JPH06333019A - Map synthesizing method and device - Google Patents

Abstract

PURPOSE:To provide a map synthesizing device which can synthesize a map with the matching properties secured among plural maps by applying the prescribed correction processing in response to the uneven shift in each place. CONSTITUTION:The boundary identification is carried out on a mesh boundary at a preprocessing part 10 for the maps consisting of meshes and given from the 1st and 2nd map data bases 1 and 2. Then a polygon forming part 12 connects together the segments showing the block boundaries and extracts a block area. The result of this extraction is sent to a corresponding relation deciding part 12 of the next stage to secure the correspondence between the areas (between block areas, segments and points) showing the same place in both maps. Then a converting area deciding part 13 divides the places other than the block area into the triangular areas based on each corresponding point. Then a conversion matrix calculating part 14 and a coordinate converting part 15 perform the conversion of coordinates for each corresponding block area and rectangular area having a nearly even shift. Thus plural maps are synthesized together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map synthesizing method and apparatus for synthesizing a plurality of types of maps (topographic maps) showing the same area to create a new map.

[0002]

2. Description of the Related Art Currently, in Japan, various maps such as national land basic maps, city planning maps, road ledger maps, and private residential maps are issued by the national and local governments.
Since each of these maps is created with a predetermined purpose, it is used properly according to the purpose. In other words, each map is marked with high accuracy in the necessary parts according to the purpose of use, but in other parts it may be slightly less accurate or omitted, so it is used for other purposes. Would be inconvenient for you. That is, for example, since the road ledger map is originally created for the purpose of managing the road, the road is described with high accuracy, but there is only a part of the house information. On the other hand, in the case of city planning maps and housing maps, the accuracy of information about houses is high, but the accuracy of the shapes of roads (including block lines) is low.

[0003]

By combining a plurality of these maps and managing them collectively, a map that can meet a wide range of requirements can be obtained and, for example, certain data (new roads, house shapes, It is said that there is no need to do it for each of the corresponding multiple maps even when modifying the data of residents, etc., and it is possible to revise the map with one modification work and there is no difference in version between maps. It can exert excellent effects.

However, as described above, each map has high-precision data and a part that does not, and in view of the surveying method and the time of preparation, each map is simply made to have the same scale. If you try to combine them, the house may get out of the block line.

Therefore, it is necessary to perform a predetermined correction when synthesizing, but the manual correction requires a lot of time and labor because the work is complicated and the amount of the map becomes enormous. In addition, considering automatic correction using a computer, mechanical parallel movement cannot be performed simply because the displacement is different and the amount of displacement is different depending on the location.

The present invention has been made in view of the above background, and an object of the present invention is to maintain the consistency of a plurality of maps by performing a predetermined correction process corresponding to a non-uniform shift depending on a place. A map synthesizing method and device that can be synthesized while being provided.

[0007]

In order to achieve the above-mentioned object, in the map synthesizing method according to the present invention, a line segment indicating at least a boundary of a block is provided for each of a plurality of given maps showing the same region. Blocks are extracted by connecting and polygonizing the block areas, and the corresponding block areas in the plurality of maps are detected, and the corresponding relations of the representative points such as the start point and the end point of each line segment forming the correlated block areas are determined. Obtained, and then divide at least the area other than the block area into small areas based on each of the associated representative points, the corresponding small areas, and the predetermined area in the area in units of the block area The coordinates of the map data are converted and combined.

Further, as a map synthesizing device for implementing the above-mentioned method, a means for extracting at least a block area by connecting at least line segments showing boundaries of blocks to a plurality of given maps to form polygons. , Means for associating each part showing the same location in the plurality of maps with the output of the means for extracting the block area, and a predetermined location of each map by receiving the output of the means for associating A means for dividing into small areas which are conversion units, means for calculating a conversion coefficient necessary for coordinate conversion for each corresponding divided small area and / or for each block area, and the calculated conversion coefficient And a means for synthesizing the plurality of maps by performing coordinate conversion for each small area and each block area.

