Map evaluation apparatus, method for evaluating map, and map evaluation program

Abstract

To provide a map evaluation apparatus, a method for evaluating a map, and a map evaluation program for expressing differences among multiple maps that should be in the same state as objective numerical values and easily extracting areas that need to be preferentially corrected.SOLUTION: When a parcel specifying unit (10) specifies a parcel to be compared between a first map and a second map, an outline coordinate value extraction unit (12) extracts a first outline from the first map and a second outline from the second map as coordinate values of vertices defining the respective outlines. A matching processing unit (20) determines pairs of corresponding vertices between the first outline and the second outline on the basis of the coordinate values of the vertices defining the respective outlines, and also determines isolated vertices for which no corresponding vertex can be determined. An evaluation data generation unit (16) generates evaluation data on the basis of the pairs of vertices and the presence or absence of isolated vertices, and an evaluation unit (18) evaluates the difference in the outlines between the first map and the second map from the evaluation data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a map evaluation device, a map evaluation method, and a map evaluation program. [Background technology]

[0002] There are maps kept at Legal Affairs Bureaus (hereinafter referred to as Legal Affairs Bureau official maps) that show the shape of each parcel of land, including its boundaries, location, and parcel number. Legal Affairs Bureau official maps include highly accurate maps based on the public coordinate system, with land boundaries determined through cadastral surveys (maps based on Article 14, Paragraph 1 of the Real Estate Registration Act: referred to as Article 14 maps), and maps based on maps (abutment maps) created during the land tax reform in the early Meiji period (maps attached to the old cadastral register: referred to as old official maps). Old official maps are created using arbitrary coordinates within the map, and the orientation of the map is also arbitrary.

[0003] Each city, town, and village has prepared current parcel number maps, similar to official maps from the Legal Affairs Bureau, which show the boundaries, location, and parcel shape of each parcel, including parcel numbers, as the basis for assessing fixed asset tax on land. If the official maps from the Legal Affairs Bureau are Article 14 maps, they are based on the current state of the land and can be used for tax purposes without any problems. However, in the case of old official maps, the orientation varies from map to map, and the shape of the parcels does not necessarily reflect the current state, which makes it difficult to use them as taxation information. Therefore, using accurately surveyed topographical maps and aerial photographs, etc., local governments have compiled current parcel number maps by editing the old official maps to match the current state.

[0004] For example, Patent Document 1 below discloses an invention of a map alignment device that semi-automates the work of embedding a legal affairs bureau official map into a residential map, thereby improving work efficiency. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-032810 Summary of the Invention [Problem to be solved by the invention]

[0006] While the official maps of the Legal Affairs Bureau and the current parcel number maps should be identical in nature, since the current parcel number maps were created, the Legal Affairs Bureau and municipalities have made additions and deletions to their respective maps to account for changes in the shape of plots over time, such as the division and merging of plots due to residential land development and the opening of new roads, which can lead to discrepancies between the two maps due to inconsistencies in the accuracy of editing and, in some cases, errors during corrections. Therefore, both maps are periodically inspected by municipal tax officials or contracted contractors, but depending on the municipality, visually inspecting every single parcel of land, which may consist of tens of thousands or even hundreds of thousands of plots, requires a considerable amount of effort and skill.

[0007] Therefore, the object of the present invention is to provide a map evaluation device, a map evaluation method, and a map evaluation program that can easily extract areas that require priority correction by objectively expressing the discrepancy (difference) between multiple maps that should be identical, such as official maps from the Legal Affairs Bureau and current land lot status maps, in numerical terms. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention includes the following embodiments. [1] A map evaluation device for evaluating differences between a first map and a second map representing stroke shapes, comprising: a stroke designation unit for designating strokes to be compared in the first map and the second map; an outline coordinate value extraction unit for extracting a first outline from the first map and a second outline from the second map as the outlines of the strokes to be compared designated by the stroke designation unit, as coordinate values ​​of vertices that define each outline; a matching processing unit for determining pairs of corresponding vertices between the first outline and the second outline based on the coordinate values, and determining whether or not there are isolated vertices for which corresponding vertices cannot be determined; an evaluation data generation unit for generating evaluation data based on the pairs of vertices and the presence or absence of isolated vertices; and an evaluation unit for evaluating differences between the first map and the second map based on the evaluation data. A map evaluation device comprising: [2] The map evaluation device described in [1], wherein the evaluation unit evaluates the differences between the first map and the second map based on the distance between vertices in the set of vertices generated by the evaluation data generation unit and the presence or absence of isolated vertices. [3] The map evaluation device according to [2], wherein the evaluation unit is capable of changing the weighting of the evaluation of the distance between the vertices in the set of vertices and the presence or absence of the isolated vertex. [4] The map evaluation device described in any one of [1] to [3], wherein the evaluation data generation unit excludes each isolated vertex from being designated as an isolated vertex when the isolated vertex exists, the shortest distance from the isolated vertex to the first outline or the second outline, whichever outline does not have the isolated vertex, is less than a predetermined threshold, and the interior angle at each isolated vertex is greater than a predetermined threshold. [5] The map evaluation device described in [1] further comprises a conversion unit that, when the coordinate systems of the first map and the second map are different, converts the coordinate values ​​of one or both vertices of the outlines of the brushes to be compared so that the distance between the vertices defining the first outline and the vertices defining the second outline is minimized, and converts the coordinate values ​​so that the first outline and / or second outline whose coordinate values ​​have been converted maintain similar shapes before and after the conversion, and the matching processing unit determines the pairs of vertices and whether or not there are isolated vertices based on the coordinate values ​​after the conversion. [6] A map evaluation method for evaluating differences between a first map and a second map representing stroke shapes, comprising the steps of: specifying a stroke to be compared in the first map and the second map; extracting a first outline from the first map and a second outline from the second map as the outlines of the specified strokes to be compared, as coordinate values ​​of vertices defining each outline; determining pairs of corresponding vertices between the first outline and the second outline based on the coordinate values, and determining whether there are any isolated vertices for which corresponding vertices cannot be determined; generating evaluation data based on the pairs of vertices and the presence or absence of isolated vertices; and evaluating the differences between the first map and the second map from the evaluation data. [7] A map evaluation program for evaluating the differences between a first map and a second map, characterized by making a computer function as: a stroke designation unit that designates strokes to be compared in a first map and a second map representing stroke shapes; an outline coordinate value extraction unit that extracts a first outline from the first map and a second outline from the second map as the outlines of the strokes to be compared designated by the stroke designation unit, as coordinate values ​​of vertices that define each outline; a matching processing unit that determines pairs of corresponding vertices between the first outline and the second outline based on the coordinate values, and determines whether there are any isolated vertices for which corresponding vertices cannot be determined; an evaluation data generation unit that generates evaluation data based on the pairs of vertices and the presence or absence of isolated vertices; and an evaluation unit that evaluates the differences between the first map and the second map based on the evaluation data. [Effects of the Invention]

