Apparatus and method for creating a 3D fold diagram of the earth's surface

Abstract

To provide a ground surface three-dimensional folding chart creation device and a ground surface three-dimensional folding chart creation method which can easily create a three-dimensional folding chart of a ground surface for creating a three-dimensional map.SOLUTION: A ground surface image division unit 10 divides a ground surface image to generate a plurality of divided ground surface images. A height information acquisition unit 12 sets a height reference point on each side of the divided ground surface image. A side surface chart image generation unit 14 generates a polygonal side surface chart image with start and end points of each bottom side and a height reference point apex as apexes by setting the height reference point apex having the altitude of the height reference point for each position corresponding to the height reference point on the bottom side with the same length as each side of the divided ground surface image. An upper side chart image generation unit 16 generates an upper side chart image by extending the length of each side of the divided ground surface image so as to match the total sum of the lengths of line segments connecting the height reference point apex and expanding the divided ground surface image according to the extended length of each side. A three-dimensional folding chart data generation unit 18 generates three-dimensional folding chart data with which the side surface chart image and the upper side chart image can be printed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an apparatus for creating a three-dimensional fold diagram of a ground surface and a method for creating a three-dimensional fold diagram of a ground surface. [Background technology]

[0002] In recent years, with the advancement of digital technology, it has become common to view and manipulate geospatial information, such as two-dimensional or three-dimensional maps and elevation data, on a monitor, and there are increasing opportunities for general users to use it not only for business purposes but also for leisure activities such as playing games.

[0003] However, digital products require a PC, peripheral devices, and software, and are costly to create, including the setup of the environment; they require a certain level of knowledge about digital technology; and it is difficult to directly touch and experience the size and texture of the products.

[0004] Meanwhile, in order to intuitively understand the unevenness of the terrain, models that express the terrain three-dimensionally (stereoscopically) are also used, such as "diorama maps," "tactile maps," "3D maps," "laminated models," etc. (hereinafter collectively referred to as 3D maps). For example, Patent Document 1 below discloses a 3D model formed by laminating a plurality of contour pieces obtained by cutting a sheet body along contour lines drawn on it. Patent Document 2 below discloses a 3D map made of soft synthetic resin, which includes a 3D portion in which a predetermined terrain is 3D-formed and a flat portion in which a plurality of recesses are provided.

[0005] However, these three-dimensional maps had problems in that they required the purchase of specialized equipment such as 3D printers or the ordering of orders to specialized companies, and they were very expensive to create for a wide area or to mass-produce. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP Patent Publication No. 5-313584 [Patent Document 2] JP2020-27141 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide an apparatus and method for creating a three-dimensional fold diagram of the earth's surface, which can easily create a three-dimensional fold diagram of the earth's surface for creating a three-dimensional map. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention includes the following embodiments.

[0009] [1] A ground surface image division means for dividing a ground surface image, which is a two-dimensional image representing the ground surface, into a plurality of divided ground surface images of an arbitrary shape; a height information acquiring means for setting height reference points at a plurality of locations on each side of the divided ground surface image, including the start and end points of the side, and acquiring the height of the ground surface at each of the height reference points; a side view image generating means for setting a base having the same length as each side of the divided ground surface image, and for each position on each base corresponding to the height reference point, setting a height reference point vertex having a height corresponding to the height of the ground surface at the height reference point, and generating a polygonal side view image having vertices at the start and end points of each base and the height reference point vertex for each side of the divided ground surface image; a top view image generating means for extending a length of each side of the divided ground surface image so as to coincide with a total length of a line segment connecting the height reference point vertices of the side view corresponding to the side, and enlarging the divided ground surface image in accordance with the length of each extended side to generate a top view image; A three-dimensional fold data generating means for generating the side view image and the top view image as three-dimensional fold data which is printable output data; A device for creating three-dimensional folding diagrams of the earth's surface.

[0010] [2] The ground surface image division means divides the ground surface image into any triangles to generate multiple divided ground surface images, in the device for creating a three-dimensional folding diagram of the ground surface described in [1].

