JPH11283004A - Cadaster data management method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cadaster data management method capable of preserving data fetched from a cadaster together with accurate data obtained by actual measurement and reutilizing the accurate measured data connected with map data at any time as needed. SOLUTION: Measurement work is performed first and the measured data are obtained (Step 10). Then, the measured data are fetched to a computer and automatically drawn (Step 11). Then, the raster data of the cadaster are displayed on a computer screen together with the automatically drawn measured data (Step 12), a point on the measured data and the point on the cadaster are matched and directions are matched. Then, an appropriate point is selected on the automatically drawn measured data and moved to the point on the cadaster corresponding to the point (Step 14). Thus, the point on the measured data and the cadaster are made to correspond to each other in the computer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cadastral map data management method for vectorizing raster data taken from a cadastral map and storing the vectorized data together with data obtained by actual surveying.

[0002]

2. Description of the Related Art When a cadastral map is to be made into a database, if the cadastral map is old, the shape and area of an image described therein often do not match actual survey data. In areas where cadastral surveys are progressing, such as in urban areas, there are places where new cadastral maps created after the war have been created, and work to recreate cadastral maps once every few years has already been done is there. However, in areas where urbanization is slow, cadastral surveys have not progressed in many places. It is used as a public map used by government offices and public institutions.

[0003]

By the way, even if an attempt is made to rewrite an old cadastral map in accordance with the latest survey data, there are many difficulties due to the historical background and complicated relations of rights-related interests. . For this reason, while public institutions such as the Ministry of Justice and the tax office recognize that there is a problem in that the accuracy of old cadastral map data is lower than that of actual data, In many cases, various procedures have to be performed based on a cadastral map that has been conventionally used, rather than accurate survey data obtained by surveying. Therefore, for procedures involving legal treatment, the transaction amount and tax amount are determined based on such an old cadastral map.

On the other hand, when performing public works such as road works and water works, accurate survey data is required. Until now, linking and managing such accurately surveyed data with the aforementioned cadastral map has not been carried out except in urban areas where cadastral surveys are underway. Also, the surveying company often asks a surveyor for surveying every time construction is carried out, and there is a problem that repeated work is repeated.

The present invention has been made based on the above circumstances, and stores data taken from a cadastral map together with accurate data obtained by actual surveying, and links it with cadastral map data whenever necessary. It is an object of the present invention to provide a cadastral map data management method that can reuse accurate survey data.

[0006]

According to a first aspect of the present invention, there is provided a cadastral map data management method for achieving the above-mentioned object. For each point, survey data obtained by surveying corresponding to that point is given as related data,
It is characterized in that it is stored together with the vector data.

According to a second aspect of the present invention, in the first aspect of the present invention, only one or both of the vectorized data and the data obtained by the survey are displayed in an overlapping manner. It is characterized by the following. The cadastral map data management method according to the third aspect of the present invention is a method of combining raster data obtained by reading a cadastral map and a figure obtained based on survey data of the land obtained by surveying on a display device. A step of displaying, and relating a predetermined point on the diagram obtained based on the survey data and a point corresponding to the predetermined point on the raster data, to obtain a diagram obtained based on the survey data. Superimposing the raster data on the raster data, vectorizing the raster data, and the survey data corresponding to the point on the vector data obtained by the vectorization step corresponding to the predetermined point, the relational data And storing the data together with the vectorized data.

According to a fourth aspect of the present invention, in the third aspect of the present invention, only one of the vector data vectorized in the vectorization step and a diagram obtained based on the survey data is provided. Alternatively, both are superimposed and displayed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the following, the cadastral map of land used by a public agency such as the Legal Affairs Bureau will be described as an example of the cadastral map data. FIG. 1 is a diagram illustrating the relationship between a cadastral map of a certain land displayed on the screen and data obtained by actual surveying. In FIG.
_{For 1} , S ₂ , S ₃ and S ₄ , a cadastral map and data obtained by actual survey are shown. An image is defined by a plurality of points P _i (i = 1, 2, 3,...) Around the image and a straight line connecting these adjacent points. In the case of the Cima format that is used as a standard in the field of surveying, the data of each point P _i includes a point number, a point name,
z) are given as point coordinates, and the surface (ie, image) data is given as a surface number, an image name, and constituent points constituting these images.