[0009]

[Function] A plurality of maps in which the deviation direction and the deviation amount are locally uneven are polygonized to extract the block area, and corresponding points such as the start point and the end point of each line segment (the same point in a plurality of map shapes Location) is detected. Then, it is divided into small areas, such as a triangular shape, based on the corresponding points. Then, coordinate conversion is performed for each of the divided small areas or for each of the previously extracted block areas. Then, even if the direction of displacement and the distance are non-uniform in the entire drawing, the direction of displacement and the amount of displacement are uniform or non-uniform when viewed in units of small regions divided in this way. Is reduced. Therefore, coordinate conversion can be performed by simple parallel movement, rotation, and enlargement / reduction. Then, by performing the coordinate conversion for each area, the coordinate conversion of the entire maps can be automatically performed mechanically.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the map synthesizing method and apparatus according to the present invention will be described in detail below with reference to the accompanying drawings.
In this example, a first map having high accuracy for road data such as a road ledger map, and a second map in which various facility data such as house data, power transmission lines, service lines, etc. are described in detail.
Combined with the map, more specifically, on the topographic map composed of the road data (including the block line data) of the first map, the second
A map synthesizing device for synthesizing house data and facility data in which a map is described is shown in FIG. 1 as a schematic configuration of one embodiment thereof.

That is, the first map database 1 and the second map database 2 in which various data on both maps are stored are connected to the map synthesizing device 3, and the predetermined data stored in both map databases 1 and 2 are connected. The map composition device 3 outputs and combines the results, stores the combined result in the combined map database 4, and plots the result on the output device 5 as necessary.

The data stored in the map databases 1 and 2 are, for example, a block line indicating the boundary of a block, a road line indicating the boundary of a road (in many cases, the coordinates of the block line coincide with each other), and There are various line segments such as house lines showing the outline, character information such as building names and names of residents of houses, and data on various facilities (electric poles, electric wires, service lines, manholes, etc.). Then, when actually stored in the database, in the case of a line segment, the coordinates of the start and end points of the line segment and the layer information (block line, road line, house line ...) Meaning the line segment are stored. In the case of character information, the character code and display position coordinates are stored as a pair, and in the case of various types of equipment, the type and arrangement position coordinate are stored as a pair. Then, the respective data are stored in a state of being appropriately divided into groups or layers.

As described above, the first map database 1 stores a map in which, among the above-mentioned data, particularly the data relating to the block line and the road line are created with high accuracy, while the house line, character information, and equipment are stored. The data regarding the above is stored with some or all omitted. The house line, character information, and equipment data are stored in detail in the second map database 2, while the accuracy of the coordinate data of the block lines and road lines stored in the database 2 is the first map. It is lower than that of database 1 (accurate for layer information).

Explaining the synthesizing device 3 according to the present invention, first, the data given respectively from the map databases 1 and 2 are input to the pre-processing section 10, and the identification processing is performed there. That is, both map databases 1 and 2 are stored in a state of being divided into predetermined regions, that is, in mesh units. Then, in the synthesis process in this example, both maps are compared in a mesh unit and a predetermined process is performed. However, if the process is performed in a mesh unit, each line segment is cut at the boundary of the mesh.
That is, as shown in FIG. 2A, there are eight meshes M1 to M8 around the mesh M0 to be processed. The central mesh M0 to be processed includes a line segment L0 having a start point s and an end point e in the mesh, but in many cases, the line segments L1, L2, ...
At least one of the start point and the end point is a mesh M
Some are located on the boundary lines K1 to K4 of 0. Then, it is unclear whether the line segment happens to end on the boundary line or continues to another adjacent mesh side. Therefore, the pre-processing unit 10 is used to refer to the information about the adjacent meshes M1 to M8 to search for the same figure (line segment) and perform boundary identification processing for forming one continuous line segment.

The specific processing procedure in the preprocessing unit 10 is as follows. (1) That is, first, data of all line segments having a start point or an end point on one boundary line of the mesh being processed is listed as an identification candidate. Thus, for example, when focusing on the boundary line K1 on the left side of the mesh M0 in FIG. 2A, there are three points P1 to P3 on the boundary line, so that the corresponding line segments L1 to L3 are the identification candidates. Listed. Similarly, on the right boundary line K3, four line segments L4 to
L7 (points P4 to P7) is listed as an identification candidate.

