JP3373145B2 - Contour line connection method and recording medium - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contour line connecting method for connecting, by computer processing, locations where contour lines are divided on a map drawing in a computer system for handling map drawings.

[0002]

2. Description of the Related Art In a computer system for handling map drawings currently in practical use, a paper map is used to draw various figures such as house frames, building names, roads, and contour lines that compose the map. A method of inputting as image data by an image scanner or the like and vectorizing based on the data is often adopted. In this vectorization, if there is a division due to blurring of contour lines or the like seen in the image, the drawing result is inevitable as shown in FIG.
It is often a contour line where 0 exists. Therefore, in order to obtain a contour line having no broken points, it is necessary to connect the broken points when vectorizing. But,
There are various shapes of contour lines, and there are various ways of dividing them. From the human eye's point of view, it is often difficult for a computer to judge a path for interpolating a divided portion even if it is obvious.

Conventionally, as a technique for connecting such divided contour lines, as disclosed in Japanese Unexamined Patent Publication No. 146681/1990, "Contour line extraction method", a predetermined point is defined from the end points of the divided contour lines. It is known that contour vector graphics within a range are connected at the shortest distance.

[0004]

However, in the above prior art, when there is a dividing point, one end of the divided contour line is used as the starting point and the contour line with the shortest distance within a predetermined range from the starting point is formed. To connect, eg FIG.
As shown in (a), when attempting to connect the divided contour lines L1 and L2, a predetermined range is set like Box1, and within this range, the end points of the contour vector graphic with the shortest distance from the end points of L1 are set. The contour lines L1 and L2, which are detected and are separated by the connecting path connected to the end point, are connected. According to this conventional method, in Box 1, the right end points of routes W2 and L1 connecting the right end point of L1 and the left end point of L2 and L
There is a path W3 connecting the right end points of the paths W1 and L2 connecting to the right end point of 2 and the left end point of L3, and a path W4 connecting the left end point of L2 and the left end point of L3. Among them, L1 and L2 are connected. Since W1 is shorter than W2 for the route, this W1 is selected. As a result, the divided contour lines L1 and L2
However, as shown in FIG. 11 (b), there is a problem in that they are connected via the route W1 and cannot be connected correctly.

An object of the present invention is to provide a contour line connecting method by which an operator can easily and correctly connect divided contour line vector figures.

[0006]

In order to achieve the above object, the present invention connects all of the connecting paths connecting the respective end points of a plurality of contour vector figures designated from the outside among the divided contour lines. Calculate as a route candidate, and do not intersect with existing contour lines from among these connected route candidates,
The shortest route length is determined as a connection route, a new contour vector graphic is generated on the determined connection route, and the divided contour lines are connected.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a system configuration diagram for performing contour line connection processing according to the present invention. In FIG. 1, 110 is a central processing unit (CPU) for connecting contour lines, 120 is a file device for storing a vector graphic such as a map read by an image scanner or the like as a drawing, and 130 is a drawing and a vector graphic on the drawing. Is a display device for displaying, 140 is an instruction device for instructing the divided contour lines to be connected by the operator, 150 is a program memory for storing a program necessary for performing processing in the CPU 110, 160 Is a pointing device for designating a coordinate position and the like on the pointing device 140. The program memory 150 stores a coordinate acquisition unit 151 that acquires the coordinate values of each control point of a vector graphic on the drawing, and a designated contour line connection processing unit 152. The coordinate acquisition unit 151 and the connection processing unit 152 are composed of programs that the CPU 110 can execute.

First, the case where the operator selects two divided contour lines to be connected will be described with reference to the explanatory view of FIG. 2 and the flowchart of FIG. The processing shown in FIG. 3 shows the processing content that the coordinate acquisition unit 151 and the connection processing unit 152 jointly perform.

In the present invention, the operator only specifies the target contour lines and does not indicate which end points of the two contour lines are to be connected. In the example of FIG. 2, L1 and L2 are contour lines designated by the operator. First, candidates for a connecting route between the designated contour lines L1 and L2 are calculated (step 301). In the case of the example in FIG. 2, as the candidate of the connecting path connecting the contour lines L1 and L2, the left end points of the paths W1 and L1 connecting the right end point C3 of L1 and the left end point c4 of L2 and the left end point C4 of L2 are connected. Four paths W3 connecting the right end point C3 of the connecting paths W2 and L1 and the right end point of L2 and the path W4 connecting the left end point of L1 and the right end point of L2 are extracted.

