JP2002230589A - System and method for processing building data into polygon, and program for processing building data into polygon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for processing building data into a polygon capable of effectively generating polygon data from line data representing an outline of a building while minimizing omission or the like of data. SOLUTION: A polygon data generating part 11 synthesizes a plurality of building line data by building kinds included in building line data by building kinds 21 while neglecting a kind of the building once by a line data synthesizing part 11a, and generates polygon data (building polygon data 22) corresponding to each of the line data on the basis of all the synthesized line data by a part for processing into a polygon 11b. A point data generating part 12 generates point data (point data 23 for determining a building kind) for determining a kind of the building for each of the line data on the basis of the plurality of line data by building kinds. An attribute imparting part 13 determines the kind of the building corresponding to each of the polygon data on the basis of position relation between each of the polygon data generated by the polygon data generating part 11 and each of the point data generated by the point data generating part 12, and imparts building kind information to each of the polygon data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to building data used in a Geographic Information System (GIS) and the like, and more particularly to building data for generating polygon data based on line data representing the outline of a building. The present invention relates to a polygonization system, a method thereof, and a building data polygonization program.

[0002]

2. Description of the Related Art In recent years, local governments in various places have been promoting the digitization of business, and management of geographic information using a geographic information system (GIS) has become essential. In such a geographic information system (GIS), building data is generally used as a part of the geographic information data, and an enormous amount of building data created up to now by each local government is effectively used. It is desired.

When municipalities in various places perform surveys and create maps (including building data), work is performed based on the public survey work regulations of the Ministry of Construction, which are prescribed by the Geographical Survey Institute of the Ministry of Construction. ing. The Ministry of Construction Public Surveying Work Regulations stipulates that building data as digital mapping data (numerical information created on a computer) be created using line data. Note that the line data represents the outline of a building (shape, position, etc.) as a set of vertex strings connected by line segments.

In a geographic information system, when building data is used as geographic information data, it is necessary to distinguish between inside and outside of a building, determine the inclusion relationship between buildings, calculate the distance between buildings, and calculate the distance between buildings. It is indispensable that the building data is polygon data (data expressed as a closed polygon (polygon)) in order to make a relationship with various geographic information.

[0005] Some conventional geographic information systems incorporate a polygon processing for generating polygon data by simply connecting the start and end points of line data.

[0006]

However, the line data defined by the Ministry of Construction's Public Surveying Work Regulations does not necessarily require that the start point and the end point match, and are closed as polygons. Not contain a lot of data. Therefore, in the above-described conventional polygon processing, all line data cannot be converted into polygons, and there is a problem that many polygon data are lost.

FIGS. 7A and 7B are diagrams showing an example of building data which is difficult to make into polygons. As shown in FIG. 7A, the building structure includes an L-shaped first building 25 and a second building 26 adjacent to the first building 25.
The first building 25 and the second building 26 are different types of buildings (the first building 25 belongs to the type of “general building”, and the second building 26 is called “general non-walled building” such as a hut. Line data), and the corresponding line data is also distinguished for each type of building. Specifically, the first
The line data corresponding to the building 25 is represented by six line segments (shown by thick lines in FIG. 7A) (A1-A2, A2-
A3, A3-A4, A4-A5, A5-A6, A6-A
1) Represented as connections between each other. In addition, the line data corresponding to the second building 26 includes two line segments (shown by thin lines in FIG. 7A) using the outer wall of the first building 25 (B1-B2, B2-B3) are represented as a link only.

In this case, when the polygon data is generated by simply connecting the start point and the end point of each line data corresponding to the first building 25 or the second building 26 by the above-described conventional polygon conversion processing, With respect to the line data corresponding to the building 25, polygon data is generated without any problem because the start point and the end point match (see reference numeral 25 'in FIG. 7B). , The start point (B1) and the end point (B3)
Does not match, if the start point (B1) and the end point (B3) are connected as they are, polygon data having a shape different from the expected outer shape will be generated (FIG. 7 (b)). )).

As described above, in the above-described conventional polygon processing, it is difficult to generate complete polygon data based on line data whose start point and end point do not coincide with each other. In order to create complete polygon data, a large amount of data needs to be manually checked by visual confirmation or the like, and there is a problem that much work time and cost are required.