[0009] According to the present invention, by expressing the deviations (differences) between a plurality of maps that should be in the same state in objective numerical values, it is possible to easily extract areas that require correction as a priority. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a functional block diagram of an example of a map evaluation device according to an embodiment. [Figure 2] 10A and 10B are explanatory diagrams illustrating operations of a conversion unit and a matching processing unit according to an embodiment. [Figure 3] FIG. 10 is a diagram illustrating an example of a table of evaluation points used by an evaluation unit according to the embodiment. [Figure 4] FIG. 10 is a diagram showing an example of evaluation by an evaluation unit using a table of evaluation points according to the embodiment. [Figure 5] 10A and 10B are diagrams illustrating an example in which curves are included in parts of a first outer shape and a second outer shape according to an embodiment. [Figure 6] FIG. 3 is a flowchart of an example of the operation of the map evaluation device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

[0012] 1 shows a functional block diagram of an example of a map evaluation device 100 according to an embodiment. The map evaluation device 100 includes a stroke designation unit 10, an outer coordinate value extraction unit 12, a conversion unit 14, an evaluation data generation unit 16, an evaluation unit 18, a matching processing unit 20, a communication unit 22, a display control unit 24, a storage unit 26, an input unit 28, and a CPU 30, and is configured as a computer that controls the entire device and performs various calculations. The CPU 30 may include an accelerator such as a GPU in addition to the CPU.

[0013] The stroke designation unit 10 designates a parcel to be compared between a first map, such as a public map issued by the Legal Affairs Bureau, and a second map, such as a current parcel number map, which are maps showing the shape of parcels, by a parcel number or a reference number that is a common number assigned to the same parcel on both maps. Information on the first and second maps may be acquired via the communication unit 22 from a server provided in, for example, a Legal Affairs Bureau or a municipality and stored in the storage unit 26, or information pre-stored in a USB or other appropriate storage medium may be read via the communication unit 22 and stored in the storage unit 26. The process of designating a parcel to be compared by the stroke designation unit 10 is executed by storing information on the parcel to be compared (such as a parcel number or reference number) included in instruction information input from the input unit 28 in the storage unit 26. The above instruction information is input by the user via the input unit 28, and can include multiple parcels to be compared; all parcels in each city, town, or village can be targeted, or a town or area or a specific area on a public map of the Legal Affairs Bureau can be specified, or a single or multiple parcels can be specified from the screen of a current land number map displayed on an LCD display or the like.

[0014] The contour coordinate value extraction unit 12 reads information about the stroke to be compared, specified by the stroke designation unit 10, from the storage unit 26 and extracts a first contour from the first map and a second contour from the second map as contours representing the stroke shape of the stroke, using the coordinate values ​​of the vertices defining each contour. Here, the first contour and the second contour are contours to be compared, and therefore are contours for the same stroke on the first and second maps. If there are multiple strokes to be compared, the first contour and the second contour corresponding to each stroke are extracted sequentially according to a predetermined rule. The contour of the stroke is the boundary line of a closed area, such as a rectangle or polygon, representing a land plot, and is composed of multiple sides whose starting and ending points are the coordinate values ​​of each extracted vertex. The contour coordinate value extraction unit 12 stores the coordinate values ​​of the vertices defining the first contour and the second contour, contained in the first and second map information read from the storage unit 26, in the storage unit 26 as a set of the first contour and the second contour of the same stroke. In this case, a vertex code for identifying the vertex position may be assigned to each vertex of each contour and stored together with its coordinate value.

[0015] If the first and second maps have different coordinate systems, the conversion unit 14 converts the coordinate values ​​of one or both of the vertices defining the first outline and the second outline read from the storage unit 26 to create a single coordinate system. Specifically, the conversion unit 14 performs a certain number of additions and subtractions, and, if necessary, multiplications and divisions, on the coordinate values ​​of the outline of the parcel on the first map (official map of the Legal Affairs Bureau), which is an arbitrary coordinate system, to make the coordinate values ​​close to the outline of the parcel on the second map (current parcel number map). At this point, it is sufficient if the approximate locations are close. Once the coordinate values ​​of the vertices of each outline are in the same coordinate system, the conversion unit 14 converts the coordinate values ​​of the outline of one map to the coordinate values ​​of the outline of the other map, for example, by moving, rotating, enlarging, or reducing the coordinate values ​​while maintaining the similarity of the outline shape. In this case, the conversion unit 14 performs a transformation process, such as moving or rotating, to minimize the sum of the errors between the coordinate values ​​of the corresponding vertices of the first and second outlines. Here, the coordinate value conversion method can be, for example, an affine transformation or a homography transformation. The rotation angle, amount of movement, magnification, and reduction ratio may be the same as the values ​​of other plots described in the same first map (official map of the Legal Affairs Bureau) for which conversion processing has already been completed. The coordinate values ​​of each vertex of one or both of the first and second outlines after conversion are stored in the memory unit 26. Information about the first and second outlines after conversion processing, i.e., the coordinate values ​​of one or both of the vertices of the first and second outlines, is also stored in the memory unit 26 as a set for each plot.