Next, four connection route candidates W1, W2, W
Among 3 and W4, the connecting route candidates that intersect the existing contour lines are excluded from the candidates (step 302). In this step, since W3 and W4 intersect the existing contour line L2 at C1 and C2, respectively, they are excluded from the connecting route candidates. This is because the contour lines do not intersect in the middle because of their own property.

Next, of the remaining connecting route candidates W1 and W2, the one having the shortest route length is determined as the connecting route (step 303). Here, the shorter one of W1 and W2 is
Since it is W1, this W1 is determined as the connection path.

Next, vector graphic data of the determined connecting route W1 is generated, and by this vector graphic data,
The divided route W1 is connected (step 304). As a result, the divided contour lines L1 and L2 in FIG. 2A are connected as shown in FIG. 2B.

As described above, when deciding a route for connecting two contour lines, "a connection route candidate that does not intersect with existing contour lines among the connection route candidates connecting the end points of the divided contour lines is selected. It is possible to rationally connect the divided contour lines by using the method of "extracting and adopting the path with the shortest path length among them as an appropriate connection path". In that case, since the operator only specifies the divided contour lines to be connected, the operation is extremely simple.

Next, a case where the operator selects three or more divided contour lines to be connected will be described. Hereinafter, a case of connecting three contour lines will be described in order to simplify the description.

FIG. 4A shows three contour lines L1, L2 and L3 which are divided. In FIG. 4A, when the operator designates the connection target in the order of L1, L2, and L3 as the connection target, the procedure for connecting the three dividing contour lines into one is as follows. First, L1 and L2 are connected to form CL. That is, the right end points C3 and L of L1
The left end point C4 of 2 is connected to be CL. This state is shown in FIG. In this way, L1 → L designated by the operator
Contour lines are connected in the order of 2 → L3. Therefore, FIG.
In (a), the right end point C3 of L1 and the left end point C6 of L3
The path connecting the and is not adopted as a connection candidate when connecting L1 and L2.

Next, the right end point C5 of CL and the left end point C of L3
6 is connected to form one contour line. With the above, the three dividing contour lines are connected to one. Here, the process of connecting L1 and L2 and the process of connecting CL and L3 follow the process of FIG. 3 described above.

However, the three contour lines L1, L2, L3
5 is in the state as shown in FIG. 5A, the process shown in FIG. In this case, the result of the connection is as shown in FIG. This is L1 and L2
Although the connection route candidate expected when connecting L1 is W2 that connects the right end point C7 of L1 and the left end point C8 of L2,
W1 connecting the right end point C7 of L and the right end point C9 of L2 is W
This is because W1 is eventually adopted because the path length is shorter than 2.

The result as shown in FIG. 5 can be avoided by increasing the number of contour lines to be considered in determining the connection route from two to three. FIG. 6A is a diagram of FIG.
Although the same state as (a) is shown, the comparison route here is a pair of “W1, W4” and a pair of “W2, W3”. That is, W1 is added to the route when connecting L1 and L2
(Route connecting the right end point C7 of L1 and the right end point C9 of L2)
If is selected, the route selected when connecting L2 and L3 is W4 (route connecting the left end point C8 of L2 and the left end point C10 of L3), while the route used when connecting L1 and L2 If W2 (the route connecting the right end point C7 of L1 and the left end point C8 of L2) is selected, the route selected when connecting L2 and L3 is W3 (the right end point C9 of L2 and the left end point C of L3.
10), the pair of “W1, W4” and the pair of “W2, W3” are compared.

The comparison method is to compare the sum of the route lengths of the route pairs and adopt the shorter route pair. In FIG. 6A, the shortest route length is “W2, W
3 ”route pair. By adopting and connecting the route pair of "W2, W3", the connection result is shown in FIG.
Would be rational.

Here, in the example of FIG. 6, the connection candidate route W
All of 1, W2, W3, and W4 did not intersect with the existing contour line, but if this is the state as shown in FIG. 7A, the route W3 intersects with the existing contour line at C1. , The routes to be adopted are a pair of (W1, W4).

As described above, if even one of the routes forming a pair intersects with the existing contour line, the pair is discarded. Therefore, the connection result is as shown in FIG.

Next, the processing of the program for realizing this method will be described with reference to the flowchart of FIG. 8 in FIG.

First, an array of contour lines to be connected is input. The array name L [] (where [] = 1 to Ln) is set, and the number of elements in the array is set to Ln (where Ln ≧ 2) (step 801).