(2) Next, with respect to the boundary line on the adjacent mesh side, the identification candidates are listed in the same manner as in (1) above. As a result, on the side of the mesh M8 adjacent to the boundary line K1, the two line segments L2 ′ and L3 ′ (points P2 ′,
P3 ') is listed. Further, since a predetermined margin is provided at both ends of the boundary line, the line segment L1 ′ (point P1 ′) is listed up on the side of the mesh M7 that is diagonally lower left. Similarly, also on the boundary line K3 side, line segments L4 'to L6'
(Points P4 'to P6') are listed.

(3) Next, for one identification candidate, among the identification candidates of the adjacent mesh, the distance on the boundary line is short, and it is in the same layer and has not already been identified by another identification candidate. And identify it as an identification partner. Thus, for example, on the boundary line K1 side, L1 and L1 ', L2 and L2', and L3 and L3 'are identification partners. Similarly, on the side of the boundary line K3, the line segment L4 is L4 '.
Is the identification partner. Focusing on the line segment L5, the line segment L6 'is the closest on the boundary line K3, but the line segment L5 is
Layer 5 is a block line, whereas layer L6 'is different depending on the equipment, so it cannot be an identification partner. Therefore, the line segment L5 ′ that is the next closest and is not another identification partner becomes the identification partner of the line segment L5. Similarly, the identification partner of the line segment L6 is the line segment L6 '. Further, since there is no identification candidate that is close to the line segment L7 and is not another identification partner,
It is determined that there is no identification partner of the line segment L7.

(4) The coordinates on the boundary line of the identification partner are compared, and if they match (for example, line segments L2 and L2 '),
Connect as it is and extend the line segment L2 being processed to L2 ',
Update the coordinates of the start and end points. That is, the initial line segment L
The coordinates of the start point and the end point that specify 2 are s2 and P2, respectively, but are updated to s2 and e2. On the other hand, the coordinates on the boundary line of the identification partner are compared, and if they do not match (for example, the line segments L5 and L5 ′), the midpoints of the two on the boundary line are obtained,
The coordinates of the base line segment are updated assuming that they are connected at this midpoint.

As a result of the above processing, FIG.
The data relating to the mesh M0 shown in (A) is, for example, as shown in (B) of FIG. The result is sent to the polygon processing unit 11 in the next stage. The polygonization processing unit 11 is for determining a small area when coordinate conversion is performed to finally combine two maps. Graphic composition (polygonization) is performed so that one block area is represented by one graphic element (polygonal closed space). Then, specifically, the processing is performed according to the flowchart shown in FIG.

That is, first, when one line segment data to be polygonized is selected, it is determined whether or not there is another line segment connected to the end point thereof (S101, 1).
02). If there is one line segment to be connected, the line segment is connected to store the data, and step 1
Returning to 01, processing is performed on the connected line segment (S1).
03, 105). On the other hand, if there is a plurality of line segments to be connected in the judgment of step 103, the one with the smaller clockwise angle is selected (S104). Therefore, for example, in FIG.
In the case as shown in (A), L9 having a small angle is selected.

When there is no line segment to be connected, the distance between the start point s and the end point e of a series of continuous line segments is a certain distance or less ((B) in the same figure), and moreover, the polygon area (each line segment). Is obtained as a vector and the outer product thereof is obtained) is positive ((C) in the figure), the polygon is registered as being correctly created (S106, 107). That is, in this example, when there are a plurality of candidates in step 104, the one having a small angle in the clockwise direction is selected. Therefore, for example, as shown in the left side of FIG. Since the line segment H (the place that should have been determined to be inside the road area) of the sidewalk is judged as the block line, only the part that follows the counterclockwise direction (on the right side in the figure) is polygonal. I try to leave. On the other hand, if the polygon cannot be correctly formed, the process returns to step 101. Then, the polygonization process is performed for all line segments. Then, the processing result is sent to the correspondence determination unit 12 in the next stage. It should be noted that the processes in the identification processing unit 10 and the polygonization processing unit 11 are independently performed for each map.