[0010] The present invention has been made in view of such a point, and it is possible to efficiently generate polygon data from line data representing the outline of a building while minimizing data loss and the like. An object of the present invention is to provide a building data polygonization system, a method thereof, and a building data polygonization program.

[0011]

According to a first aspect of the present invention, there is provided a building data polygonizing system for generating polygon data based on line data representing the outline of a building. A polygon data generating unit that combines a plurality of line data for each of the building types, and generates polygon data corresponding to each of the line data based on all the combined line data.
A point data generation unit that generates point data for determining the type of building for each line data based on the plurality of line data for each building type; each of the generated polygon data and each of the point data; And determining the type of the building corresponding to each of the polygon data based on the positional relationship with the polygon data, and based on the determination result, providing an attribute assigning unit that assigns the type information of the building to each of the polygon data. A feature is to provide a building data polygonizing system.

[0012] In the above-mentioned first solution,
It is preferable that the polygon data generation unit generates polygon data corresponding to each of the line data by connecting a start point and an end point of all the synthesized line data and an intersection of the line data to each other. Further, the point data generation unit may generate, as the point data, an internal point of each line data and / or
Alternatively, it is preferable to generate a point on the circumference.

According to a second aspect of the present invention, there is provided a building data polygonizing method for generating polygon data based on line data representing the outline of a building. A step of combining a plurality of line data and generating polygon data corresponding to each of the line data based on all the combined line data; and Generating point data for determining the type for each line data;
Based on the positional relationship between the generated polygon data and the point data, a type of a building corresponding to the polygon data is determined, and based on the determination result,
Adding building type information to each of the polygon data.

According to a third aspect of the present invention, there is provided a building data polygonizing program for generating polygon data based on line data representing the outline of a building.
A step of combining a plurality of line data for each building type distinguished for each building type and generating polygon data corresponding to each of the line data based on all the combined line data; Based on another plurality of line data, a procedure for generating point data for determining the type of building for each of the line data, and based on a positional relationship between the generated polygon data and the point data. Determining the type of the building corresponding to each of the polygon data, and, based on the determination result, causing the computer to execute a procedure of adding the type information of the building to each of the polygon data. Provides a data polygonization program.

According to the present invention, a plurality of line data for each building type classified for each building type are synthesized, and based on all the synthesized line data, polygon data corresponding to each line data is converted. On the other hand, based on a plurality of line data for each building type, point data for determining the type of building is generated for each of the line data, and the generated polygon data and the point data are generated. Since the type information of the building is added to each polygon data based on the positional relationship, polygon data is efficiently generated from line data representing the outline of the building while minimizing data loss. be able to.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a building data polygonization system 10 according to the present embodiment generates polygon data based on line data representing the outline of a building. A point data generation unit 12 and an attribute assignment unit 13 are provided. In the building data polygonization system 10, a building including a plurality of line data for each building type classified by building type (for example, a general building, a robust building, a general no-wall building, a robust no-wall building, and the like). Building line data 21 for each type is input, and building polygon data 24 with a building type attribute including polygon data (polygon data holding the type information of the building) corresponding to each line data is output. In addition,
A plurality of line data for each building type classified for each building type is included in the building line data 21 for each building type.
General building line data 21a, robust building line data 2
1b, the general unshaded house line data 21c and the robust unshaded house line data 21d are separately stored.

Here, the polygon data generating section 11 has a line data synthesizing section 11a and a polygonizing section 11b. After combining multiple line data once ignoring the type of building,
The polygonizing unit 11b generates polygon data corresponding to each line data based on all the synthesized line data. The polygonization unit 11b connects the start point and the end point of all the synthesized line data and the intersection of the line data to each other,
Polygon data corresponding to each line data is generated.
The plurality of polygon data generated in this way is input to the attribute assigning unit 13 as building polygon data 22.

Further, the point data generation unit 12 generates point data for determining the type of building based on a plurality of line data for each building type included in the building line data 21 for each building type. To be generated. Here, as each point data, an internal point (for example, a pseudo centroid point) and a perimeter point are generated based on a vertex sequence of each line data. The point data generated in this way is input to the attribute assignment unit 13 as building type determination point data 23.