In FIG. 1, solid lines and dots indicated by circles indicate the whole or a part of the original cadastral map read by a scanner or the like, and dotted lines and points indicated by triangles are obtained by actual surveying at the same place. 2 shows a survey map drawn based on the obtained values. As shown in the figure, since the old cadastral map is often inaccurate, the cadastral map (solid line) and the drawing based on the actual survey data (dotted line) generally do not match.

As described above, it is difficult to switch an old cadastral map to a map based on newly re-measured data. However, accurate survey data such as water supply works and road widening works are difficult. If you need to use the old old cadastral map, you cannot use it. For this reason, it is often necessary to use the old cadastral map and the latest survey data interchangeably as necessary, and there is a demand for storing accurate survey data together with the old cadastral map. . In particular, departments that perform urban planning, land readjustment, water supply work, road widening work, etc. have strong demands.

Generally, an old cadastral map is a drawing drawn on paper, and the volume thereof is enormous, which is inconvenient for storage and handling. For this reason, work is underway to capture a cadastral map with a scanner or the like, convert a vast amount of paper data into digital image data, and display the digital image data on a computer screen such as a CRT or liquid crystal display. However, such image data is originally based on a cadastral map having a problem with accuracy, and often does not match actual survey data. However, as described above, such cadastral maps are often used for legal handling. Therefore, the data is recorded on a high-density recording medium, and the cadastral map is displayed on a computer screen as necessary. Is useful if it can be displayed. On the other hand, actually measured data may be required in some cases, and it is desired to link both to form a database.

In the present embodiment, raster data read by a scanner or the like is vectorized, and the vectorized data is used as data for screen display. By rasterizing raster data, which is general image data, as described above, not only the data amount can be reduced, but also it is possible to easily move points and other various operations on the screen. . On the other hand, with respect to this vectorized data (data for screen display), data obtained by actual surveying is given as attribute data, the two are linked, and both are stored together. Attribute data is point data or line data of vector data, or related data for both data,
Link data.

FIG. 2 is a diagram for explaining the correspondence between a cadastral map and a map based on actual survey data according to the present embodiment.
FIG. 2 is a diagram showing both a cadastral map of a certain plot and a diagram based on survey data. 2, a solid line shows a cadastral this plots were, vertex coordinates are represented with lower case x, using y (x _1, y ₁₎ and the like. The image in the cadastral map may be raster data just read by a scanner, or may be digital data already vectorized. On the other hand, in FIG. 2, the dotted line indicates data obtained by actual surveying on the same ground as indicated by the solid line, and the coordinates of the vertices are capital letters X,
It is represented as (X ₁ , Y ₁ ) using Y.

As shown in FIG. 2, generally, a dotted line and a solid line
I will not do it. Therefore, the solid line diagram based on the cadastral map and the actual
Draw a dotted line based on the survey data at a specific point
(X ₁, Y₁)) And a specific side (here, a point (x
₁, Y₁) And point (x_Two, Y_Two)
Let it match. To match a specific point, it is
Is necessary to take correspondence between other points
Yes, specifically the most distinctive feature of a given picture, such as a corner
Is set as such a reference point. Also, a specific side
To match each other is to determine the direction of the two figures
It is necessary.

The corresponding vertices of the image represented by the solid line and the image represented by the dotted line at that time, ie,
(X ₂ , y ₂ ) and (X ₂ , Y ₂ ), (x ₃ , y ₃ ) and (X ₃ , Y ₃ ), (x ₄ , y ₄ ) and (X ₄ , Y ₄ ) , And each point (x ₁ , y
_{1), (x 2, y} 2), (x 3, y 3), (x 4,
y ₄ ), the data (X ₁ , Y ₁ ), (X ₂ , Y ₂ ), (X ₃ ,
Y ₃ ) and (X ₄ , Y ₄ ) are given as attribute data and stored together.