The correspondence determining unit 12 compares the coordinates of the start point / end point of the line segment forming the first map and each break point in the case of being polygonized with that of the second map to make correspondence (identical). It detects points, line segments, and planes (block areas (polygons) that seem to represent points). As a result, the target for coordinate conversion during map synthesis is specified. And specifically, it is as follows. First, there are the following four basic principles.

Correspondence by point features The closest points (Xi, Yi), (xj, y) between the two maps.
Corresponding points are those where the distance between j) is within the allowable value ε1.

[0024]

## EQU1 ## {(Xi-xj) ² + (Yi-yj) ² } ^1/2 <ε1 Correlation by line feature a) Condition of line segment center position The coordinates of the line segment center position are compared and 2 The distance between two points (Xci, Yci) and (xcj, ycj) between two maps is an allowable value ε2.
Corresponding line candidates are those within the range. However, since the coordinate data relating to the line segment only has the coordinates of the start point and the end point, the center position coordinates are calculated in advance from the both start point / end point coordinate data and then compared.

[0025]

[Formula 2] {(Xci-xcj) ² + (Yci-ycj) ² } ^1/2 <ε2 b) Line segment length conditions The lengths Li and lj of each line segment on each map are calculated and the relative values are obtained. Corresponding line candidates are those with an error within the allowable value ε3.

(Li-lj) / Li <[epsilon] 3 c) Condition of Layer Information of Line Segments The layer information attached to each line segment is the same as the corresponding line candidate.

Correspondence by surface features a) Condition of barycentric position of surface (polygon) Coordinates of barycentric position of surface are calculated, and two points (X
gi, Ygi) and (xgj, ygj) are within the allowable value ε4 as corresponding surface candidates.

[0028]

## EQU3 ## {(Xgi-xgj) ² + (Ygi-ygj) ² } ^1/2 <ε4 where xg = 1 / 6AΣ (yi-yi-1) {(xi + xi-1)
²⁻ xi xi−1} yg = 1 / 6AΣ (xi −xi−1) {(yi + yi−1)
²⁻ yi yi−1} A is the condition of the perimeter of half of the absolute value of Σ (xi + 1 yi −xi yi + 1) b) The perimeters Li and lj of the surfaces on each map are calculated as Corresponding surface candidates are those whose relative error is within the allowable value ε5.

(Li-lj) / Li <ε5 c) Area condition of surface Areas Ai and aj of each surface on the map are obtained, and those having relative error within the allowable value ε6 are regarded as corresponding surface candidates.

(Ai-aj) / Ai <ε6 where Ai is the layer information condition of the surface information of half of the absolute value of Σ (xi + 1yi-xiyi + 1) Layer information attached to each surface Are the same as the corresponding surface candidates.

Correspondence by Topological Features a) Connection Relationship with Adjacent Graphic If there are already associated graphics A and a, B and b that are graphically connected to them are considered as corresponding surface candidates.
As a result, as shown in FIG. 5, since part of the figure b happens to be erased, even if B is a surface and b is a different category such as a line, it can be correctly associated.

(B) Positional relationship between surrounding figures C If there are already associated figures A and a, then C and c in the vicinity of these figures are set as corresponding surface candidates. This allows
For example, as shown in FIG. 5, even if the areas of the surface C and the surface c are greatly different and it is determined that there is no correspondence in the above-described correspondence between the surfaces, they can be correctly matched.

Then, based on the above-mentioned basic principle, the correspondence determining unit 12 associates surfaces and other positions between the maps according to the flowchart shown in FIG.
That is, first, one map, for example, one surface on the first map is selected, and the other map (second map) corresponding thereto is selected.
The corresponding surface candidates above are searched based on the above rules (S201, 202).

When there is only one corresponding surface candidate, the corresponding surface candidate is determined as the corresponding surface. On the other hand, when there are a plurality of corresponding surface candidates, an evaluation value E is obtained for each surface candidate based on the following evaluation formula, and the surface having the highest evaluation value is determined as the corresponding surface. (S203-205).

