Drawing processing apparatus, drawing processing method, and program

Abstract

To easily simplify a building drawing.SOLUTION: A control part of an information processor detects two line segments which are in the same direction and whose interval is less than a prescribed value as a pair of line segments showing a wall of a building among line segments drawn on a building drawing (step S76). Then, the control part generates a grid composed of block line segments passing through the almost middle of the pair line segments (step S78). The control part deletes a part not overlapped with a pair line segment showing the wall of the building among block line segments constituting the grid, and generates a wall line being the block line segment showing the wall of the building, and makes the line segment showing the wall of the building into a single line (step S80).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a drawing processing device, a drawing processing method, and a program, and more particularly to a drawing processing device, a drawing processing method, and a program that can easily simplify building drawings. [Background technology]

[0002] The applicant has invented an image processing system that can accurately calculate the quantity of equipment on design drawings (see, for example, Patent Document 1). When submitting a waterworks application, a simple floor plan may be required for the building framework drawing used in the piping diagram. There was a problem in that it took a long time to create a floor plan by tracing the framework from a complex drawing such as a design drawing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6775624 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made to solve the above-mentioned problems, and aims to provide a drawing processing device, a drawing processing method, and a program that can easily simplify building drawings. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, a drawing processing device according to a first aspect of the present invention comprises a pair detection means for detecting a pair of first line segments representing the walls of a building from among the first line segments drawn on a building drawing, and a single-tracking means for single-tracking the lines representing the walls of a building by generating a second line segment that passes approximately midway between the pair of first line segments detected by the pair detection means.

[0006] In the above-mentioned drawing processing device, the pair detection means may detect two of the first line segments drawn on the building drawing that are in the same direction and have a distance between them that is less than a predetermined threshold value as a pair of first line segments that indicate walls of the building.

[0007] In the above-mentioned drawing processing device, the single-line conversion means may generate a grid consisting of the second line segments, delete the portions of the second line segments that constitute the grid that do not overlap with the pair of first line segments that represent the walls of the building, and generate the second line segments that represent the walls of the building, thereby single-lining the lines that represent the walls of the building.

[0008] The drawing processing device may further include a symbol extraction means for extracting symbols indicating equipment from the image of the building drawing, and a single-line drawing generation means for generating a single-line drawing in which the lines indicating the walls of the building are single-lined using the second line segments indicating the walls of the building generated by the single-line extraction means and the symbols indicating the equipment extracted by the symbol extraction means.

[0009] In the above-mentioned drawing processing device, the symbol extraction means may extract symbols indicating the equipment from the building drawing image by moving divided images that are smaller than the building drawing image on the building drawing image, and extracting only symbols that are entirely contained within the divided images, without extracting symbols that are only partially contained within the divided images, and when the same symbol is extracted twice in two consecutive divided images, it may be counted as one symbol.

[0010] In the above-mentioned drawing processing device, the symbol extraction means may use learning data obtained by machine learning images of symbols indicating the equipment to extract symbols indicating the equipment from the images of the architectural drawings.

[0011] In order to achieve the above-mentioned object, a drawing processing method according to a second aspect of the present invention comprises a pair detection step of detecting pairs of first line segments representing building walls from among the first line segments drawn on a building drawing, and a single-tracking step of single-tracking the lines representing the building walls by generating second line segments that pass approximately midway between the pairs of first line segments detected by the pair detection step.

[0012] In order to achieve the above-mentioned object, a program according to a third aspect of the present invention causes a computer to execute a pair detection procedure for detecting pairs of first line segments representing building walls from among the first line segments drawn on a building drawing, and a single-tracking procedure for single-tracking the lines representing the building walls by generating second line segments that pass approximately midway between the pairs of first line segments detected by the pair detection procedure. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a drawing processing device, a drawing processing method, and a program that can easily simplify building drawings. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram illustrating an example of the configuration of an information processing device. [Figure 2] FIG. 10 is a diagram showing a display example of a pre-processing screen. [Figure 3] FIG. 10 is a diagram showing a display example of a post-processing screen. [Figure 4] FIG. 10 is a diagram illustrating the single-tracking process; [Figure 5] FIG. 10 is a diagram illustrating the single-tracking process; [Figure 6] FIG. 10 is an explanatory diagram illustrating an example of picking out symbols indicating facilities. [Figure 7] 10 is a flowchart illustrating an example of a single-track process. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described.

[0016] First, the configuration of an information processing apparatus (drawing processing apparatus) according to an embodiment of the present invention will be described with reference to the drawings.

[0017] The information processing device of this embodiment analyzes vector data of building drawings read from external files, etc., collects line data that is thought to represent the walls of the building, and performs single-line processing of the structural body data while recognizing fixtures and fittings.

[0018] The information processing device 1 is configured, for example, by a general-purpose personal computer or the like, and is operated by a user. Note that the information processing device 1 may be any device that can be operated by a user, and may be configured, for example, by a general-purpose smartphone, tablet computer, or the like.

[0019] FIG. 1 is a block diagram showing an example of the configuration of an information processing device.

[0020] As shown in FIG. 1, the information processing device 1 includes a storage unit 11, a display unit 12, an operation unit 13, and a control unit 14, which are connected via a bus or the like.

[0021] The storage unit 11 is configured with a general-purpose storage device such as a hard disk drive. In this embodiment, the storage unit 11 stores building plan data indicating building plans read from an external file, for example. The storage unit 11 also stores various programs such as a single-tracking program 110.

