon data generation device, a display unit, and display control means for displaying the polygon data read from the storage device on the display unit. And By using the polygon data automatically generated by the present invention, one screen display can be performed by one drawing, and the high-speed display and scrolling of the map screen can be maintained.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a method of generating polygon data according to the embodiment of the present invention will be described with reference to the flowchart shown in FIG. Here, a navigation device that is typical as a map display device will be described as an example.
[0016]
First, original polygon data before processing included in a figure to be processed is extracted (step S101). In the navigation device, for example, as shown in FIG. 2, when the vehicle position 210 is displayed at the center of the display 200, the map screen around the vehicle position is divided into a plurality of M rows × N columns. . Each map leaf 220 includes, at its vertices A1, A2, A3, and A4, positional information of latitude and longitude, and polygons such as maps, roads, facilities, and the like arranged inside the map leaf are calculated from those vertices. Is specified by relative position information. Here, in order to facilitate the generation of the polygon data, the polygon for each leaf is to be processed.
[0017]
Next, the inclusion relation of polygons included in each figure is obtained (step S102). As shown in FIG. 3, for example, the polygon inclusion relationship includes a land-based polygon (inner polygon P2) such as an island within a water-based polygon (outer polygon P1) such as a sea, a lake, or a swamp. On the contrary, the land-based polygons include the water-based polygons, or the water-based polygons and the land-based polygons are in a complicated relationship. That is.
[0018]
As shown in FIG. 3, lines parallel to the Y axis are drawn from X1, X2, X3,... Xn at intervals equal to the X axis, and the intersections between the element points of the polygons P1, P2 are determined (step S103). The number of intersections always exists even (0, 2, 4,... N). Among the intersections, numbers are assigned in ascending order of the value of Y (step S104). For example, the line from X1 intersects polygon P1 and the number of intersections is two, and the lines from X2 and X3 intersect polygons P1 and P2 and the number of intersections is four.
[0019]
Next, it is determined whether the number of intersections is greater than two (step S105). If the number of intersections is two or less, there is no inner polygon (step S107). That is, a plurality of polygons do not exist on the line, and therefore there is no polygon inclusion relation. If the number of the intersections is more than two, a plurality of polygons exist on the line. In this case, the area immediately below the odd number at the intersection is the inner polygon (step S108). In the example of FIG. 3, the line from X2 and X3 has four intersections, and the area immediately below the odd number “3” is the inner polygon P2. Conversely, the area immediately below the even number “4” is the outer polygon P1.
[0020]
Next, the direction information for connecting the element points of the outer polygon P1 and the direction information for connecting the element points of the inner polygon P2 are set in opposite directions (step S109). For example, if the algorithm is to draw a polygon in the color specified by the color information when the polygon is counterclockwise in the traveling direction, if the outer polygon P1 is water-based, the direction information is counterclockwise. And if the inner polygon P2 is a land-based polygon, the direction information is set clockwise.
[0021]
Next, as shown in FIG. 3 (b), a perpendicular V is drawn downward from the leftmost element point S2 of the inner polygon P2, and an intersection S1 with the polygon that intersects first is determined and one stroke is drawn ( Step S110). The element point S2 is a start point and an end point of the inner polygon P2, and the intersection S1 is a start point and an end point of the outer polygon P1. In other words, the polygon data of the polygon P1 including the polygon P2 is written in one stroke so as to rotate clockwise from the start point S2 to reach the end point S2, and to rotate counterclockwise from the perpendicular V to the end point S1 starting from the intersection S1. By setting the direction information of the polygon P1 and the direction information of the polygon P2 to be opposite, a hollow polygon P2 can be formed in the polygon P1. According to such a processing procedure, it is possible to automatically generate polygon data having an inclusion relationship.
[0022]
FIG. 4A is a display example of polygon data automatically generated according to the above processing procedure. Since the outer polygon P1 is a water system such as the sea, a bluish color is set in the color information of the polygon data. Since the inner polygon P2 is in a hollow state and does not represent a water-based color, a land-based color is displayed. Further, the perpendicular V (polyline) connecting the outer polygon P1 and the inner polygon P2 does not appear on an actual screen by being set to the same color as the color of the water system.