[0016] The matching processor 20 reads from the memory unit 26 the coordinate values ​​of the vertices defining the first and second outer shapes stored as pairs, and determines pairs of corresponding vertices between the first and second outer shapes based on the read coordinate values. If the first and second outer shapes differ in the number of vertices constituting the shapes, or if the positions of the vertices that should correspond are significantly different, and corresponding vertices cannot be determined, the matching processor 20 determines whether or not the vertices are isolated vertices. If the converter 14 converts the coordinate values ​​of one or both of the vertices defining the first and second outer shapes, the converted coordinate values ​​are read from the memory unit 26 and used. The matching processor 20 stores the coordinate values ​​of the pairs of corresponding vertices between the first and second outer shapes, as well as the coordinate values ​​of isolated vertices for which corresponding vertices cannot be determined, in the memory unit 26. In this case, information on the combination of vertex codes of the corresponding pairs of vertices and the vertex codes of the isolated vertices may be recorded. Details of the processing by the matching processor 20 will be described later.

[0017] The evaluation data generation unit 16 reads the coordinate values ​​of the corresponding vertices, and if there is an isolated vertex for which a corresponding vertex cannot be determined, the coordinate values ​​of the vertex from the storage unit 26, and generates evaluation data based on the vertex pair and the presence or absence of the isolated vertex. The evaluation data includes the distance between the vertices in the vertex pair, the angle between the edges of the first and second contours, which have corresponding vertices as their endpoints, i.e., the difference between the interior angles in the first and second contours. If an isolated vertex exists, the presence or absence of the isolated vertex itself or the distance between the isolated vertex and the other edge is used as evaluation data. The process of determining the other edge will be described later. The evaluation data generated by the evaluation data generation unit 16 is stored in the storage unit 26.

[0018] The evaluation unit 18 reads the evaluation data generated by the evaluation data generation unit 16 from the storage unit 26 and evaluates the differences between the first and second maps by evaluating the differences in the contours of the same parcels on the first and second maps based on the evaluation data. The evaluation unit 18 performs the evaluation by, for example, creating a table of evaluation scores in advance for the distance between vertices defining the first and second contours combined by the matching unit 20, and for the cases where isolated vertices exist on the first and second maps, respectively, and then scoring the differences between the first and second maps based on this table. The evaluation results are tallied for each parcel and stored in the storage unit 26. The evaluation unit 18 may also store evaluation results tallied for each parcel, such as for each block, each official map, or each town / district, in the storage unit 26, as needed. The evaluation unit 18 may also rank the parcels and the blocks, which are the aggregation units, in descending order of the evaluation scores for each parcel or the tallied evaluation scores. This ranking indicates the degree of need for correction. In this way, the evaluation unit 18 evaluates the differences between the first map and the second map based on the aggregated evaluation results and the ranked evaluation results. The evaluation results stored in the memory unit 26 are displayed on an appropriate display device by the display control unit 24 (to be described later).

[0019] The communication unit 22 is configured with an appropriate interface, and performs processing such as acquiring data such as information on the first map and the second map from an external server or the like, and storing the data in the storage unit 26.

[0020] The display control unit 24 controls a liquid crystal display device or other appropriate display device based on instructions from the outer shape coordinate value extraction unit 12, the evaluation unit 18, etc., to display the first outer shape, the second outer shape, the evaluation results by the evaluation unit 18, etc. In particular, the display control unit 24 has a function to control the map display of the first map, the second map, etc., and can display a comparison of the first outer shape and the second outer shape of the corresponding parcel on a liquid crystal display device, etc., to visually confirm the difference in the outer shapes, or, for example, can display a current parcel number map, which is the second map, and then highlight the problematic parcel to easily confirm the priority areas for correction work.

[0021] The storage unit 26 is composed of nonvolatile memory such as a hard disk drive or solid-state drive (SSD), and stores information necessary for the various processes performed by the map evaluation device 100, such as the above-mentioned data and programs for operating the CPU 30. The storage unit 26 may also be a digital versatile disc (DVD), compact disc (CD), magneto-optical disc (MO), flexible disk (FD), magnetic tape, electrically erasable and rewritable read-only memory (EEPROM), flash memory, or the like. The storage unit 26 preferably includes random access memory (RAM), which primarily functions as a working area for the CPU 30, and read-only memory (ROM), which stores control programs such as the BIOS and other data used by the CPU 30. The storage unit 26 may also include an external storage device.

[0022] The input unit 28 is composed of appropriate input means such as a keyboard, a pointing device such as a mouse, a touch panel, etc., and is used by the user to input instruction information, etc.

[0023] 2(a), (b), (c), and (d) are explanatory diagrams of the operation of the conversion unit 14 and the matching processing unit 20. FIG. 2(a) shows a first outline extracted from a first map, and the outline is defined by vertices A, B, C, D, and E. FIG. 2(b) shows a second outline extracted from a second map, and the outline is defined by vertices A', B', C', and D'. The first and second maps are maps that include the same parcel (for example, a Legal Affairs Bureau official map and a parcel number current status map), and the first and second outlines are the outlines of the same parcel to be compared.