[0011] [3] A three-dimensional folding diagram creation device for the earth's surface described in [2], in which a triangular prism is formed by a side corresponding to the side view and a top surface corresponding to the top view by printing out the three-dimensional folding diagram data, and a three-dimensional map of the earth's surface is formed by one or more combinations of the triangular prisms.

[0012] [4] a ground surface image division step of dividing a ground surface image, which is a two-dimensional image representing the ground surface, into arbitrary shapes to generate a plurality of divided ground surface images; a height information acquisition step of setting height reference points at a plurality of locations on each side of the divided ground surface image, including the start and end points of the side, and acquiring the height of the ground surface at each of the height reference points; a side view image generating step of setting a base having the same length as each side of the divided ground surface image for each side, setting a height reference point vertex having a height corresponding to the height reference point on each base for each position corresponding to the height reference point on the ground surface, and generating a polygonal side view image having vertices at the start and end points of each base and the height reference point vertex for each side of the divided ground surface image; a top view image generating step of extending the length of each side of the divided ground surface image so as to coincide with the sum of the lengths of the line segments connecting the height reference point vertices of the side view corresponding to the side, and enlarging the divided ground surface image according to the length of each extended side to generate a top view image; a 3D fold data generating step of generating the side view image and the top view image as 3D fold data which is printable output data; A method for creating a three-dimensional folding diagram of the ground surface comprising the steps of: Effect of the Invention

[0013] According to the present invention, a device for creating a 3D fold diagram of the earth's surface and a method for creating a 3D fold diagram of the earth's surface can be provided, which can easily create a 3D fold diagram of the earth's surface for creating a three-dimensional map. [Brief description of the drawings]

[0014] [Figure 1] 1A and 1B are diagrams showing an example of a triangular prism formed by bonding together a top view and a side view according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of a three-dimensional map of the earth's surface formed by combining triangular prisms according to an embodiment. [Diagram 3] FIG. 1 is a functional block diagram of an example of a three-dimensional folding diagram creation device for a ground surface according to an embodiment. [Figure 4] 5 is an explanatory diagram of a process of generating a divided ground surface image by a ground surface image dividing unit according to the embodiment; FIG. [Diagram 5] 11 is an explanatory diagram of a setting process of a height reference point by a height information acquisition unit according to the embodiment. FIG. [Figure 6] 11A to 11C are explanatory diagrams of a side view image generating process performed by a side view image generating unit according to the embodiment. [Figure 7] 11A and 11B are explanatory diagrams of a process of a top view image generating unit according to the embodiment. [Figure 8] 11 is an explanatory diagram of a process of enlarging a divided ground surface image by a top view image generating unit according to the embodiment. FIG. [Figure 9] 11 is an explanatory diagram of a process in which a top view image generating unit according to an embodiment transforms a divided ground surface image before enlargement by using auxiliary lines. FIG. [Figure 10] FIG. 11 is a diagram showing an example of a printed result of the three-dimensional fold diagram data generated by the three-dimensional fold diagram data generating unit according to the embodiment. [Figure 11] FIG. 11 is a flow diagram of an example of the operation of the three-dimensional folding diagram creation device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, modes for carrying out the present invention (hereinafter, referred to as embodiments) will be described with reference to the drawings.

[0016] The earth's surface 3D folding diagram creation device 100 according to the embodiment is a device that allows a user to easily create a 3D map by printing a 3D folding diagram including a top view and a side view of the earth's surface for creating a 3D map using a printer or the like, and cutting and pasting the printed out printouts by himself / herself. The printed out printouts are cut out and pasted together to form a triangular prism or the like with a side surface corresponding to the side view and a top surface corresponding to the top view, and a 3D map of the earth's surface is formed by one or more combinations of the triangular prisms or the like. The top view is a diagram (image) in which contour lines or the like representing the elevation of the earth's surface are drawn and an image of the earth's surface that has been appropriately colored is appropriately divided, and the side view is a polygon representing the elevation of each side of the top view.

[0017] 1(a), (b), and (c) show examples of a triangular prism, including a top view, a side view, and a combination of the top view and side view. Fig. 1(a) shows an example of a top view, Fig. 1(b) shows an example of a side view, and Fig. 1(c) shows an example of a triangular prism.