Further, the attribute assigning section 13 corresponds to each polygon data based on the positional relationship between each polygon data generated by the polygon data generating section 11 and each point data generated by the point data generating section 12. The type of building to be performed is determined, and based on the determination result, the type information of the building is added to each of the polygon data. Specifically, the attribute assigning unit 13 finds point data (point data located inside or on the circumference of each polygon data) included in each polygon data, and extracts the type information of the building held by the point data. Assigned to each polygon data.

Next, the operation of the present embodiment having such a configuration will be described. Here, a case where polygon data is generated based on line data corresponding to the building structure shown in FIG. 2 will be described as an example.

Here, the building structure shown in FIG.
(a) It is the same as that shown in (a), The L-shaped 1st building 25 and the 2nd building 2 adjacent to this 1st building 25
It consists of six. The first building 25 is a “general building”
And the line data is composed of six line segments (shown by bold lines in FIG. 2) (A1-A2, A2-A3, A3-A
4, A4-A5, A5-A6, A6-A1). Further, the second building 26 is a “general non-walled building”, and its line data is composed of two line segments (FIG. 2).
(B1-B2, B2-B3)
Only represented as a concatenation. These first buildings 2
The line data corresponding to the fifth and second buildings 26 are stored separately for each type of building, and are included in the general building line data 21a and the general wallless line data 21c, respectively.

FIGS. 3 (a) and 3 (b) are views showing examples of general building line data 21a and general non-wall building line data 21c, respectively. As shown in FIG. 3A, the line data corresponding to the first building 25 included in the general building line data 21a is a series of line segments (A1-A) connected to each other.
2, A2-A3, A3-A4, A4-A5, A5-A
6, A6-A1), and the coordinates of each vertex (“(x1, y1)”, “(x2, y2)”,..., “(X1, y
1) "). As shown in FIG. 3 (b),
The line data corresponding to the second building 26 included in the general unbarred line data 21c is the number of vertices (“3”) included in a series of line segments (B1-B2, B2-B3) connected to each other. And the coordinates of each vertex (“(x1, y1)”, “(x2, y
2) ”and“ (x3, y3) ”).

Here, the building data polygonization system 10 shown in FIG. 1 takes in the general building line data 21a and the general non-wall building line data 21c as shown in FIGS. 11, the following processing is performed by the point data generation unit 12 and the attribute assignment unit 13.

First, the general building line data 21 is generated by the line data synthesizing section 11a of the polygon data generating section 11.
After combining a plurality of line data for each building type included in the line data 21a and the general uninhabited building line data 21c, once ignoring the building type, the polygonization unit 11b performs a synthesis based on all the synthesized line data. Then, polygon data corresponding to each line data is generated. It should be noted that the polygonization unit 11b is a first building 2 of the building structures shown in FIG.
5, the start point and the end point are connected to each other, and the existence of the intersection with the line data corresponding to another building (the second building 26). And if they exist (here B1 and B3), split the line segment by that point,
Polygon (polygon) (A1-A2, A2-A3, A3-
B1, B1-A4, A4-B3, B3-A5, A5-A
6, A6-A1) to generate closed polygon data. For the line data corresponding to the second building 26 (line data whose start point and end point do not match), the polygonization unit 11b sets the start point and the end point to points on line segments (intersection points between line data points). ) Is extracted, and line segment data (A4-B3, B1-A4) between the corresponding intersections among the line data is supplemented with the original line data (B1-B2, B2-B3). By connecting, polygons (polygons) (B1-B2, B2-
B3, A4-B3, and B1-A4) are generated as closed polygon data.

FIG. 4 is a diagram showing an example of the building polygon data 22 including the polygon data generated in this way. The format of the polygon data (notation method)
Is different depending on the geographic information system (GIS), an example is shown here as a reference for explaining the present invention. As shown in FIG. 4, the building polygon data 22 is composed of a polygon data body 22a containing information on the basic structure of polygon data, and line segment data containing information on each line constituting each polygon data contained in the polygon data body 22a. 22b. Among these, the polygon data body 22a indicates the number of line segments constituting each polygon data (for example, “8” in the case of the first building 25, “4” in the case of the second building 26), Identifier of each line segment constituting each polygon data (for example, “A1-A2”, “A2-A3”,..., “A6-A1” in the case of the first building 25, and in the case of the second building 26 Include “B1-B2”, “B2-B3”, “A4-B
3 ”,“ B1-A4 ”), and the line segment data 2
2b includes an identifier of each line segment (eg, “A1-A2”), the coordinates of the start point of each line segment (eg, “(x1, y1)”), and the coordinates of the end point (eg, “(x2, y2)”). In.