[0024] In Figures 2(a) and 2(b), the first and second maps use different coordinate systems. This may occur, for example, when the first map is created using arbitrary coordinates within a drawing, and the second map is created using a public coordinate system. The conversion unit 14 unifies the first and second outlines (e.g., the first outline created using arbitrary coordinates) into the same coordinate system by adding or subtracting a certain value to each coordinate, or multiplying or dividing as necessary. Detailed alignment is not required at this stage. Furthermore, once the first and second outlines (e.g., the first outline created using arbitrary coordinates) are aligned into the same coordinate system, they are similarly moved, enlarged, reduced, rotated, or otherwise adjusted to minimize the distance between the vertices (A, B, C, D, E) defining the first outline and the vertices (A', B', C', D') defining the second outline. Fig. 2(c) shows the state in which the first and second contours are superimposed (the state in which the distances between the vertices are minimized) after the conversion process by the conversion unit 14. In the example of Fig. 2(c), the first contour is shown by a solid line and the second contour is shown by a dashed line.

[0025] In addition, if the coordinate systems of the first map and the second map are unified, for example, using a public coordinate system, the first outline and the second outline will be in the state shown in Figure 2(c) without conversion by the conversion unit 14, and the matching processing unit 20 can directly determine the vertex pairs, and the evaluation data generation unit 16 can directly generate the evaluation data.

[0026] The matching processor 20 determines a pair of corresponding vertices between the first and second outer shapes based on the coordinate values ​​of the vertices that define the first and second outer shapes. Specifically, the matching processor 20 determines the pair of vertices by performing the following two-stage determination. Step (I): From the coordinate values ​​of the vertices (A, B, C, D, E) that define the first outline and the vertices (A', B', C', D') that define the second outline, the distances between each of the vertices A, B, C, D, E and each of the vertices A', B', C', D' are calculated, and it is determined whether the distance between each of the vertices is equal to or less than a predetermined first threshold. Two points whose mutual distance is equal to or less than the first threshold are extracted as a pair of vertices. Step (II): In step (I), a pair of vertices whose distance is less than a first threshold is extracted, and it is determined whether the difference in the interior angles of the first outline and the second outline at each vertex of the pair of vertices is less than a predetermined second threshold.

[0027] In this way, in stage (I), a pair of vertices whose mutual distance is equal to or less than a first threshold is extracted, and in stage (II), when the difference between the interior angles of the pair of vertices is equal to or less than a second threshold, the matching processing unit 20 sets the pair of vertices as a pair of corresponding vertices between the first outer shape and the second outer shape, and determines the vertices for which a pair of corresponding vertices cannot be formed as isolated vertices.

[0028] For example, in the case of FIG. 2(c), if the distance between vertex A defining the first outer shape and vertex A' defining the second outer shape is the smallest compared to the distances to the other vertices and is equal to or less than a first threshold, vertex A and vertex A' are selected as a pair of vertices extracted in step (I). Next, for vertex B adjacent to vertex A defining the first outer shape and vertex B' adjacent to vertex A' defining the second outer shape in the same direction as the first outer shape, if the distance between the vertices is equal to or less than the first threshold, the two are selected as a pair of vertices. If the distance between the vertices exceeds the first threshold, the distance between vertex B defining the first outer shape and vertex C' adjacent to vertex B' defining the second outer shape is verified in sequence, with vertex B defining the first outer shape fixed, or with vertex B' defining the second outer shape and vertex C adjacent to vertex B defining the first outer shape, to search for pairs whose distance between the vertices is equal to or less than the first threshold. Vertices that do not form a corresponding vertex pair are determined as isolated vertices, and a determination is made for all vertices as to whether they form a vertex pair or whether they are isolated vertices. In the example of Figure 2(c), the distance between vertices C and C', and vertices D and D' is also less than or equal to the first threshold, and each is a pair of vertices extracted in step (I). Next, for one of these pairs of vertices, for example, vertices A and A', it is determined in step (II) whether the difference between the interior angle (angle D'A'B') at vertex A of the first outline and the interior angle (angle D'A'B') at vertex A' of the second outline is less than or equal to the second threshold. Similarly, the difference in the interior angles between vertices B and B', vertices C and C', and vertices D and D' that form a pair of vertices is determined. If the difference in the interior angles exceeds the second threshold, the pair of vertices is dissolved, and each is determined as an isolated vertex.

[0029] Furthermore, vertex E shown in Figures 2(a) and (c) is an example of a vertex that exceeds at least one of the first threshold value or the second threshold value in the judgment of either stage (I) or stage (II), and is determined by the matching processing unit 20 to be an isolated vertex for which a corresponding vertex cannot be determined.

[0030] 2(d) shows an example in which the coordinate values ​​of vertex F defining the first outline shown by the solid line and vertex F' defining the second outline shown by the dashed line match, the distance between vertex F and vertex F' is equal to or less than the first threshold, but the difference in the interior angles at each vertex exceeds the second threshold. In the example of FIG. 2(d), the interior angle at vertex F is indicated by θ, the interior angle at vertex F' is indicated by θ', and the difference between θ and θ' (θ-θ') exceeds the second threshold. In such a case, the matching processor 20 also determines vertex F and vertex F' as isolated vertices for which a corresponding vertex cannot be determined.