[0018] The top view in Fig. 1(a) is an image (top view image) resulting from processing by a top view image generating unit 16, which will be described later, on a divided ground surface image obtained by dividing a ground surface image, which is a two-dimensional image showing the ground surface of a target area for creating a 3D map, into triangles by a ground surface image dividing unit 10, which will be described later. Note that, as will be described later, the divided ground surface image and the top view image generated from it are not limited to triangles and can be set arbitrarily.

[0019] 1(b) shows the top view image and side views corresponding to each side of the top view image. The corresponding relationship between each side and the side view is shown by a dashed line. The side view is an image (side view image) obtained as a result of executing processing of the side view image generating unit 14 described later on the divided ground surface image.

[0020] The triangular prism in FIG. 1(c) was created by printing the top view image and side view image on paper, cutting them out, and pasting them together.

[0021] Figures 2(a) and (b) show examples of a 3D map of the earth's surface formed by combining the above-mentioned triangular prisms. Figure 2(a) shows four triangular prisms created by printing out a top view image generated from a divided earth's surface image obtained by dividing a nearly square earth's surface image into four triangular regions, and side view images corresponding to each side of the four divided earth's surface images. Figure 2(b) shows a 3D map of the earth's surface formed by bringing these triangular prisms into contact with each other at the side surfaces corresponding to the mutually matching sides of the divided earth's surface image (sides generated by dividing along the same dividing line, which will be described later).

[0022] FIG. 3 shows a functional block diagram of an example of the 3D fold diagram creation device 100 for the ground surface according to the embodiment. In FIG. 3, the 3D fold diagram creation device 100 for the ground surface includes a ground surface image division unit 10, a height information acquisition unit 12, a side view image generation unit 14, a top view image generation unit 16, a 3D fold diagram data generation unit 18, a display control unit 20, a communication unit 22, a storage unit 24, and a CPU 26. In addition to the CPU 26, an accelerator such as a GPU may be used. The 3D fold diagram creation device 100 for the ground surface includes the CPU 26, a ROM, a RAM, a non-volatile memory, an I / O, a communication interface, and the like, and is configured as a computer that controls the entire device and performs various calculations, and each of the above functions is realized, for example, by the CPU 26 and a program that controls the processing operation of the CPU 26.

[0023] The ground surface image division unit 10 acquires a ground surface image, which is a two-dimensional image representing the ground surface of a target area for which a three-dimensional map is to be created, and divides the acquired ground surface image into an arbitrary shape by generating division lines on the ground surface image, thereby generating a plurality of divided ground surface images. In this case, the shape of the divided ground surface image, i.e., the shape when dividing the ground surface image, is arbitrary and is not particularly limited, but a shape surrounded by straight sides is preferable, and a triangle is more preferable, because it allows easy creation of a three-dimensional map. Note that the ground surface image and the divided ground surface images obtained by dividing it have coordinate information of each point in the image. When dividing the ground surface image, the ground surface image division unit 10 generates division lines on the ground surface image, but in this case, vertices are generated on the ground surface image, and the division lines are generated as lines connecting each vertex. The position of the vertex may be any point other than the center of the ground surface image, but it is preferable to include the highest or lowest point of elevation in the target area, since this makes it easier to create a three-dimensional map. For this reason, the ground surface image division unit 10 is configured to acquire elevation data of the target area. In this case, it is preferable to divide the target area into an equally spaced grid shape and acquire elevation data for each grid (digital elevation model: DEM). Alternatively, the elevation of the target area may be acquired by a user reading the contour lines and elevation points on a topographical map and inputting the data using an appropriate input means such as a keyboard, a pointing device such as a mouse, or a touch panel. Note that the user may be able to add or delete division lines using the appropriate input means according to the topography of the target area. Details of the processing by the earth's surface image division unit 10 will be described later.