In this way, when the solid-line cadastral map is displayed, if necessary, accurate data of each point is called up and used, for example, for water supply work, road widening work, etc. It can be used for various applications that require accurate survey data. In addition, in areas where the survey has been completed by the cadastral survey, the cadastral map and this survey data should be stored together and the storage location should be clarified.
Reuse becomes possible. Therefore, it is possible to save the trouble of separately performing surveying work every time accurate surveying data is required, and also to reduce the surveying cost.

FIG. 3 is a flowchart showing a procedure for linking and storing cadastral map data and survey data according to the method of the present embodiment. In the example of FIG. 3, first, the surveying operation is performed first (Step 10), and surveying data is acquired. The survey data obtained in this way is taken into a computer and automatically plotted (Step 11). The survey data drawn and displayed is vector data. In the example of FIG. 2, the dotted line corresponds to this.

Next, the raster data of the cadastral map read using a scanner or the like is displayed on the computer screen together with the survey data that has been automatically plotted (Step 12).
The cadastral map data corresponds to the solid line in the case of FIG. Then, an appropriate point (reference point) of the survey data that is automatically plotted is matched with a corresponding point on the cadastral map and the directions of both (Step 13).

Next, in order to vectorize the cadastral map, a work of superimposing the figure of the survey data on the cadastral map is performed. An appropriate number of points α _i other than the reference points are selected on the automatically plotted survey data and moved to a point β _i on the cadastral map corresponding to the point α _i (Step 14). This operation moves the mouse pointer over the survey data on the screen,
Clicking here selects that point α _i . Then, the point α _i is dragged to the corresponding point β _i on the cadastral map, and the drag is released at the point β _i . By detecting the operation of superimposing the points on the survey data chart on the points on the cadastral map in this way, the points on the survey data chart and the points on the cadastral map are related inside the computer. Are associated. By doing so, the coordinate value of each vertex is obtained, so that it is possible to easily calculate the area of the image.

Further, if necessary, a cadastral map is output by a plotter or the like (Step 15), or the survey data provided as attribute data is converted into a Cima format which is a standard format in the field of survey. And output (Step 16). The drawing output by the plotter can be used as the cadastral map described first. Of course, if necessary, only the survey data or the cadastral map data and the survey data can be output together. Is also possible.

By doing so, the cadastral map can be displayed using the vector data created based on the original cadastral map. You can also switch to Furthermore, it is also possible to display both of them together and visually recognize how different the two are. In this case, when the difference between the two exceeds a predetermined threshold value, a highlight may be displayed.

FIG. 4 is a diagram showing a method of linking and storing cadastral map data and survey data according to the method of the present embodiment.
6 is a flowchart showing a procedure different from that of FIG. In the example of FIG. 4, first, the existing cadastral map is read by a scanner or the like (Step 20), and the read raster data is displayed on the screen of the CAD software (Step 21). And
This raster data is converted into vector data (Step 2)
2). In the example of FIG. 2, the line shown by the solid line corresponds to the line of the cadastral map converted into the vector data.

There are mainly two methods for converting the raster data into vector data. One is a method in which a computer performs image processing on points and lines of raster data to automatically recognize the points and lines, and causes the computer to automatically generate vector data based thereon. In this method, accurate vector data is not always obtained at one time, and the operator converts the vector data into interactive data as needed, as needed. Another method is a method of tracing in which the operator selects points on the raster data line of the cadastral map displayed on the computer screen at appropriate intervals, and sequentially connects these points with straight lines. In this way, first, the raster data of the cadastral map is converted into vector data (Step 22). In this case, it is desirable to shorten the interval between the selected adjacent points in the curved portion.

Next, the survey data obtained by the actual survey is taken into a computer. This survey data corresponds to the dotted line in FIG. On a screen obtained by converting the cadastral map into vector data, data obtained by surveying, point numbers, and the like are input as attribute values for each point constituting the image ground (Step 23). Specifically, select each point,
For each of the selected points, actual measurement data is input and registered one by one as attribute data. Thereby, the data of each point of the vector data of the cadastral map is associated with the actually measured data. Even if such an operation is performed, there is no particular change on the computer screen. Even in this case, as in the case of FIG. 3, accurate survey data can be linked to each point of the cadastral map converted into vector data.
As in the case of FIG. 3, if necessary, the drawing is output by a plotter or the like (Step 24), or the survey data assigned as attribute data is converted to a Cima format and output (FIG. 3). Step 25) You can.