[0023]
FIG. 4B is a display example when the setting of the direction information of the outer polygon P1 and the inner polygon P2 is reversed. For example, when the outer polygon P1 is land-based and the inner polygon P2 is water-based, the inner polygon P2 is displayed in blue. Further, a perpendicular line (polyline) connecting the polygons P1 and P2 does not appear on an actual screen because it has the same color as the land-based color.
[0024]
Next, an example in which a plurality of polygon data are included is shown in FIG. In this example, it is assumed that an island polygon 310 is included in the sea polygon 300, and a lake polygon 320 is included in the island polygon 310. According to the processing procedure of FIG. 1 described above, the inclusion relation of the polygons 300, 310, and 320 is obtained. That is, when the number of intersections is larger than 2, the area immediately below the odd number (here, 3 and 5) of the intersection is determined to be an inner polygon. That is, the island polygon 310 is set as the inner polygon. The area immediately below the even number (here, 4 and 6) of the intersection is determined as the outer polygon. That is, the lake polygon 320 and the sea polygon 300 are regarded as outer polygons. Next, direction information when connecting the element points of the sea polygon 300, the island polygon 310, and the lake polygon 320 is set to be opposite to each other. The direction information of the sea polygon 300 and the lake polygon 320 is set counterclockwise, and the direction information of the island polygon 310 is set clockwise.
[0025]
Next, a perpendicular 322 is drawn from the leftmost element point 321 of the lake polygon 320, and an intersection 323 with the polygon 310 is obtained. Similarly, a perpendicular 312 is drawn from the leftmost element point 311 of the island polygon 310. Then, an intersection 313 with the polygon 300 is obtained. In this way, polygon data of a hollow polygon 310 formed in the sea polygon 300 and a lake polygon 320 formed in the island polygon 310 is generated.
[0026]
FIG. 5B is a drawing example of the polygon data of FIG. 5A. The hatched area is represented as a water-based color, and the island area is a state where the water-based color is not applied, that is, land. It becomes the color of the system. Here, the perpendicular line (polyline) 322 connecting the polygon 320 to the polygon 310 has the same color as the island region unless the color is a land-based color, that is, a water-based color. In addition, the perpendicular (polyline) 312 connecting the polygon 310 and the polygon 300 has the same color as that of the sea area by using a water-based color.
[0027]
Next, FIG. 6 shows an example of the configuration of an automatic polygon data generation apparatus that performs the method for generating polygon data according to the present embodiment. The automatic generation device 400 includes an image processing processor 410, a ROM 420, a RAM 430, and a storage device 440. The ROM 420 stores a program that defines a procedure for automatically generating the polygon data shown in FIG. The storage device 440 is preferably a hard disk capable of rewriting data, and stores original polygon data before processing. The image processor 410 reads polygon data of the target figure from the storage device 440 according to the program in the ROM 420 and stores the polygon data in the RAM 430. Then, polygon data is automatically generated according to the processing procedure shown in FIG. 1 and stored in the storage device 440. Conventionally, when polygons are in an inclusive relationship, polygon data has been manually created. According to the present invention, it is possible to automatically generate polygon data of such polygons. It is possible to reduce the production time and the cost.
[0028]
Next, FIG. 7 schematically shows a navigation device using polygon data automatically generated according to the present embodiment. The navigation device 500 includes a processing main body 510 having a navigation function unit and an audio function unit, a position detection unit 520 for detecting the position of the own vehicle by a GPS receiver or the like, an input unit 530 for inputting an instruction from a user, and a road. , A storage device 540 for storing polygon data of an image necessary for navigation display of a map, a facility, etc., an audio output unit 550 provided with a speaker and the like, and an image output unit 560 provided with a display and the like.