E = Σfi wi Here, fi is the feature quantity of the surface, and is a) to d) of the above “correspondence by surface characteristics” (actually, if the layer information is different, it will not be a corresponding surface candidate, so a). ~ Ha)) each value.
The smaller each value is, the higher the probability of the corresponding surface is.
The smaller the calculated numerical value, the higher the evaluation value. Further, wi is a weight, which is used to lightly weight each condition, and is set as appropriate.

However, in this example, when the evaluation value of the second highest evaluated surface is close to the maximum value, the reliability R
When the allowable range ε6 is not satisfied, it is determined that there is no corresponding surface and the processing is performed. This reduces the probability of misjudgment.

R = (1−Emax−1 / Emax) <ε6 By the processing of step 202, the corresponding surface candidate is 1
Even if neither is extracted, the process proceeds to step 205 in the branch determination of step 203. However, in the case concerned and when it is determined that there is no corresponding surface despite the plurality of samples being extracted as described above, the above-mentioned is performed. Search for "correspondence by topological features" of, and if found, use it as the corresponding surface,
If there is still no, it is determined that there is no corresponding aspect. The above processing is performed in step 205.

If the corresponding surface for the surface selected in step 201 is determined in this way (including "no corresponding surface"), it is judged whether or not there is an unprocessed surface on one of the maps, and if there is, it is determined. Returns to step 201 and repeats the above processing (S206). As a result, all the faces on one map are associated with each other.

Next, the corresponding line is determined for the line segment by performing the same process as the process for the above-mentioned line segment on one map (that is not polygonized) ( S207-212). In this way, when the surfaces (polygons) and the line segments are associated with each other, each of the points of the corresponding surface and the corresponding line segments have each other according to the above-mentioned "correlation by point features" criterion. The points are associated with each other, and the process ends (S213). Then, the processing result is sent to the conversion area determination unit 13 in the next stage.

The conversion area determination unit 13 determines a small area for coordinate conversion. In this example, the inside of the polygon is converted, that is, the area of the block is subjected to the coordinates conversion and the outside of the polygon is converted. That is, since the road area is divided into triangles and each divided triangle is converted, the determination unit 13 obtains a triangle area having the corresponding points obtained in the preceding stage as vertices. .

More specifically, first, as shown in FIG. 7A, corresponding points (each vertex forming a polygon) near the boundary (double line) K of the mesh to be processed are connected and divided. A boundary line K'of the power region is obtained. Then, the road area D in the mesh and the road area D ′ up to the newly formed boundary line K ′ are subject to triangle division.

Next, the boundary line is connected to the internal points, and the region is divided so that the shape is as close to an equilateral triangle as possible. That is, first, a search is made for one that includes the sides that form the boundary and can generate a triangle. The area A of the triangle that can be generated
And the ratio R of the square of the longest side L (R = A / L ² ) is obtained. Note that the larger this R is, the closer it is to a regular triangle. Similarly, the ratio Rs for the triangle generated adjacent to this triangle is also obtained. Then, the calculated R and Rs are substituted into the following equation to obtain the evaluation value β. The smaller the evaluation value β, the closer two adjacent triangles are to an equilateral triangle.

Β = (Rs −1) ² + (R−1) ² Then, the evaluation value β is calculated for all sides of the boundary line, and a triangle is generated on the side where β is the minimum. When the sides of the triangle are determined in this way, the above-described processing is performed with the side of the determined sides located at the boundary with the undivided region as a new boundary line. After that, the road area can be divided into triangular areas by repeatedly performing such processing.

As an example, in the case of FIG. 7 (A), if one boundary line k ′ is focused as shown in FIG. 7 (B), the triangle having the side as the edge is opr and oqr. There are two types, but if adjacent triangles are considered and substituted into the above formula, the triangle opr partitioned by the line segment pr is closer to an equilateral triangle. Therefore, the triangle opr and the triangle rpq are determined, and the line segment pq is generated as a new boundary line, and a triangle whose side includes the line segment pq is generated. By sequentially dividing the area in this manner, the road area can be divided into a large number of triangular small areas as shown in FIG.

This area division is performed on one map (in this example, the accurate first map of the road data), and on the second map side, the area on the first map side according to the corresponding point obtained above. Reflect the split. Then, when all area divisions have been performed in this way, the result is sent to the conversion matrix calculation unit 14 in the next stage.