[0024] The ground surface image is typically a topographical map of the target area, but other images may be house maps, road maps, aerial photographs, satellite photographs, various thematic maps with colored topography, etc. The ground surface image data and elevation data may be acquired from an external server or the like via the communication unit 22. Alternatively, the data may be read from a USB memory or other storage means, or may be acquired by the user inputting the data via the appropriate input means.

[0025] The data of the ground surface image, the elevation data, the dividing line data, and the divided ground surface image data (including the edge data) are stored in the storage unit 24 by the ground surface image dividing unit 10.

[0026] The height information acquisition unit 12 reads out the divided ground surface image and the elevation data obtained by dividing the ground surface image by the dividing line generated by the ground surface image division unit 10 from the storage unit 24, sets height reference points at a plurality of locations on each side of the divided ground surface image, including the start and end points of the side, and acquires the ground surface height (altitude) of each of the height reference points. The height reference points may be set at a predetermined interval on each side of the divided ground surface image, or may be set at an arbitrary interval. In these cases, it is preferable that the user sets the height reference points using the appropriate input means. In addition, when setting the height reference points at an arbitrary interval, the interval of the height reference points may be changed according to the topography represented by the divided ground surface image. The height information (altitude) of the height reference points can be acquired from the elevation data, for example, by superimposing the height reference points and the elevation data (DEM data) based on the coordinate information that each of them has. In addition, the user may acquire the elevation of the height reference points by reading the contour lines and elevation points of a topographical map and inputting them using the appropriate input means. The process performed by the height information acquisition unit 12 will be described in detail later.

[0027] The height information acquiring unit 12 stores in the storage unit 24 the coordinate information (position data) and height information (height data) of the height reference point set as described above.

[0028] The side view image generating unit 14 generates the side view image shown in FIG. 1(b) and the like by the following process. Here, as shown in FIG. 1(b), the side view image is a polygon surrounded by a broken line connecting a base and a point (a height reference point vertex to be described later) representing the altitude of a specific point on each side of the divided ground surface image, and a line connecting both ends of the base and both ends of the broken line. The side view image generating unit 14 reads out the data of the divided ground surface image, the position data of the height reference point, and the height data from the storage unit 24, and sets a base having the same length as each side of the divided ground surface image for each side, and sets a height reference point vertex having a height according to the height (altitude) of the ground surface of the height reference point for each position on each base. The process of setting a base having the same length as each side can be executed, for example, by generating a bottom image having the same shape and perimeter length as the divided ground surface image, and setting the corresponding side of this bottom image as the base. Furthermore, the positions on each base side corresponding to the height reference point are determined by calculating the distance from the end of each side to each height reference point, and are determined as positions at the same distance from the end of each base side corresponding to each side. Next, side view images of polygons having the start and end points of each base side and the height reference point vertices are generated for each side of the divided ground surface image. Data of the generated side view images is stored in storage unit 24 by side view image generation unit 14. Details of the processing by side view image generation unit 14 will be described later.

[0029] The top view image generating unit 16 reads out the data of the divided ground surface image and the data of the side view image from the storage unit 24, extends the length of each side of the divided ground surface image so that it coincides with the total length of the line segments connecting the height reference point vertices of the side view image corresponding to the side, and enlarges the divided ground surface image according to the length of each extended side to generate a top view image. The data of the top view image obtained by enlarging the divided ground surface image is stored in the storage unit 24 by the top view image generating unit 16. Details of the processing of the top view image generating unit 16 will be described later.

[0030] The 3D fold diagram data generating unit 18 reads out the side view image data and the top view image data from the storage unit 24, and generates the side view image and the top view image as 3D fold diagram data, which is printable output data. The 3D fold diagram data generating unit 18 stores the generated 3D fold diagram data in the storage unit 24.

[0031] The display control unit 20 reads out the ground surface image data, dividing line data, divided ground surface image data, side view image data, top view image data, and three-dimensional folded drawing data, etc. from the memory unit 24, and controls an LCD display device or other appropriate display device to display them.

[0032] The communication unit 22 is configured with an appropriate interface, and executes processes such as acquiring data of the ground surface image from an external server or the like, and passing it to the ground surface image division unit 10 .