Next, the output data area is initialized (step 802) and 1 is substituted for n (step 803).
Next, (n + 2) is compared with Ln (step 804),
Here, when Ln is larger than “n + 2”, Ln
Compare the contour lines of [n], L [n + 1], and L [n + 2] to obtain L
The route connecting [n] and L [n + 1] is determined (step 805). Next, L [n] and the determined connection path are added to the output data area (step 806), and n is incremented by "1" (step 807).

If (n + 2) is greater than or equal to Ln in step 804, a route connecting L [n] and L [n + 1] is determined (step 808).

The connection path determined to be L [n] and L [n + 1]
Is added to the output data area (step 809). Next, contour lines are defined on the drawing based on the output data (step 810). All contour lines of L [] are deleted (step 811).

Next, the processing of steps 804 to 807 will be specifically described with reference to FIG. FIG. 9 is a diagram showing a specific example of the processing in the case where the operator has designated the four divided contour line vector figures as connection targets. As shown in FIG. 9, first, L1, L2, and L3 are compared, W1 and W2 are determined, and W1 is adopted. Next, L1 and L3, which are the connection results of L1 and L2, are compared, and W1 and W
Determine 2 and adopt W1. Next, L1-3, L4, and L5, which are the connection results of L1 to L3, are compared, and W1 and W2 are compared.
And W1 is adopted. Next, L1-4, which is the result of linking L1 to L4, and L5 are compared, W4 is determined, and W1
To adopt.

In this way, L1 to L5, which have been divided in FIG. 9A, are connected to form one contour line vector figure.

As described above, in the present invention, when determining two routes that connect three contour lines, a route that intersects with existing contour lines is included from among possible pairs of routes. The one with the shortest sum of path lengths is adopted and connected,
If the operator selects four or more separated contour lines to be connected, the first, second and third, then "1
For the 3rd and 2nd connecting line "and the 3rd and 4th, then the" 1st, 2nd and 3rd connecting line "and the 4th and 5th, etc. Determine the connection route by the method, and temporarily determine the two routes that connect the three contour lines, and then use the one of the two routes that connects the youngest contour lines. One route is adopted in the next route determination.

That is, in the comparison of the first, second and third object contours, the route connecting the first and second is determined, and the "first and second connecting lines" and the third and fourth In the comparison, the route connecting the “first and second connecting lines” and the third is determined. In other words, in order to determine the path connecting the two contour lines, the position of the other contour line ahead is also taken into consideration.

By the above method, the connection route can be rationally determined regardless of the number of contour lines to be connected specified by the operator. Depending on how the contour lines are divided, it may result in an unfavorable result if the connecting route is drawn by a straight line, but in such a case, after determining the route by the processing of the present invention described above, The “passing point” may be input.

The program for performing the above-mentioned linking process is recorded on a recording medium such as a CD-ROM and provided to a user of an existing computer system for map processing.
It can be used as a tool for connecting contour lines.

[0033]

As described above, according to the present invention,
It is possible to rationally connect the divided contour lines by performing a simple operation of designating the contour lines to be connected without the operator designating the connection path. Further, since there is no theoretical upper limit on the number of contour lines to be connected, it is possible to specify all the contour lines to be connected in the order of connection. As a result, it is possible to significantly reduce the operator's burden on processing for many contour lines existing on one drawing.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating an embodiment of a system for performing contour line concatenation according to the present invention.

FIG. 2 is an explanatory diagram of a method of connecting two contour lines.

FIG. 3 is a flowchart showing a basic processing procedure of the present invention.

FIG. 4 is an explanatory diagram (part 1) of a method of connecting three contour lines.

FIG. 5 is an explanatory view (No. 2) of the method of connecting three contour lines.

FIG. 6 is an explanatory view (No. 3) of a method of connecting three contour lines.

FIG. 7 is an explanatory view (No. 4) of the method of connecting three contour lines.

FIG. 8 is a flowchart showing a processing procedure of the present invention.

FIG. 9 is an explanatory diagram of a method of connecting four or more contour lines.

FIG. 10 is a diagram showing an example of divided contour lines.

FIG. 11 is an explanatory diagram showing a processing example of a conventional technique.