[0031] The evaluation data generation unit 16 calculates the distance between the vertices defining the first and second outer shapes from the coordinate values ​​of the vertices defining the first and second outer shapes in pairs of corresponding vertices (pairs of vertices A and A', B and B', C and C', and D and D') between the first and second outer shapes shown in FIG. 2(c), and sets the distance as evaluation data for each point. Furthermore, when the matching processing unit 20 is executing a process for determining an isolated vertex such as vertex E, the evaluation data generation unit 16 generates evaluation data based on the presence or absence of an isolated vertex. Specifically, it is preferable to generate evaluation data for each isolated vertex based on the presence or absence of an isolated vertex itself, or if an isolated vertex exists, and to set the shortest distance between each isolated vertex and the opposite side as evaluation data. The opposite side edge refers to the edge C'D' having both endpoints at the vertices (vertices C' and D' in Figure 2(c)) of the other outer shape (second outer shape or first outer shape) that form a pair of vertices corresponding to the vertices (vertices C and D in Figure 2(c)) on either side of the isolated vertex (vertex E in Figure 2(c)) in the outer shape (first outer shape or second outer shape) where each isolated vertex for which evaluation data is generated exists. Note that even if there are two or more isolated vertices between vertices C and D, edge C'D' will also be the opposite side edge.

[0032] FIG. 3 shows an example of a table of evaluation scores used by the evaluation unit 18. In the example of FIG. 3, evaluation scores are set for the distance g between corresponding vertices, the presence or absence of isolated vertices in the first map, and the presence or absence of isolated vertices in the second map as evaluation items. For the distance g between corresponding vertices, a score of 0.05 is set when 0 < g ≤ 1 m, and a score of 0.25 is set when 1 < g ≤ 2.5 m. A score of 0.25 is set when there are isolated vertices in the first map and the second map. When the distance g between corresponding vertices exceeds 2.5 m, it is not extracted (regarded as an isolated vertex) as a pair of vertices when exceeding the first threshold (2.5 m) in the above stage I.

[0033] The evaluation unit 18 uses the table in FIG. 3 to calculate scores for each distance and number of corresponding vertices, calculates scores according to the number when there are isolated vertices, obtains the total score, and evaluates the difference between the first map and the second map. That is, the larger the total score, the greater the difference between the first map and the second map, so it is possible to easily extract the parts that need to be corrected preferentially from the total score.

[0034] Here, the significance of evaluating isolated vertices can be considered as follows. (1) In most cases, the boundary of the land is determined by driving piles at the location of the boundary on site. The straight line connecting the piles determines the boundary of the land. Here, the pile refers to the vertex of the outer shape on the public map of the legal affairs bureau or the current situation map of the land number. If we want to verify the consistency of the land shape, considering pile = vertex, it is important to verify the vertex positions of the outer shape on the map. (2) On the other hand, as a method of examining the shapes of two types of figures, there is a case where the consistency of the shape is obtained by the ratio of the area of the overlapping area. However, since the boundary of the land is basically determined by piles, no matter how consistent the area is, if there is an error in the actual position of the pile, the judgment of the consistency lacks persuasiveness. (3) Furthermore, if there are missing vertices, it means that the shape is not represented correctly, so isolated vertices become even more problematic, and a figure with missing stake positions, i.e., missing vertex positions, significantly reduces its credibility as a map. (4) Based on the above, isolated vertices are given more importance as an evaluation item.

[0035] 4(a), (b), and (c) show examples of evaluation by the evaluation unit 18 using the evaluation score table shown in FIG. 3. In FIG. 4(a), a first outline of one brush included in the first map is shown by vertices A, B, C, D, E, and F and the solid lines connecting them. A second outline of one brush included in the second map is shown by vertices A', B', C', E', and F' and the dashed lines connecting them. Here, the first outline and the second outline are the outlines of the same brush to be compared between the first and second maps. The first outline and the second outline are the outlines converted by the conversion unit 14 and are superimposed so that the distance between the vertices is minimized.

[0036] In the example of FIG. 4( a), the coordinate values ​​of vertices A and A', vertices B and B', vertices C and C', and vertices F and F' are the same, and vertices A and A', vertices B and B', vertices C and C', and vertices F and F' are determined to be corresponding pairs of vertices by the matching processor 20. Sides AB and A'B', sides BC and B'C', and sides AF and A'F' overlap. Vertices E and E' are also determined to be corresponding pairs of vertices by the matching processor 20 because their distance is less than or equal to the first threshold. The evaluation data generator 16 calculates the distance between vertices E and E' as 1.5 m. Furthermore, vertex D of the first outline is located on side C'E' of the second outline, but there is no vertex in the second outline whose distance is within the first threshold, and therefore the matching processor 20 determines it to be an isolated vertex. Note that side CD overlaps part of side C'E', and side E'F' overlaps part of side EF. Therefore, the portion of the second outline shown by the dashed line is only the line segment connecting vertex D and vertex E'.

[0037] When the evaluation unit 18 evaluates the difference between the first outer shape and the second outer shape in Figure 4(a) using the evaluation score table shown in Figure 3, vertex E and vertex E' are a pair of corresponding vertices, and because the distance between those vertices (1.5 m) is selected, vertex D is an isolated vertex, and so 0.25 is selected as its score. As a result, in the example of Figure 4(a), the score for evaluating the difference between the first outer shape and the second outer shape is 0.25 + 0.25 = 0.5.

[0038] In Figure 4(b), a first outline of one brush stroke included in the first map is shown by vertices A, B, and C and the solid lines connecting them. Also, a second outline of one brush stroke included in the second map is shown by vertices A', B', C', and D' and the dashed lines connecting them. Here, the first outline and the second outline are the outlines of the same brush stroke that are compared between the first map and the second map. Also, the first outline and the second outline are outlines after conversion by the conversion unit 14, and are superimposed so that the distance between each of the vertices is minimized.

