KR20150097972A

KR20150097972A - Uncertain boundary detecting system of cadastral data and method thereof

Info

Publication number: KR20150097972A
Application number: KR1020140018912A
Authority: KR
Inventors: 유기윤; 조성환
Original assignee: 서울대학교산학협력단
Priority date: 2014-02-19
Filing date: 2014-02-19
Publication date: 2015-08-27
Also published as: KR101555989B1

Abstract

The present invention relates to a system and method for detecting uncertain regions of cadastral data, the system according to the present invention is an uncertain region detection system for detecting uncertain regions of parcels represented by polygons in cadastral data, A triangulation unit for performing Constrained Delaunay Triangulation (CDT) with respect to the edge of the polygon object as a reference point for triangulation of the vertex of the polygon object; A tagging unit for tagging each of the triangles with the number of the divided triangles to overlap each other; And a detection unit for detecting the uncertain region based on the tagged value. Through this, it is possible to efficiently detect an uncertain region where there is a gap between polygon sets or overlapping by applying a space division technique.

Description

Technical Field [0001] The present invention relates to a system and method for detecting uncertain regions of cadastral data,

The present invention relates to an uncertain region detection system and method for intelligent data, and more particularly, to a system and method for detecting redundant regions and blank regions that occur due to inadequate proximity of a polygon boundary to surrounding polygons in intelligent data And a method thereof.

The cadastre is a content that notifies the location, form, area, use, and ownership of the land. The bounded boundary constitutes one parcel, and the shape of each parcel is expressed using a polygon. At this time, the neighboring polygons must be precisely adjacent to each other, and the topology integrity must be ensured so that they do not overlap each other or have no spaces.

However, in the process of digitization of cadastral maps, including the relaxation and contraction of intellectual circles that have been stored for a long time in the cadastre library, errors arising in vectorizing cadastral maps, problems of differences in surveying due to the use of different reference points, The cognitive data set has a topological contradiction due to various factors such as the transfer of numerical errors when applied to the server. This phenomenon occurs more frequently if not stored / managed through a centralized intellectual database.

The most basic method for constructing a consistent topological database is to re-survey uncertain areas of intellectual in one institution and to integrate management of global cadastral data for topological integrity . However, the above process is difficult to be realized within a short period of time and it is difficult to realistically realize it because it requires a lot of financial investment.

Therefore, many studies have been conducted to derive a solution for checking / detecting the topological integrity. Many methods have been developed to use approximate threshold values around polygon boundaries in order to find adjacent objects as a result. One of the results of this study is the Sweep Band Status (SBS) method (Klajnsek, G. and Zalik, B. (2005), Merging polygons with uncertain boundaries. Computers & Geosciences, Vol.31, No.3, pp.353- 359) have been proposed. This method computes the distance from a specific point p to the other edge, and classifies it as an uncertain region if the calculated distance is smaller than a predetermined threshold distance. According to this method, since the user has to repeatedly check the result while adjusting the threshold value according to the result, there is a problem that the uncertain region which is troublesome and is missed according to the applied threshold value occurs.

The applicant of the present invention has solved the problems of the prior art as described above and proposed a detection system capable of preventing omission of an uncertain region and improving the reliability of the result even after a simple process.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a detection system and method which can prevent detection of an uncertain region in cadastral data and improve the reliability of the detection result.

According to an aspect of the present invention, there is provided an uncertain region detection system for detecting uncertain regions of parcels expressed by polygons in cadastral data according to an embodiment of the present invention, A triangulation performing unit that performs constrained delaunay triangulation (CDT) on the edge of the polygon object as a restriction condition; A tagging unit for tagging each of the triangles with the number of the divided triangles to overlap each other; And a detection unit for detecting the uncertain region on the basis of the tagged value.

The detection unit may detect a triangular area having the tagged value of 0 or greater than 1 as the uncertain area, and the detection unit may set the triangular area having the tagged value of 0 as a blank area, The uncertainty region can be distinguished from the triangular region larger than 1 by the overlap region.

The detecting unit may combine neighboring triangles having the same tagged value and connectivity among the triangles detected as the uncertain region.

According to another aspect of the present invention, there is provided a method of detecting an uncertain region of parcels expressed by polygons in a cognitive data, the method comprising the steps of: (a) recognizing vertices and edges of a polygon object constituting the cadastral data ; (b) performing constrained delaunay triangulation (CDT) on the cadastral data with the recognized vertex as a reference point of triangle generation and with the edge as a constraint; (c) tagging the number of triangles of the triangles by the triangles; And (d) detecting an uncertain region based on the tagged value. &Lt; Desc / Clms Page number 10 >

In this case, the step (d) may detect the uncertain region as a triangle having a tagged value of 0 as a blank region and a triangular region having a tagged value greater than 1 as an overlapped region, (e) Merging neighboring triangles having the same tagged value and connectivity among the triangles detected as the regions.