The conversion matrix calculation unit 14 obtains a conversion matrix for coordinate conversion of the graphic information on the second map side to the first map side based on the divided areas. Specifically, the conversion matrix is as follows. Ask for.

That is, in this example, since the coordinate transformation is performed by using the affine transformation shown by the following equation, the transformation matrix calculating unit 14 requires the coefficients a, b, c and x0 required for the transformation.
, Y0 (matrix) will be obtained.

[0048]

[Equation 4] Then, as shown in FIG. 8, since the corresponding triangular regions are known, three corresponding points (coordinate values) are known. Therefore, the transformation matrix can be obtained by substituting the respective coordinate values into the following equation.

[0049]

[Equation 5] As a result, the transformation matrix of the area divided into all the triangles is calculated, but for polygons of the quadrilateral or larger of the polygons in the block area (the triangle is obtained by the above formula), the corresponding points are 4 or more. Since there are more equations than unknowns, the solution cannot be uniquely determined. Therefore, the coefficient is obtained using the least squares method. That is, the coefficient matrix of the above simultaneous equations is obtained by partially differentiating the evaluation function as shown in the following equation with respect to each unknown.

[0050]

[Equation 6] Then, the coordinate matrix and the coordinate data of the areas having a pair of corresponding relations are sent to the coordinate conversion unit 15 in the next stage, where the map for coordinate conversion for each area is synthesized. More specifically, by matching the area of the second map with the corresponding area of the first map that has been subjected to coordinate conversion, the houses, facilities, etc. on the second map are arranged at predetermined positions on the first map.

That is, a graphic (house, equipment) included in the area is searched. Then, for example, as shown in FIG. 9 (A), when there are facilities such as a house line I and a drop line H located in a polygon (block area) on the second map,
Coordinate conversion is performed using the conversion matrix for the polygon to combine the polygons with the first map (FIG. 7B).

Similarly, as shown in FIG.
When the equipment H exists in a triangular area having a road area on the map, coordinate conversion is performed using a conversion matrix for the triangular area to synthesize the map on the first map (FIG. 2B). ).

In the case of equipment within the triangular area,
As shown in FIG. 11, such facilities H1 and H2 may exist over a plurality of triangular regions R1 and R2.
In such a case, the conversion matrix of the area may be used to convert the portion included in each area. However, in this example, any one of them is used so that the shape after conversion becomes more natural. The conversion is performed using the conversion matrix of one region. As a method of determining such one area, for example, the area to which the largest number belongs or the area having the position of the center of gravity (or center) can be extracted. In the illustrated example, the two facilities H1, H
Both 2 will be converted based on the region R2.

Next, one embodiment of the map synthesizing method according to the present invention will be described using the above-mentioned embodiment. First, the data for each map is read from the first and second map databases 1 and 2. Then, the preprocessing unit 10 connects adjacent meshes on the boundary line of the mesh of each map, that is, performs boundary identification. In this example, since each map is divided into multiple meshes for data storage,
Boundary identification is performed by the preprocessing unit 10.
When one map is formed by one sheet, such preprocessing is unnecessary.

Next, the polygonization unit 11 connects the line segments. Thereby, a closed space is formed and a block area is extracted. Then, the correspondence determination unit 12 obtains a block area indicating the same area on both maps, and further,
Other corresponding line segments are also extracted. Then, each point (vertex) of the corresponding block area and the corresponding points at the start and end points of the corresponding line segment are also obtained.

Then, the conversion area determining unit 13 divides the area outside the block area, that is, the area of the road area into triangular small areas. At this time, each vertex of the divided small area is
The above-mentioned corresponding points are obtained, and each triangle is divided so that it is as close to an equilateral triangle as possible.

Then, a conversion matrix for performing coordinate conversion between the triangles (small areas) divided by the conversion matrix calculation unit 14 and between the block areas is obtained, and the coordinates of the next stage are calculated based on the obtained conversion matrix. The conversion unit 15 performs affine conversion and coordinate conversion. More specifically, the conversion target objects such as house lines and facilities existing in the area of one map (on the side where the coordinate conversion is performed) are subjected to coordinate conversion and are combined on the other map. Then, by performing coordinate conversion for each area in this way, the coordinate conversion of the entire map is performed, and a highly accurate map that combines high-precision display parts and a user-friendly map that meets all requirements is created. It is automatically generated.