[0033] The storage unit 24 is composed of a non-volatile memory such as a hard disk drive or a solid state drive (SSD), and stores the above-mentioned various information and the operation program of the CPU 26, and other information necessary for each process performed by the 3D folding diagram creation device 100 for the earth's surface. The storage unit 24 may be a digital versatile disk (DVD), a compact disk (CD), a magneto-optical disk (MO), a flexible disk (FD), a magnetic tape, an electrically erasable and rewritable read-only memory (EEPROM), a flash memory, or the like. The storage unit 24 preferably includes a random access memory (RAM) that mainly functions as a working area for the CPU 26, and a read-only memory (ROM) in which control programs such as the BIOS and other data used by the CPU 26 are stored.

[0034] 4(a) and (b) show explanatory diagrams of the generation process of the divided ground surface image by the ground surface image division unit 10. Fig. 4(a) is an example of the ground surface image of the target area. As described above, the ground surface image is a two-dimensional image representing the ground surface of the target area acquired by the ground surface image division unit 10.

[0035] As shown in FIG. 4(b), the ground surface image dividing unit 10 divides the ground surface image by a dividing line D L In the example of Fig. 4(b), the dividing line D is the perimeter of a square, its diagonal, and the lines connecting the midpoints of the sides. L As a result, the ground surface image is divided into eight triangles, and each triangular area becomes a divided ground surface image as shown in FIG. 4(b).

[0036] 5 is an explanatory diagram of a setting process of a height reference point by the height information acquisition unit 12. In FIG. 5, the height information acquisition unit 12 uses the division line D generated on the ground surface image by the ground surface image division unit 10. L As described above, the height reference points Hp may be set at a predetermined interval or at any interval. L It is preferable to display the generated ground surface image on an appropriate display device, and the user sets the height reference points Hp by using the appropriate input means while viewing the image. In this case, the interval between the height reference points Hp may be changed according to the topography, etc., represented by the divided ground surface image.

[0037] Next, the height information acquisition unit 12 superimposes the height reference point Hp and the above-mentioned elevation data (DEM data) based on the coordinate information that each of them has, thereby acquiring information on the height of the height reference point Hp from the elevation data.

[0038] It is preferable to set the highest point and the lowest point of the elevation on each side of the divided ground surface image as the height reference points. This is because the created three-dimensional map can more accurately represent the topography. In this case, the height information acquisition unit 12 extracts the highest point and the lowest point of the elevation from the coordinate information of each point on the side of the divided ground surface image based on the coordinate information of the elevation data (DEM data) read from the storage unit 24. The height information acquisition unit 12 may also add a height reference point at a location where the slope changes significantly between the highest point and the lowest point of the elevation. Here, whether or not the slope changes significantly is determined based on a linear equation representing the height of a line segment connecting two adjacent height reference points, and if the absolute value of the difference between the elevation of a point on the side of the divided ground surface image and the height based on the linear equation exceeds a predetermined threshold, the slope changes significantly. The threshold is appropriately determined depending on the scale and the required accuracy. The process of adding the height reference point may be configured to be executed based on an instruction input by the user through the appropriate input means. In addition, the dividing line D is a line on a flat place or a constant slope where there is no change in slope along the way, or where the change is small as judged in the same manner as above. L There is no need to set a height reference point in the middle at the top.

[0039] 6(a), (b), and (c) are diagrams illustrating the generation process of the side view image by the side view image generating unit 14. FIG. 6(a) shows that, in the example shown in FIG. 4(b) and FIG. 5, eight triangular regions generated as the divided ground surface image are joined in pairs of adjacent two to form four triangular regions (regions 1 to 4). These four regions 1 to 4 are also divided ground surface images. Note that this joining process can be configured to be executed by the ground surface image dividing unit 10 or the side view image generating unit 14 based on an instruction input by the user via the appropriate input means, for example.

[0040] Figures 6(b) and (c) are explanatory diagrams of the generation process of a side view image for region 3 in Figure 6(a). Figure 6(b) shows a triangle indicating region 3, and its three sides are indicated by A, B, and C. Height reference points Hp set by height information acquisition unit 12 are indicated on these sides A, B, and C. For the sake of later explanation, the height reference points set on side A are numbered Hp1 to Hp6 in order.