[Explanation of symbols]

110 ... Central processing unit, 120 ... File unit, 130
... display device, 140 ... instruction device, 150 ... program memory, 151 ... coordinate value acquisition unit, 152 ... contour line connection processing unit.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G06T 1/00-5/50 G06T 9/00-9/40 G06T 11/60-17/50

Claims (6)

(57) [Claims] 1. A method of displaying vectorized map data stored in a drawing file on a display device screen and connecting the divided contour vector graphics displayed on the display device screen by computer processing. Accepts an instruction from a pointing device for a plurality of contour vector graphics to be connected among the divided contour vector graphics on the vectorized map data displayed on the device screen, and each end point of the designated contour vector graphics Acquiring the coordinates of the above from the drawing file and extracting all of the routes connecting the respective end points as the candidate of the connecting route, and from the extracted candidates of the connecting route, without intersecting with the existing contour line vector figure, And the step of determining the path with the shortest path length as a connected path, and a new contour vector figure on the determined connected path. Form, contour connecting method characterized by comprising the step of coupling the shed contour vector graphic. 2. A method for displaying vectorized map data stored in a drawing file on a screen of a display device and connecting the divided contour vector graphics displayed on the screen of the display device by computer processing. From the instructing device, an instruction for a plurality of contour vector graphics to be connected among the divided contour vector graphics on the vectorized map data displayed on the device screen is received, and three contour vector graphics to be connected are instructed. In this case, the first step of acquiring the coordinates of each end point of the designated contour vector graphic from the drawing file and extracting all the paths connecting the end points as connection path candidates, and the extracted connection path from among the candidates, the candidate which intersects the existing contour vector graphic is excluded, the pair of the connecting path candidate from the candidate of the remaining connection channel And a third step of determining the shortest path length of the created pair of connecting path candidates as a connecting path pair, and a new step on the connecting path of the determined connecting path pair. And a fourth step of connecting the divided contour vector figures, and connecting the divided contour vector figures. 3. When, in the first step, four or more contour vector figures to be connected are designated, a fifth step of selecting three contour vector figures in the order of connection, and three selected contour vector figures The first to
After the connection in the fourth step, the connected contour vector figure and the unconnected contour vector figure are selected in the order of connection to make three new sets, and the steps of connecting in the first to fourth steps are repeated. 6. The contour connecting method according to claim 2, further comprising a sixth step of connecting four or more divided contour vector figures. 4. A medium in which a program for displaying vectorized map data stored in a drawing file on a display screen and connecting the divided contour vector graphics displayed on the display screen by computer processing is recorded. The display device screen accepts instructions from the pointing device for a plurality of contour vector graphics to be connected among the divided contour vector graphics on the vectorized map data displayed on the display screen, and the designated contour vectors The process of acquiring the coordinates of each end point of the figure from the drawing file and extracting all the routes that connect each end point as candidates for the connection route, and the existing contour vector graphics from the extracted candidates for the connection route. The process of determining a route that does not intersect and has the shortest route length as a connecting route, and a new contour line map on the determined connecting route. It generates a torque figure, shed computer readable recording medium characterized in that a program for executing a process of connecting the contour vector graphic in a computer is recorded. 5. A medium in which a program for displaying vectorized map data stored in a drawing file on a display device screen and connecting the divided contour line vector graphics displayed on the display device screen by computer processing is recorded. Therefore, from the indicating device, an instruction for a plurality of contour vector graphics to be connected among the divided contour vector graphics on the vectorized map data displayed on the display device screen is received, and the contour vector graphics to be connected are When three instructions are given, the first process of extracting all the routes connecting the endpoints of the designated contour vector graphics as the candidate of the coupling route, and the existing contour lines from the extracted candidates of the coupling route. candidate intersecting the vector graphic is excluded, a second processing for creating a pair of connecting path candidate from the candidate of the rest of the connecting path, creating The third process of determining the shortest path length among the selected pair of connected path candidates as a connected path pair, and generating a new contour vector graphic on the connected path of the determined connected path pair, and dividing it. A computer-readable recording medium having recorded thereon a program for causing a computer to execute a fourth process for connecting the formed contour vector graphics. 6. A fifth process of selecting three contour vector graphics in the order of connection when four or more contour vector graphics to be connected are designated in the first processing, and three selected contour vector graphics The first to
After connecting by the fourth process, the connected contour vector figure and the unconnected contour vector figure are selected in the order of connection to create three new sets, and the steps of connecting by the first to fourth steps are repeated. 6. The computer-readable recording medium according to claim 5, wherein a program for causing a computer to execute a sixth process for connecting four or more divided contour vector graphics is recorded. .