[0039] In the example of FIG. 4(b), the coordinate values ​​of vertices A and A', vertices B and B', and vertices C and C' match, and vertices A and A' and vertices B and B' are determined by the matching processor 20 to be a pair of corresponding vertices. Furthermore, although the coordinate values ​​of vertices C and C' match, the difference in angle between the interior angle of the first outline at vertex C and the interior angle of the second outline at vertex C' exceeds the second threshold, and the matching processor 20 determines the vertices as isolated vertices. Note that for vertices A and A', the difference in the interior angles of the first outline and the second outline is equal to or less than the second threshold. Furthermore, sides AB and A'B', and sides BC and B'C' overlap. Furthermore, vertex D' is determined to be an isolated vertex for which a corresponding vertex cannot be determined.

[0040] When the evaluation unit 18 evaluates the difference between the first outer shape and the second outer shape in Fig. 4(b) using the evaluation score table shown in Fig. 3, vertices C, C', and D' are isolated vertices, and therefore a score of 0.25 is selected for each of them. As a result, in the example of Fig. 4(b), the score for evaluating the difference between the first outer shape and the second outer shape is 0.25 x 3 = 0.75.

[0041] In Figure 4(c), a first outline of one brush included in the first map is shown by vertices A, B, C, and D and the solid lines connecting them. A second outline of one brush included in the second map is shown by vertices A', B', C', and D' and the dashed lines connecting them. Here, the first outline and the second outline are the outlines of the same brush that are compared between the first and second maps. The first outline and the second outline are the outlines after conversion by the conversion unit 14, and are superimposed so that the distance between the vertices is minimized.

[0042] In the example of Fig. 4(c), the coordinate values ​​of vertices A and A', vertices B and B', vertices C and C', and vertices D and D' do not match, but are determined to be pairs of corresponding coordinate values ​​by the matching processing unit 20. Here, it is assumed that the distance between vertices A and A' is calculated by the evaluation data generation unit 16 to be 1.5 m, the distance between vertices B and B' and the distance between vertices C and C' are each calculated by the evaluation data generation unit 16 to be 2.0 m, and the distance between vertices D and D' is calculated by the evaluation data generation unit 16 to be 0.5 m.

[0043] When the evaluation unit 18 evaluates the difference between the first outer shape and the second outer shape in Fig. 4(c) using the evaluation score table shown in Fig. 3, it selects 0.25 as a score from the distances (1.5 m and 2.0 m) between vertices A and A', between vertices B and B', and between vertices C and C', and selects 0.05 as a score from the distance (0.5 m) between vertices D and D'. As a result, in the example of Fig. 4(c), the score for evaluating the difference between the first outer shape and the second outer shape is 0.25 × 3 + 0.05 = 0.8.

[0044] From the above results, it can be seen that the difference between the first map and the second map (the first outline and the second outline) is greatest in the order of the example in Figure 4(c) > Figure 4(b) > Figure 4(a), and therefore the need for correction is greatest in the above order.

[0045] The evaluation score table used by the evaluation unit 18 is not limited to the example shown in FIG. 3 . The types of evaluation items and their respective scores (weightings) can be changed as appropriate depending on the conditions of the first and second maps to be evaluated, the evaluation purpose, and the like. Furthermore, for isolated vertices, scores may be set based on the shortest distance between the isolated vertex and the opposite side, rather than on the presence or absence of the vertex. This allows for appropriate evaluation of the maps to be evaluated depending on the conditions of the first and second maps to be evaluated, the evaluation purpose, and the like. If the shortest distance between the isolated vertex and the opposite side is less than a predetermined third threshold (e.g., 2.5 m), the determination of the isolated vertex may be canceled, and the vertex may be excluded from the evaluation of the difference between the first and second outlines. In this case, the condition for excluding the vertex from the evaluation may be a vertex whose interior angle is greater than or equal to a predetermined threshold (e.g., very close to 180 degrees). This facilitates evaluation, particularly when the first and second outlines include curved lines.

[0046] Figures 5(a), (b), and (c) show examples in which the first and second outer shapes include curves. In this case, the curves are actually formed by connecting multiple vertices with relatively short straight edges, and the large interior angles of each vertex represent the curved outer shape. Figure 5(a) shows an example of the first outer shape of a brush included in the first map, with the first outer shape indicated by vertices A, B, and C and the solid lines connecting them. Figure 5(b) shows an example of the second outer shape of a brush included in the second map, with the second outer shape indicated by vertices A', B', and C' and the dashed lines connecting them. The examples in Figures 5(a) and (b) show the first and second outer shapes of the same brush to be compared, respectively, which are the outer shapes after conversion by the conversion unit 14, but are not superimposed. Figure 5(c) shows the first and second outer shapes shown in Figures 5(a) and (b) superimposed so that the distance between each vertex is minimized. As shown in FIG. 5(c), the coordinate values ​​of vertices A and A', vertices B and B', and vertices C and C' match.

[0047] In the examples of Figures 5(a), (b), and (c), the brush boundaries BC and B'C' are the edges of corresponding curves. In the example of Figure 5(c), the vertices defining the shape of this curve BC are indicated by f1, f2, and f3, and the vertices defining the shape of the curve B'C' are indicated by s1, s2, and s3. Note that in the example of Figure 5(c), the shape of each curve is defined by three vertices, but the number of vertices is not limited to this. The greater the number of vertices, the higher the accuracy of the curve. Here, the vertices defining the shape of the curve are set on the curve, and the shape and curvature of the curve are simulated by multiple relatively short straight lines connecting the vertices. However, when representing a curve as described above, if the data was created at different times, it is difficult to align the positions of the vertices passing through the same curve at the same point. Therefore, it is difficult to match the vertices representing the curve, and each vertex becomes an isolated vertex. If evaluated as is, the evaluation score will be higher than necessary, even though the external shapes are nearly identical. In this case, the mutual distance between these vertices f1, f2, f3 and vertices s1, s2, s3 exceeds the first threshold, and even if they are determined to be isolated vertices by the matching processing unit 20, evaluation points for the isolated vertices are not added, and processing is required to evaluate them in such a way that each virtual corresponding vertex exists on the corresponding nearest edge.