[0041] As shown in Fig. 6(c), the side view image generating unit 14 sets a base Lb having the same length as the three sides A, B, and C of the area 3, which is the divided ground surface image. This base Lb has a one-to-one correspondence with each point of the three sides A, B, and C, and has points corresponding to the 20 height reference points Hp set on the sides A, B, and C. In Fig. 6(c), A, B, and C are written in the range of the base Lb corresponding to the sides A, B, and C, respectively.

[0042] Next, the side view image generating unit 14 sets a height reference point vertex Ht having a height corresponding to the height (altitude) of the ground surface of the height reference point Hp for each position corresponding to the height reference point on the base side Lb. The height reference point vertex Ht is set on a perpendicular line erected from the height reference point Hp on the base side Lb. The side view image generating unit 14 creates a side view image Sv having a continuous trapezoidal shape by connecting the set height reference point vertices Ht in order. In FIG. 6(c), 20 trapezoids Tr1 to Tr20 corresponding to the 20 height reference points Hp set on the sides A, B, and C are created. The correspondence relationship between the side view image Sv composed of these multiple trapezoids Tr1 to Tr20 and the sides A, B, and C of the triangular area (area 3) which is the divided ground surface image is shown by writing A, B, and C in the corresponding ranges of the base side Lb, respectively, as described above.

[0043] In the above example, the elevation of the ground surface is used as the height of each height reference point Hp, but the height may be weighted and emphasized. For example, the actual elevation may be multiplied by n (×n, n is a real number). Furthermore, the reference elevation of each height reference point Hp does not necessarily have to be set to 0 m as the elevation of the base Lb, and an appropriate reference elevation may be determined and only the difference between the elevations may be used as the side view image. Furthermore, if there is information for the side view image (geological map, underground resources, underground structures, etc.), it may be pasted onto the side view image.

[0044] FIG. 7 illustrates an explanatory diagram of the process of the top view image generating unit 16. The example illustrated in FIG. 7 corresponds to the side A illustrated in FIG. 6(b). In FIG. 6(b), the height reference points set on the side A are numbered Hp1 to Hp6 in order from the upper right to the lower left of the side A, and in FIG. 7, the points on the base side Lb corresponding to the height reference points Hp1 to Hp6 are numbered Hp1 to Hp6 in order. In addition, the height reference point vertices having the heights of the height reference points Hp1 to Hp6 are also numbered Ht1 to Ht6, and the heights of the height reference points Hp1 to Hp6 from the base side Lb (the lengths between the corresponding height reference points Hp1 to Hp6 and the height reference point vertices Ht1 to Ht6) are represented by H1 to H6.

[0045] Here, the distances between adjacent height reference points Hp on the base side Lb (the same as the distances between adjacent height reference points Hp on side A) are sequentially designated as BL1 to BL5, and the distances between adjacent height reference point vertices Ht1 to Ht6 are sequentially designated as L1 to L5. Note that L1 to L5 are the lengths of the slopes connecting the height reference point vertices Ht1 to Ht6.

[0046] The distances L1 to L5 between the adjacent height reference point vertices Ht1 to Ht6 are calculated as follows. L n =√((H n+1 -H n ) 2 +BL n 2 )

[0047] Next, the top view image generating unit 16 calculates the sum of the distances L1 to L5 between the height reference point vertices Ht1 to Ht6 (ΣLn ) and calculate the length of side A by the sum of the above distances (ΣL n ) is extended to match the edge A. This process is also performed on the other sides B and C, and the end points of the extended sides A, B, and C (the end points that were joined before the extension) are joined together, and the triangle representing area 3 as the divided ground surface image is enlarged according to the lengths of the extended sides A, B, and C to obtain the enlarged area. The same process is performed on the other areas 1, 2, and 4 to obtain the enlarged areas of each.