As described above, according to the present invention, it is possible to efficiently detect an uncertain region in which spaces between polygon objects exist or overlap by applying a space division technique.

1 is a block diagram of an uncertain region detection system of cadastral data according to an embodiment of the present invention;
2 is a reference diagram for explaining the Neuron triangulation;
FIG. 3 is a side view for explaining a limited overhead triangulation; FIG.
FIG. 4 is a flowchart illustrating a process of detecting an uncertain region of cadastral data by the system of FIG. 1; FIG.
Figure 5 is an example showing the result of performing limited overtone triangulation on a piece of cadastral data;
6 is an example showing the result of performing tagging on the divided triangles; And
7 is a diagram schematically illustrating an example of region merging according to a tagging value.

The uncertain region described in this specification includes a blank area (gaps) that is not adjacent to overlaps where polygon objects constituting parcels of intellectual data overlap with each other and which is blank.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

1 is a block diagram of an uncertain region detection system of cadastral data according to an embodiment of the present invention. Referring to FIG. 1, an uncertain region detection system of cadastral data according to an embodiment of the present invention includes a triangulation performing unit 10, a tagging unit 30, and a detecting unit 50.

The triangulation performing unit 10 performs Constrained Delaunay Triangulation (CDT) on cadastral data to divide polygon objects into triangular areas. The limited Delaunay triangulation is a Delaunay Triangulation (DT) technique with a constraint added thereto, which will be described below with reference to FIGS. 2 and 3. FIG.

Fig. 2 is a perspective drawing for explaining the Neuron triangulation, and Fig. 3 is a view for explaining the restricted Neuron triangulation.

The trine triangulation is a method of dividing the space by connecting the points on the plane with triangles so that the minimum value of the interior angles of these triangles is maximized. As shown in FIG. 2 (a), a method of connecting the upper points may be variously described. However, according to the Amore triangulation, And the circumscribed circle of any triangle is divided so that it does not include any other points except the three vertexes of the triangle.

The constrained threesome triangulation is a segmentation technique that adds constraints to the above triangulation. According to this, the area where the triangles can be generated is divided into lines, and the triangles generated as the restriction condition are divided so as not to exceed the lines given above. When a constrained circumferential triangulation is performed in a situation where a thick line is given as a constraint condition as shown in FIG. 3 (a), it is divided into a triangle that does not exceed the line of the constraint condition as shown in FIG. 3 (b). In this way, the triangulation method is a known method of dividing a given space into triangles under the constraint that the triangulation region is limited to a line. Therefore, the description will be omitted for the sake of simplicity.

The triangulation performing unit 10 recognizes the vertices and edges constituting the polygon object of the cadastral data. For reference, when cadastral data information is given as a set of point values constituting a polygon object, the point value becomes a vertex point, and the lines connecting the above points can be recognized as corners. The recognized vertex is used as a reference point for triangulation when triangulation is performed, and the limited triangulation is performed using the edge as a constraint. For reference, triangulation allows to be performed both inside and outside the polygon boundary. This is because if the triangulation is performed only for the inside of the boundary, the blank area can not be detected later. The result of dividing all the spaces in the cadastral data into triangles is the basis for recognizing redundant and blank areas between data sets generated by different jurisdictions.

The tagging unit 30 determines whether or not the triangle faces overlap each other while traversing the triangles divided by the triangulation performing unit 10, and tags the resultant value to each triangle. For example, if two of the divided triangular areas are overlapped, a tagging value can be assigned to the overlapping triangular area, and if the triangular area is included only in a single polygon area, the tagging value can be assigned to one. In addition, if there is no area in which the triangle area is overlapped and if it does not belong to any polygon area, the tagging value is given as 0. On the other hand, the triangular area may be superimposed on three or more polygons, so that three or more tagging values may be given. As described above, the tagging unit 30 assigns the number of overlapping triangles to each triangle as a tagging value.

The detection unit 50 detects an uncertain region in the intellectual data based on the tagged value. Since the polygons neighboring in the cadastral data must be precisely adjacent to their edges, the detection unit 50 determines that the triangular region to which the tagging value is set to 0 is a blank region, and the triangular region to which the tagged value is larger than 1 Is an area that is included in all of two or more polygons, and therefore, it is detected as an uncertain area as an overlapped area. On the other hand, the triangular area having the tagging value of 1 corresponds to an area having a topological integrity that is not overlapped or blank.

The detection unit 50 merges the triangles detected in the uncertain region, i.e., the tagged values of the tagging values of 0 or greater than 1, and the adjacent triangles of the adjacent regions to form an uncertain region . At this time, it is possible to easily determine the type of the uncertain region by marking the regions merged with other tagging values using different markers. For example, the color of the merged region as the tagging value 0, the region merged with the tagging value 2, and the region merged with the tagging value 3 may be displayed differently.