[0048] The evaluation data generation unit 16 calculates, as evaluation data, first distances between vertices f1, f2, and f3, which are isolated vertices, and boundary B'C', which is the curved portion of the opposing side of the second outer shape. In the example of FIG. 5(c), three first distances are calculated. Similarly, the evaluation data generation unit 16 calculates, as evaluation data, second distances between vertices s1, s2, and s3, which are isolated vertices, and boundary BC, which is the curved portion of the opposing side of the first outer shape. In the example of FIG. 5(c), three second distances are calculated. If both the first distance and the second distance are equal to or less than the predetermined third threshold, the evaluation unit 18 cancels the determination of vertices f1, f2, and f3 and vertices s1, s2, and s3 as isolated vertices and excludes them from the evaluation of the difference between the first outer shape and the second outer shape. As a result, it is evaluated that there is no difference between the boundaries BC and B'C', which are the curved portions of the first outer shape and the second outer shape. When calculating evaluation data for curves BC and B'C' in FIG. 5(c), the operator can specify in advance via the input unit 28 that curves BC and B'C' are curves, thereby enabling the system to identify them as curves. Alternatively, for example, if the angle formed by the line connecting the vertices on the curved line (e.g., 160 degrees) is greater than a predetermined threshold value (e.g., 160 degrees) and the distance to the corresponding edge is less than a threshold value (e.g., 2.5 m (the third threshold value)), the system can automatically determine that the section is a curved line and exclude isolated vertices on the curved line from being designated as isolated vertices. In this case, the conditions for excluding isolated vertices from the isolated vertices can be further limited by adding a condition where the length of the edge before and after the isolated vertex is shorter than a predetermined threshold value (e.g., 2 m). This allows for more accurate identification of isolated vertices on the curved line. This allows for accurate elimination of isolated vertices, particularly when the curve has a large number of vertices.

[0049] Fig. 6 is a flow diagram showing an example of the operation of the map evaluation device 100 according to the embodiment. In Fig. 6, map information stored in advance in a server provided in a legal affairs bureau, a city, town, or village, or in a USB or other appropriate storage medium, is acquired via the communication unit 22 and stored in the storage unit 26 (S1).

[0050] The stroke designation unit 10 designates a stroke to be compared on a first map, such as a Legal Affairs Bureau official map, and a second map, such as a current land lot map, included in the map information, based on instruction information input by the user via the input unit 28, and stores the designation in the memory unit 26 (S2).

[0051] The contour coordinate value extraction unit 12 reads out the map information and the information of the parcel to be compared stored in the storage unit 26, and extracts a first contour from the first map and a second contour from the second map as the contours of the parcels, as the coordinate values ​​of the vertices that define each contour. The coordinate values ​​of the vertices that define the extracted first contour and second contour are stored in the storage unit 26 as a set of the first contour and second contour of the same parcel for each parcel to be compared (S3).

[0052] The conversion unit 14 reads information about the first and second maps from the storage unit 26 and determines whether the coordinate systems of the first and second maps are different (S4). If it is determined in S4 that the coordinate systems are different (N), the following coordinate value conversion process is performed. This conversion process first unifies the vertices defining the first outline and the vertices defining the second outline into one or another coordinate system. Next, the coordinate values ​​of the points on one or both of the first and second outlines of the comparison brush are converted by moving, rotating, enlarging, or reducing them so that the distance between the vertices defining the first outline and the vertices defining the second outline is minimized, and the conversion process is performed so that one or both of the first and second outlines whose coordinate values ​​have been converted before and after the conversion maintain similar shapes. The coordinate values ​​after the conversion process are stored in the storage unit 26 (S5).

[0053] The matching processor 20 reads the coordinate values ​​of the vertices defining the first and second outer shapes from the storage unit 26, and determines pairs of corresponding vertices between the first and second outer shapes based on the read coordinate values. If corresponding vertices cannot be determined between the first and second outer shapes, the matching processor 20 determines those vertices as isolated vertices. Information about the determined pairs of vertices is stored in the storage unit 26 along with the coordinate values ​​of each vertex, either as information identifying the corresponding vertex of the other outer shape or as information indicating whether or not there is an isolated vertex (S6). Here, the coordinate values ​​of the vertices defining the first and second outer shapes used in S6 are the coordinate values ​​after the conversion process in S5 if it is determined in S4 that the coordinate systems are different (N), and are the coordinate values ​​not subjected to the conversion process by the converter 14 if it is determined in S4 that the coordinate systems are not different (Y).

[0054] The evaluation data generation unit 16 reads from the memory unit 26 the coordinate values ​​of the vertices that define the first outer shape and the vertices that define the second outer shape, which are stored as a pair, and the coordinate values ​​of the vertices that have been determined to be isolated vertices, and generates evaluation data based on the read coordinate values ​​and stores the data in the memory unit 26 (S7).

[0055] The evaluation unit 18 reads out the evaluation data generated by the evaluation data generation unit 16 in S7 from the memory unit 26, evaluates the difference between the first and second outer shapes of the same blocks on the first and second maps from the evaluation data, and stores the evaluation data in the memory unit 26 (S8).