In the procedure shown in FIG. 4, when survey data is obtained only for a part of the image ground, a part of the vectorized data based on the cadastral map is used.
This is useful in that the obtained survey data can be provided as attribute values. In this case, it is also possible to easily display which part of the completed and displayed map is actually measured or based on the cadastral map by color coding or the like.

The cadastral map according to the present invention includes a public map. The computer program for executing the above-described operation is recorded or stored in whole or in part on a portable medium such as a floppy disk, a CD-ROM, or a storage device such as a hard disk. The program is read by the computer,
All or part of the operation is executed.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the invention. For example, in the above-described embodiment, a case has been described in which data based on a cadastral map is used as an example of the map data. However, the present invention may be further modified based on various map data.
This can be converted into vector data and stored together with the survey data. For example, in addition to public maps such as cadastral maps,
Data based on the current topographical map, planned data of buildings and bridges to be constructed, etc. are also included in the map data of the present invention, and these map data and actual survey data are stored together, and if necessary, plotted with a plotter. It is also possible to output.

[0029]

As described above, according to the present invention,
The cadastral map data and the survey data obtained by actual surveying can be linked and saved, and if necessary, either or both data can be displayed on the screen. If the data is stored according to the present invention, the survey data can be used any number of times, and waste can be reduced.Moreover, since the cadastral map data is converted into vector data, the data amount is small. In addition, since it is now possible to collectively manage survey data that has been separately managed for each department, if the use of the present invention is advanced, for example, surveying is performed when a gutter is made Then, by linking the data to the cadastral map and storing it, the data can be reused the next time a road is created or widened at the gutter. Omitting duplication of effort, increase the efficiency of the surveying operation, and can reduce operating costs.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a relationship between a cadastral map of a land and data obtained by actual surveying.

FIG. 2 is a diagram showing a cadastral map of a certain plot and a diagram based on survey data together to explain the correspondence between a cadastral map and a map based on actual survey data.

FIG. 3 is a flowchart illustrating a procedure for storing data of a cadastral map and surveying data in association with each other.

FIG. 4 is a flowchart showing a procedure for linking and storing cadastral map data and survey data by a method different from that of FIG. 3;

Claims (6)

[Claims] 1. For each predetermined point of cadastral map data vectorized based on cadastral map raster data, survey data obtained by surveying corresponding to that point is provided as relational data, and the vector data A cadastral map data management method characterized by being stored together with the data. 2. The cadastral map data management according to claim 1, wherein only one or both of the vectorized data and the data obtained by the survey are displayed in an overlapping manner. Method. 3. Raster data from which a cadastral map is read,
A step of displaying on a display device together with a diagram obtained based on the survey data of the land obtained by surveying, a predetermined point on the diagram obtained based on the survey data,
Correlating a point corresponding to the predetermined point on the raster data, superimposing and displaying a diagram obtained based on the survey data on the raster data, and vectorizing the raster data; A point on the vector data obtained by the vectorization step corresponding to a point, the survey data corresponding to the point is provided as relational data, and the step of storing the data together with the vectorized data is included. Characteristic cadastral map data management method. 4. The method according to claim 1, wherein one or both of the vector data vectorized in the vectorization step and a diagram obtained based on the survey data are displayed in an overlapping manner. 3. The cadastral map data management method described in 3. 5. A computer having, for each predetermined point of cadastral map data vectorized based on cadastral map raster data, surveying data obtained by surveying corresponding to the point as relational data, A computer-readable recording medium having recorded therein a cadastral map data management program for executing a function of storing the data together with the vector data. 6. A function of displaying, on a display device, a computer together with raster data obtained by reading a cadastral map and a map obtained based on survey data of the land obtained by surveying; Predetermined points on the diagram obtained based on the data,
A function of relating a point corresponding to the predetermined point on the raster data, superimposing and displaying a figure obtained based on the survey data on the raster data, and vectorizing the raster data, A point on the vector data obtained by the vectorization step corresponding to the point, the survey data corresponding to the point is provided as relational data, and a function of storing the data together with the vectorized data is provided. A computer-readable recording medium having recorded thereon a data management program.