In the above embodiment, the block area is made into polygons and the area is converted in units of polygons. However, the present invention is not limited to this, and the block area is also divided into triangular areas. However, coordinate conversion may be performed. In such a case, for example, the accuracy of the map is not so high, and it is particularly effective when the shapes of the block areas in the two maps are significantly different. Also,
The shape of division is not necessarily limited to a triangle.

In the case of synthesizing three or more maps, first, two predetermined maps are synthesized, and the synthesized map can be synthesized with another map. .

[0060]

As described above, in the map synthesizing method and apparatus according to the present invention, a plurality of maps describing the same area are divided into small areas while associating each part with each other, and the coordinates of each divided small area are coordinated. Since the conversion is performed, the direction and amount of the positional deviation are substantially the same in the range of such a small area, so that a simple mechanical change can be performed. Accordingly, by performing coordinate conversion for all the small areas, it is possible to automatically combine a plurality of maps having complicated displacement directions and distances as a whole. As a result, it is possible to synthesize and form a more accurate map while making the most of the advantages of multiple maps, and to easily perform subsequent data revision work.

[Brief description of drawings]

FIG. 1 is a block diagram showing a preferred embodiment of a map synthesizing apparatus according to the present invention.

FIG. 2 is a diagram illustrating an operation of a preprocessing unit.

FIG. 3 is a flowchart illustrating the operation of a polygonization unit.

FIG. 4 is a diagram illustrating an operation of a polygonization unit.

FIG. 5 is a diagram illustrating an operation of a correspondence relationship determining unit.

FIG. 6 is a flowchart illustrating the operation of a correspondence relationship determining unit.

FIG. 7 is a diagram illustrating an operation of a conversion area determining unit.

FIG. 8 is a diagram illustrating an operation of a conversion matrix calculation unit.

FIG. 9 is a diagram illustrating an operation of a coordinate conversion unit.

FIG. 10 is a diagram illustrating an operation of a coordinate conversion unit.

FIG. 11 is a diagram illustrating an operation of a coordinate conversion unit.

[Explanation of Codes] 1 First map database 2 Second map database 3 Map synthesizing device 4 Synthetic map database 5 Output device 10 Pre-processing unit 11 Polygonizing unit 12 Correspondence determining unit 13 Transformation area determining unit 14 Transformation matrix calculating unit 15 Coordinate conversion unit

Claims (5)

[Claims] 1. A block area is extracted by connecting at least a line segment indicating a boundary of a block to each of a plurality of given maps showing the same area to form a polygon and extracting a block area, and corresponding block areas in the plurality of maps. Is detected,
The correspondence between the representative points such as the start point and the end point of each line segment that constitutes the associated block area is obtained, and then at least the area other than the block area is set as a small area based on the associated representative points. A map synthesizing method of dividing and performing coordinate transformation of predetermined map data in the area in units of the corresponding small areas and the block areas. 2. The map synthesizing method according to claim 1, wherein the corresponding block area is further divided into small areas. 3. The map synthesizing method according to claim 1, wherein the small area has a triangular shape. 4. When there is a conversion object such as a line segment existing across a plurality of adjacent small areas and / or block areas when the coordinate conversion is performed in units of the small areas and / or the block areas, A map synthesizing method in which coordinate conversion is performed according to any one of the conversion rules for a small area or a block area. 5. A means for extracting a block area by connecting at least line segments showing boundaries of the block to a given plurality of maps and converting the polygon into polygons, and receiving the outputs of the means for extracting the block area. Means for associating each part showing the same location in the plurality of maps, means for receiving the output of the means for associating, and dividing the respective maps into small areas as conversion units, Means for calculating a conversion coefficient required for coordinate conversion for each small area and / or for each block area; and coordinate conversion for each small area, block area based on the calculated conversion coefficient. A map synthesizing device having means for synthesizing.