[0056] After evaluation of all target parcels is completed, the display control unit 24 reads the evaluation results for each parcel evaluated in S8 from the memory unit 26 and controls an LCD display or other appropriate display device to display the evaluation results (S9). For example, if there is a significant difference in shape between the first and second maps, the outline of each parcel on the current parcel number status map is displayed in a different color according to the evaluation results. By displaying problem areas in color, workers can visually identify problem areas on the current parcel number status map, thereby enabling efficient correction work on the current parcel number status map. Furthermore, evaluation results aggregated by block, official map, town, and district, etc., may be displayed by coloring the corresponding area on the map for each aggregation unit. This makes it possible to identify regional problem areas and use them as an indicator for determining the priority of correction work.

[0057] The program for executing each step of Fig. 6 can be stored in a recording medium, or the program can be provided via a communication means. In such a case, for example, the program described above can be considered as an invention of a "computer-readable recording medium on which a program is recorded" or an invention of a "data signal."

[0058] As explained above, according to the present invention, it is possible to verify the consistency between the official map of the Legal Affairs Bureau and the current parcel number map based on objective indicators. It is also possible to visually confirm the consistency.

[0059] In addition, when checking land boundaries, the consistency of the shape of the land (plot) is evaluated from the perspective that the stakes indicating the land boundaries are the vertices of the outline, and by focusing in particular on evaluating whether there are any excess or deficiencies in the stakes (presence or absence of isolated vertices), this contributes to improving the credibility of the verification results.

[0060] Conversely, in particular in areas where the boundaries of a plot are curved, by not recognizing the vertices that define the shape of the curve as isolated vertices, it is possible to properly evaluate the differences between the Legal Affairs Bureau official map and the current land number map.

[0061] In this way, by referring to the evaluation results of the present invention, it is possible to efficiently verify and correct the current land lot map, thereby realizing appropriate fixed asset tax levy. [Explanation of symbols]

[0062] 10 stroke designation unit, 12 outer coordinate value extraction unit, 14 conversion unit, 16 evaluation data generation unit, 18 evaluation unit, 20 matching processing unit, 22 communication unit, 24 display control unit, 26 storage unit, 28 input unit, 30 CPU, map evaluation device 100.

Claims

1. A map evaluation device that evaluates a difference between a first map and a second map, each of which represents a stroke shape, comprising: a stroke designation unit for designating strokes to be compared on the first map and the second map; an outline coordinate value extraction unit that extracts a first outline from the first map and a second outline from the second map as the outlines of strokes to be compared that are designated by the stroke designation unit, as coordinate values ​​of vertices that define each outline; a matching processing unit that determines a pair of corresponding vertices between the first outer shape and the second outer shape based on the coordinate values, and determines whether there is an isolated vertex for which a corresponding vertex cannot be determined; an evaluation data generation unit that generates evaluation data based on the set of vertices and the presence or absence of an isolated vertex; an evaluation unit that evaluates a difference between the first map and the second map based on the evaluation data; A map evaluation device comprising:

2. 2. The map evaluation device according to claim 1, wherein the evaluation unit evaluates the differences between the first map and the second map based on the distances between vertices in the sets of vertices generated by the evaluation data generation unit and the presence or absence of isolated vertices.

3. 3. The map evaluation device according to claim 2, wherein the evaluation unit is capable of changing weightings for evaluation of the distance between the vertices in the set of vertices and the presence or absence of the isolated vertex.

4. 4. The map evaluation device according to claim 1, wherein the evaluation data generation unit excludes each of the isolated vertices from being designated as an isolated vertex when the isolated vertex exists, the shortest distance from the isolated vertex to the first outline or the second outline that does not include the isolated vertex is equal to or less than a predetermined threshold, and an interior angle at each of the isolated vertices is equal to or greater than a predetermined threshold.

5. a conversion unit that converts the coordinate values ​​of one or both vertices of the outline of the brush to be compared so that the distance between the vertices that define the first outline and the vertices that define the second outline is minimized when the coordinate systems of the first map and the second map are different, and converts the coordinate values ​​of the first outline and / or the second outline to maintain similar shapes before and after the conversion; The map evaluation device according to claim 1 , wherein the matching processing unit determines the pair of vertices and whether or not there is an isolated vertex based on the transformed coordinate values.

6. A map evaluation method for evaluating differences between a first map and a second map, each map representing a stroke shape, comprising: a step of designating plots to be compared on the first map and the second map; extracting a first outline from the first map and a second outline from the second map as the outlines of the designated brush strokes to be compared, as coordinate values ​​of vertices defining each outline; determining a pair of corresponding vertices between the first and second outer shapes based on the coordinate values, and determining whether there is an isolated vertex for which a corresponding vertex cannot be determined; generating evaluation data based on the set of vertices and the presence or absence of isolated vertices; evaluating a difference between the first map and the second map from the evaluation data; A map evaluation method comprising:

7. Computer, a stroke designation unit for designating a stroke to be compared in the first map and the second map representing the stroke shape; an outline coordinate value extraction unit that extracts a first outline from the first map and a second outline from the second map as the outlines of strokes to be compared that have been designated by the stroke designation unit, as coordinate values ​​of vertices that define each outline; a matching processing unit that determines a pair of corresponding vertices between the first outer shape and the second outer shape based on the coordinate values, and determines whether there is an isolated vertex for which a corresponding vertex cannot be determined; an evaluation data generation unit that generates evaluation data based on the set of vertices and the presence or absence of an isolated vertex; an evaluation unit that evaluates a difference between the first map and the second map based on the evaluation data; A map evaluation program for evaluating a difference between a first map and a second map, characterized in that the program functions as follows.

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