FIG. 4 is a flowchart illustrating a process of detecting an uncertain region of cadastral data by the system of FIG. 1, and FIGS. 5 to 7 are diagrams illustrating a process of detecting an uncertain region. Hereinafter, a method of detecting an uncertain region of cadastral data according to an embodiment of the present invention will be described with reference to FIGS. 4 to 7. FIG.

The vertex and the edge are recognized in the polygon object constituting the parcel of the cadastral data, and limited delineated triangulation is performed on the cadastral data (S10, S11). At this time, the vertex of the recognized polygon becomes a reference point of triangle generation in the triangulation, and the edge of the polygon is applied as a restriction condition.

FIG. 5 (b) is a graphical representation of the result of performing the limited perone triangulation on the polygon objects of a given cadastral data as shown in (a). Thus, the triangulation is performed for a given area including the inside and outside of the polygon boundary. For reference, (a) is an example of intellectual data including two polygon objects. In order to facilitate understanding of the explanation, the markings inside each polygon object are expressed differently.

When the triangulation is completed, the number of triangles to be superimposed on each other is determined while circulating the divided triangles, and the number is added to the corresponding triangles as a tagging value (S13). Fig. 6 schematically shows the result of assigning a tagging value to each of the divided triangles. Referring to FIG. 6, a triangle belonging to a single polygon is given a tagging value of 1 as a topological integrity region, a portion where two polygon regions overlap is a tagging value 2 as a redundant region, and a triangular region Tagging value 0 is given as a blank area.

S15 is an uncertain region extracted by merging neighboring triangles having tagging values equal to or greater than 0 and greater than or equal to 1 and having connectivity. Referring to FIG. 7, it can be seen that an area having a tagging value of 0 and an area having a tagging value of 2 are displayed separately. In this case, in order to easily distinguish the shape of the uncertain area, markings may be displayed differently depending on the tagging value or the overlap area / blank area.

The above-described process may be appropriately added or modified depending on the situation. For example, the step of receiving the census data to be analyzed from an external server may be further included, or the topological integrity area may not be re-surveyed or changed. Therefore, before performing the merge of triangles, The value may further include a step of removing.

As can be seen from the above description, the uncertain region detection system of the cadastral data according to the embodiment of the present invention can detect an uncertain region where the detection is missed by the conventional manual method or the method using the threshold value, And the time required for processing can be shortened by eliminating the cumbersome process of repeatedly changing the threshold value according to the method using the threshold value.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art to which the invention pertains. It will be possible.

For example, a user interface may be constructed to provide a function of selectively displaying an area requested by a system user such as an area display having a specific tagging value and an uncertain area display exceeding a predetermined area.

Therefore, it is to be understood that the embodiments of the present invention are to be considered as illustrative only, and that the technical spirit of the present invention is defined from the description of the claims, and the scope of protection is to be applied to the equivalents.

10: triangular division performing unit 30: tagging unit
50:

Claims

1. An uncertain region detection system for detecting uncertain regions of parcels represented by polygons in cadastral data,
A triangulation unit for performing Constrained Delaunay Triangulation (CDT) with respect to the cadastral data with a vertex of the polygon object as a reference point for triangle creation, with the edge of the polygon object as a restriction condition;
A tagging unit for tagging each of the triangles with the number of the divided triangles to overlap each other; And
And a detection unit for detecting the uncertain region based on the tagged value.

The method according to claim 1,
Wherein the detecting unit detects an area of a triangle having the tagged value of 0 or greater than 1 as the uncertain area.

3. The method of claim 2,
Wherein the detection unit distinguishes the uncertain region from the triangular region having the tagged value of 0 as a blank region and the triangular region having the tagged value greater than 1 as an overlap region.

The method according to claim 1,
Wherein the detecting unit merges neighboring triangles having the same tagged value and connectivity among the triangles detected as the uncertain region.

CLAIMS 1. A method for detecting an uncertain region of parcels represented by polygons in intelligent data,
(a) recognizing vertexes and edges of a polygon object constituting the cadastral data;
(b) performing constrained delaunay triangulation (CDT) on the cadastral data with the recognized vertex as a reference point of triangle generation and with the edge as a constraint;
(c) tagging the number of triangles of the triangles by the triangles; And
(d) detecting an uncertain region based on the tagged value.

6. The method of claim 5,
Wherein the step (d) detects the uncertain region by using the triangular region having the tagged value of 0 as a blank region and the triangular region having the tagged value of greater than 1 as overlapping regions.

6. The method of claim 5,
(e) merging adjacent triangles having the same tagged value and connectivity, among the triangles detected as the uncertain region. < Desc / Clms Page number 13 >