[0029]
The automatically generated polygon data is stored in the storage device 540. When displaying a map around the own vehicle position by the navigation function unit, polygon data for each figure is read from the storage device 540 and displayed on the display. Along with the movement of the vehicle position, the map display on the display is scrolled, and necessary polygon data of the map is sequentially read. The polygon data automatically generated according to the present embodiment can display one screen display once by, for example, hollowing out land-based polygons even when land-based polygons and water-based polygons have an inclusion relationship. This can be done by drawing, and the speed of scrolling and map display can be increased. In addition, since it is not necessary to define the drawing order of land-based polygons and water-based polygons as in the past, complicated work for associating them can be omitted, and water-based and land-based polygons can be omitted. Since it is not necessary to separately provide polygon data, the data capacity can be reduced, and as a result, the capacity of the storage device can also be reduced.
[0030]
Although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to the specific embodiment, and various modifications and changes may be made within the scope of the present invention described in the appended claims. Changes are possible. For example, in the above embodiment, the polygon is drawn when the direction is counterclockwise. However, the present invention is not limited to this, and the polygon may be drawn when clockwise.
[0031]
Further, in the above embodiment, an example is shown in which water-based and land-based polygons are in an inclusive relationship. However, the present invention can also be applied to the display of roads, facilities, and other terrain. Although the navigation device is exemplified as the map display device, the invention is not limited thereto, and a computer or the like having a display function of a map or the like may be used.
[0032]
【The invention's effect】
As described above, according to the present invention, the step of identifying the inner polygon included in the outer polygon, the step of making the drawing information for drawing the outer polygon different from the drawing information for drawing the inner polygon, Connecting the inner polygon and the outer polygon with a line drawn from a preset position of the inner polygon, thereby automatically generating polygon data for the polygons having an inclusion relationship. It becomes. Therefore, it is possible to significantly reduce labor and time as compared with the conventional manual operation.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a processing flow of an automatic polygon data generation method according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining a figure displayed on a display;
FIG. 3A is a diagram illustrating determination of inclusion relation of polygon data, and FIG. 3B is a diagram illustrating setting of direction information of inner and outer polygon data.
FIG. 4 is a diagram showing a display example of automatically generated polygon data.
FIG. 5 is a diagram showing an example of other polygon data in which water-based polygon data and land-based polygon data have an inclusion relationship.
FIG. 6 is a block diagram illustrating an example of an automatic polygon data generation device.
FIG. 7 is a diagram showing a configuration of a navigation device that displays automatically generated polygon data.
FIG. 8 is a diagram illustrating the generation and display of conventional polygon data.
[Explanation of symbols]
200 display 210 own vehicle mark 220 figure P1 outside polygon P2 inside polygon 300, 310, 320 polygon 400 polygon automatic generation device 500 navigation device

Claims (6)

A method for generating polygon data such as a map,
Identifying an inner polygon contained by the outer polygon;
A step of making the drawing information for drawing the outer polygon different from the drawing information for drawing the inner polygon;
Connecting the inner polygon and the outer polygon by a line drawn from a preset position of the inner polygon;
A method for generating polygon data such as a map having a map. 2. The polygon data generation method according to claim 1, wherein the drawing information includes direction information on a direction connecting a start point to an end point of the polygon, and the direction information determines a drawing condition of the polygon. 3. The polygon data generation according to claim 1, wherein the outer polygon is a land-based or water-based polygon, and the inner polygon is a land-based or water-based polygon. 4. Method. 2. The polygon data generation method according to claim 1, wherein the preset position is a leftmost position or a rightmost position of an inner polygon. A memory for storing a program that defines the polygon data generation method according to claim 1,
First storage means for storing polygon data before processing such as a map,
Processing means for processing the polygon data read from the first storage means according to a program in the memory;
And a second storage unit for storing the polygon data processed by the processing unit. A storage device for storing polygon data generated by the polygon data generation device according to claim 5,
A display unit,
A display control means for displaying the polygon data read from the storage device on the display unit.

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