[0048] 8(a) and (b) are explanatory diagrams of the process of enlarging the divided ground surface image by the top view image generating unit 16. Fig. 8(a) shows the divided ground surface image ID1 before enlargement and the contour line Lp of the divided ground surface image after enlargement. The contour line Lp of the divided ground surface image after enlargement is the contour of the enlarged area obtained by the process of Fig. 7.

[0049] Next, as shown in Figure 8(b), the top view image generation unit 16 performs an affine transformation on the divided ground surface image ID1 before enlargement, deforming the size of the image, i.e., the shape of the image contour, so that it matches the above-mentioned enlarged area (contour line Lp of the enlarged divided ground surface image), to generate the enlarged divided ground surface image, i.e., the top view image ID2.

[0050] 9(a) and (b) are explanatory diagrams of the process in which the top view image generating unit 16 uses auxiliary lines to deform the divided ground surface image before enlargement. In FIG. 9(a), similarly to FIG. 8(a), the divided ground surface image ID1 before enlargement and the contour line Lp of the divided ground surface image after enlargement are shown. The contour line Lp of the divided ground surface image after enlargement is obtained by the process of enlarging the divided ground surface image by the top view image generating unit 16, as explained in FIG. 8(a) and (b) above.

[0051] Here, in the divided ground surface image ID1 before enlargement, if there is a large change in the topography, such as elevation difference, a height auxiliary line La is drawn from one of the vertices (indicated by V in FIG. 9(a)) toward the height reference point of the opposing side (preferably the highest point or the lowest point). The process of drawing the height auxiliary line La is executed by the ground surface image division unit 10 based on auxiliary line creation instruction information input by the user by specifying the vertex V and the height reference point of the opposing side by the appropriate input means. Note that multiple height auxiliary lines La may be set according to the topography.

[0052] Next, the height information acquisition unit 12 places a height reference point Hp on the height extension line La and acquires height information of the height reference point Hp. The side view image generation unit 14 sets a height reference point vertex Ht according to the altitude of the height reference point Hp, and the top view image generation unit 16 determines the distance between the height reference point vertices Ht and extends the height extension line La.

[0053] As a result of extending the height auxiliary line La, as shown in Fig. 9(b), the contour line Lp of the enlarged divided ground surface image becomes a broken line at the position of the height reference point where the height auxiliary line La is joined. The top view image generating unit 16 performs an affine transformation on the divided ground surface image ID1 before enlargement based on the contour line Lp of the enlarged divided ground surface image including the broken line shown in Fig. 9(b), and transforms the size of the image, i.e., the shape of the contour of the image, so as to match the enlarged area, to generate a top view image ID2.

[0054] 10(a) and (b) show examples of the print results of the 3D fold diagram data generated by the 3D fold diagram data generating unit 18. Fig. 10(a) includes the print results of the top view image ID2 and the side view image Sv that constitute the 3D fold diagram data.

[0055] As shown in Fig. 10(b), the 3D fold diagram data generating unit 18 provides an appropriate overlap area Ov around the top view image ID2 and the side view image Sv, and prints out the top view image ID2 and the side view image Sv in a linked state. This makes it possible to easily create a 3D fold diagram (3D map) as shown in Fig. 2(b) by cutting out the printed out top view and side view and pasting them together with the overlap area Ov.

[0056] Fig. 11 shows a flow diagram of an example of the operation of the 3D folding diagram creation device 100 according to the embodiment. In Fig. 11, the ground surface image division unit 10 acquires ground surface image data and elevation data (S1), generates division lines on the ground surface image to divide it, and generates a plurality of divided ground surface images (S2).

[0057] The height information acquisition unit 12 sets height reference points at multiple locations on each side of the divided ground surface image, including the start and end points of the side (S3), and acquires the ground surface height (altitude) of each of the height reference points (S4).

[0058] The side view image generating unit 14 sets a base having the same length as each side of the divided ground surface image, and sets a height reference point vertex having a height corresponding to the height reference point on each base at a position corresponding to the height reference point on the ground surface (altitude) of the height reference point (S5). Next, the side view image generating unit 14 generates a polygonal side view image having vertices at the start and end points of each base and the height reference point vertex for each side of the divided ground surface image (S6).