On the other hand, the point data generation unit 12
Based on a plurality of line data for each building type included in the building type-specific building line data 21, point data for determining a building type is generated for each line data. Specifically, for example, for the line data corresponding to the first building 25, as the point data, the pseudo centroid G _A (see FIG. 2) and the perimeter point L _A (see FIG. 2) of the vertex row of each line data ). Also, the line data corresponding to the second building 26, as point data, the pseudo-center-of-gravity point G _B vertex string of each line data
Generating a (see FIG. 2) and the circumferential upper point _{L B} (see FIG. 2).

Here, the pseudo centroid point is a point obtained by correcting the position of the centroid point calculated from the vertex position so that the centroid point is included in the closed area constituted by the line data. Further, the circumferential point is an intermediate point of a line segment constituting the line data.

Finally, the attribute assigning unit 13
Based on the positional relationship between each piece of polygon data generated by the polygon data generation unit 11 and each piece of point data generated by the point data generation unit 12, point data included in each piece of polygon data (inside each polygon data or (Point data located on the circumference) is found, and the type information of the building held by the point data is added to each polygon data. Specifically, for example,
Both pseudo center of gravity G _A and circumferential upper point L _A corresponds to the first building 25, since it is included in the first polygon data included in the building polygon data 22 shown in FIG. 4, the pseudo center of gravity G type information of the building _a and the peripheral upper point L _a holds (here, "general building") to impart to the polygon data. Moreover, neither the pseudo gravity point G _B and the circumferential upper point L _B corresponding to the second building 26, because it is included in the second polygon data included in the building polygon data 22 shown in FIG. 4, the pseudo center of gravity point _{G B} and the circumferential upper point _{L B}
Type information (here "General Mukaisha") stored by
Is added to the polygon data.

In the example of FIG. 2, the type information of the building can be given only from the inclusion relation of the pseudo center of gravity, but as shown in FIG. 8, two line data (C1-C2, C2-C
3) and in the example of the building 27 (crossing corridor type building connecting the two buildings 28 and 29) represented by (D1-D2, D2-D3), the pseudo centroid G _C calculated from C1, C2, and C3. and D1, D2, none of the pseudo center of gravity G _D calculated from D3, located outside the polygon polygon generated by the data generating unit 11 (polygon) 27. Therefore, in this case, the line data (C1-C2,
Used for C2-C3) which is one of the peripheral upper point _{L C} or is one _{L D} of the circumferential upper point of the line data (D1-D2, D2-D3 ), to determine the type of the building .

FIG. 5A is a diagram showing a specific example of building data (line data) before being converted into polygons created based on the above-mentioned public survey work regulations of the Ministry of Construction, and FIG. 5B.
FIG. 6 is a diagram showing building data (polygon data) after the building data (line data) shown in FIG.

As shown in FIG. 5 (a), in the building data (line data) before being converted into polygons, different types of lines are used to represent the shape and position of the building.
Among the buildings shown by the thick lines, those adjacent to the buildings shown by the dotted lines are not closed as polygons (polygons). On the other hand, as shown in FIG. 5B, in the building data (polygon data) after being converted into polygons, all buildings are represented by closed lines as polygons (polygons). In the building data (polygon data) shown in FIG. 5B, the type of the building is represented by the type of hatching, and the position of the symbol “記号” located in the building corresponds to the point data (pseudo center of gravity). The position is represented.

As described above, according to the present embodiment, a plurality of line data for each building type classified for each type of building are synthesized, and based on all the synthesized line data, While generating corresponding polygon data, based on a plurality of line data for each building type, point data for determining the type of building is generated for each of the line data. Based on the positional relationship with each point data,
Since the building type information is added to each polygon data, polygon data can be efficiently generated from line data representing the outline of the building while minimizing data loss. This makes it possible to effectively utilize polygon data having a much higher information amount and information providing ability than line data as building data used in the geographic information system. Note that, specifically, in the case of Nishinomiya City, where there are about 96,000 buildings, about 1200 buildings fail to be converted into polygons in the above-described conventional polygon processing, but in the present embodiment described above, ,
This can be reduced to 86 buildings, and manual correction of polygon data and the like can be greatly reduced.