[0059] The top view image generating unit 16 extends the length of each side of the divided ground surface image so that it matches the sum of the lengths of the line segments connecting the height reference point vertices of the side view corresponding to that side (S7), and enlarges the divided ground surface image according to the length of each extended side to generate a top view image (S8).

[0060] The 3D fold diagram data generating unit 18 generates the side view image and the top view image as 3D fold diagram data, which is printable output data (S9).

[0061] By printing out the 3D folding diagram data, a printout is obtained on which a top view and a side view for creating a 3D map are printed. If the divided ground surface image is a triangle, a triangular prism is formed by the side corresponding to the side view and the top surface corresponding to the top view, and a 3D map of the ground surface is formed by one or more combinations of the triangular prisms. If the top view image is a polygon other than a triangle, a 3D map of the ground surface is formed by one or more combinations of prisms having a base of the polygon. In this case, the combination may include a prism having a base of the polygon and a triangular prism.

[0062] The program for executing each step in Fig. 11 may be stored in a recording medium, or the program may be provided by a communication means. In that case, for example, the above-described program may be regarded as an invention of a "computer-readable recording medium on which a program is recorded" or an invention of a "data signal." [Explanation of symbols]

[0063] 10 ground surface image division unit, 12 height information acquisition unit, 14 side view image generation unit, 16 top view image generation unit, 18 3D folding diagram data generation unit, 20 display control unit, 22 communication unit, 24 memory unit, 26 CPU, 100 3D folding diagram creation device.

Claims

1. a ground surface image division means for dividing a ground surface image, which is a two-dimensional image representing the ground surface, into a plurality of divided ground surface images of an arbitrary shape; a height information acquiring means for setting height reference points at a plurality of locations on each side of the divided ground surface image, including the start and end points of the side, and acquiring the height of the ground surface at each of the height reference points; a side view image generating means for setting a base having the same length as each side of the divided ground surface image, and for each position on each base corresponding to the height reference point, setting a height reference point vertex having a height corresponding to the height of the ground surface at the height reference point, and generating a polygonal side view image having vertices at the start and end points of each base and the height reference point vertex for each side of the divided ground surface image; a top view image generating means for extending a length of each side of the divided ground surface image so as to coincide with a total length of a line segment connecting the height reference point vertices of the side view corresponding to the side, and enlarging the divided ground surface image in accordance with the length of each extended side to generate a top view image; a 3D fold data generating means for generating the side view image and the top view image as 3D fold data which is printable output data; A device for creating three-dimensional folding diagrams of the earth's surface.

2. 2. The device for creating a three-dimensional folding diagram of the earth's surface according to claim 1, wherein the ground surface image dividing means divides the ground surface image into any number of triangles to generate a plurality of divided ground surface images.

3. 3. The device for creating a 3D folding diagram of the earth's surface as described in claim 2, wherein a triangular prism is formed by a side surface corresponding to the side view and a top surface corresponding to the top view on a printed matter obtained by printing out the 3D folding diagram data, and a 3D map of the earth's surface is formed by one or more combinations of the triangular prisms.

4. a ground surface image division step of dividing a ground surface image, which is a two-dimensional image representing the ground surface, into a plurality of divided ground surface images of an arbitrary shape; a height information acquisition step of setting height reference points at a plurality of locations on each side of the divided ground surface image, including the start and end points of the side, and acquiring the height of the ground surface at each of the height reference points; a side view image generating step of setting a base having the same length as each side of the divided ground surface image, and setting a height reference point vertex having a height corresponding to the height reference point on each base at a position corresponding to the height reference point on the ground surface, and generating a polygonal side view image having vertices at the start and end points of each base and the height reference point vertex for each side of the divided ground surface image; a top view image generating step of extending the length of each side of the divided ground surface image so as to coincide with the sum of the lengths of the line segments connecting the height reference point vertices of the side view corresponding to the side, and enlarging the divided ground surface image according to the length of each extended side to generate a top view image; a 3D fold data generating step of generating the side view image and the top view image as 3D fold data which is printable output data; A method for creating a three-dimensional folding diagram of the ground surface comprising the steps of:

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