In the above-described embodiment, the polygon data generating unit 11 (the line data synthesizing unit 11a and the polygonizing unit 11b), the point data generating unit 12 and the attribute assigning unit 13 are all configured as shown in FIG. It can be realized as a program running on the computer system 30. Here, the computer system 3
0 is the bus 38 and the processor 3 connected to the bus 38
1, a memory 32, a hard disk 33, and a bus 38
Peripheral devices (an input device 34 such as a keyboard and a mouse, an output device 35 such as a display and a printer,
D drive 36 and CD-ROM drive 37). The program as described above is stored in a computer-readable recording medium such as the memory 32, the hard disk 33, the flexible disk 39, and the CD-ROM 40, and is sequentially read out from the processor 31 and executed to execute the program. Such a function or procedure is realized.

[0035]

As described above, according to the present invention, polygon data can be efficiently generated from line data representing the outline of a building while minimizing data loss and the like.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of a building data polygonization system according to the present invention.

FIG. 2 is a diagram showing an example of building data converted into polygons according to the present invention.

FIG. 3 is a diagram showing an example of line data corresponding to the building data shown in FIG. 2;

FIG. 4 is a view showing an example of polygon data generated based on the line data shown in FIG. 3;

FIG. 5 is a diagram showing specific examples of building data (line data) before being polygonized and building data (polygon data) after being polygonized by the present invention.

FIG. 6 is a diagram showing an example of a computer system to which a building data polygonization system according to the present invention is applied.

FIG. 7 is a diagram showing an example of building data which is difficult to make into polygons.

FIG. 8 is a diagram showing another example of building data which is difficult to make into polygons.

[Explanation of symbols]

 10 Building Data Polygonization System 11 Polygon Data Generation Unit 11a Line Data Synthesis Unit 11b Polygonization Unit 12 Point Data Generation Unit 13 Attribute Assignment Unit 21 Building Line Data by Building Type 22 Building Polygon Data 23 Point Data for Building Type Determination 24 Building Type Building polygon data with attributes

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Claims (5)

[Claims] In a building data polygonizing system for generating polygon data based on line data representing the outline of a building, a plurality of line data for each building type classified for each building type are synthesized, and the synthesis is performed. A polygon data generation unit that generates polygon data corresponding to each of the line data based on all the line data obtained, and a point for determining a building type based on the plurality of line data for each building type. A point data generation unit that generates data for each of the line data; and, based on a positional relationship between the generated polygon data and the point data, determining a type of a building corresponding to the polygon data, Based on this determination result,
A building data polygoning system, comprising: an attribute assigning unit that assigns building type information to each of the polygon data. 2. The polygon data generating section generates polygon data corresponding to each line data by connecting start points and end points of all the synthesized line data and intersections of the line data to each other. 2. The building data polygonization system according to claim 1, wherein: 3. The building data polygoning system according to claim 1, wherein said point data generation section generates an internal point and / or a point on a circumference of each of said line data as said each point data. 4. A building data polygonizing method for generating polygon data based on line data representing an outline of a building, wherein a plurality of line data for each building type classified for each type of building are synthesized, and the synthesis is performed. Generating polygon data corresponding to each of the line data based on all of the line data thus obtained; and, based on the plurality of line data for each of the building types, generating point data for determining a type of the building. Generating each line data; determining a type of a building corresponding to each of the polygon data based on a positional relationship between the generated polygon data and the point data; and ,
Adding building type information to each polygon data. 5. A building data polygonizing program for generating polygon data based on line data representing an outline of a building, wherein a plurality of line data for each building type classified for each type of building are synthesized, and the synthesis is performed. A step of generating polygon data corresponding to each of the line data based on all of the line data obtained, and a step of generating point data for determining the type of the building based on the plurality of line data for each of the building types. A procedure for generating each line data, and a type of a building corresponding to each of the polygon data is determined based on a positional relationship between each of the generated polygon data and each of the point data, and based on the determination result, ,
A program for causing a computer to execute the procedure of adding building type information to each polygon data.