[0022] The single-tracking program 110 is for executing a single-tracking process that single-tracks line segments representing building walls depicted on a building plan to generate a single-tracked plan. In this embodiment, the single-tracking program 110 includes a software library for use in machine learning and a framework for detecting objects in an image using the software library. An example of a software library for use in machine learning is TensorFlow, but any other software that can be used for machine learning may be used. An example of a framework is TensorFlow Object Detection API, but any other framework that can detect objects in an image may be used.

[0023] The display unit 12 is configured by, for example, a general-purpose liquid crystal display (LCD), etc. In this embodiment, the display unit 12 displays a pre-processing screen including a building plan based on the building plan data stored in the storage unit 11, a post-processing screen including a single-line drawing generated by single-line-changing the lines indicating the walls of the building drawn on the building plan, etc.

[0024] FIG. 2 is a diagram showing an example of a display of the pre-processing screen.

[0025] As shown in FIG. 2, the pre-processing screen 2 displays a building plan 21, a single-line instruction icon 22, and the like.

[0026] Building drawing 21 shows the "walls (structure) of the building," "fittings" such as interior doors and bathroom doors, and "equipment" such as sanitary equipment (washbasins, bathtubs, toilets, etc.) and kitchen equipment (sinks, stoves, etc.).

[0027] The single-line instruction icon 22 is used to instruct the generation of a single-line drawing in which the lines representing the walls of the building drawn in the building drawing 21 are single-lined, and is displayed as "single-line" in Figure 2.

[0028] FIG. 3 is a diagram showing a display example of the post-processing screen.

[0029] As shown in FIG. 3, the post-processing screen 3 displays a single-line drawing 31 and the like.

[0030] 1 is configured with, for example, a general-purpose keyboard, a mouse, etc., and is operated by a user. In this embodiment, the user operates the operation unit 13 to select a building drawing 21 to be displayed from among the building drawings 21 indicated by the building drawing data stored in the storage unit 11, or to click a single-line instruction icon 22 on the pre-processing screen 2.

[0031] The control unit 14 is configured with, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The CPU controls the operation of each unit of the information processing device 1 by using the RAM as a work memory and appropriately executing various programs stored in the ROM and various software stored in the storage unit 11.

[0032] In this embodiment, in order to efficiently generate learning data, the control unit 14 generates annotation data for images of symbols representing facilities based on CAD (Computer Aided Design) data. Then, the control unit 14 performs machine learning on the images of symbols representing facilities using a framework to generate learning data. Note that for symbols of facilities that could not be picked up in the single-tracking process, machine learning using the framework can be performed again.

[0033] In this embodiment, in response to a user operating the operation unit 13 to select a building plan 21 to be displayed from among the building plans 21 indicated by the building plan data stored in the storage unit 11, the control unit 14 displays on the display unit 12 a pre-processing screen 2 shown in Fig. 2 including the selected building plan 21. Then, in response to a user clicking a single-tracking instruction icon 22 on the pre-processing screen 2, the control unit 14 executes the single-tracking program 110 stored in the storage unit 11 to perform the single-tracking process.

[0034] 4 and 5 are diagrams for illustrating and explaining the single-tracking process.

[0035] In the single-line processing, the control unit 14 first detects both end points of a line segment (first line segment), the start and end points (start and end points) and midpoints of a circular arc, and the start, end points and inflection points of a free curve from the building plan 21. The control unit 14 also detects annotations such as "toilet" and "living room 11 tatami mats" written on the building plan 21, encloses them in rectangular areas, and stores them in RAM or the like as data to be used in generating the single-line drawing 31 that will be performed later.

[0036] Next, the control unit 14 removes overlapping line segments and curves (circular arcs, free-form curves, etc.) included in the building drawing 21. Specifically, the control unit 14 determines whether line segments are overlapping based on whether the endpoints, type, line width, layer, and pen type used to draw the line segments are the same. The control unit 14 also determines whether arcs are overlapping based on whether the start and end points and midpoints, type, line width, layer, and pen type used to draw the arcs are the same. Furthermore, the control unit 14 determines whether free-form curves are overlapping based on whether the start and end points and inflection points, type, line width, layer, and pen type used to draw the free-form curves are the same. The control unit 14 then retains any overlapping line segments and curves and removes the other line segments and curves.

[0037] Next, the control unit 14 classifies the line segments, from which overlapping ones have been removed, into horizontal line segments and vertical line segments.

[0038] Furthermore, the control unit 14 detects and excludes lines and curves indicating fixtures, equipment, etc. from the building plan 21. Specifically, the control unit 14 first detects a closed area surrounded by lines and curves from the building plan 21. Next, the control unit 14 determines whether the area of ​​the detected closed area is equal to or less than half the total area of ​​the building. If the area of ​​the detected closed area is equal to or less than half the total area of ​​the building, the control unit 14 then determines whether the width of the lines and curves constituting the closed area is greater than the preset width of the wall. If the width of the lines and curves constituting the closed area is greater than the preset width of the wall of the building, the control unit 14 determines that the closed area indicates fixtures, equipment, etc., and excludes it from the building plan 21.

[0039] Next, the control unit 14 executes a line segment clustering process. Specifically, the control unit 14 detects and removes line segments that are shorter than a predetermined length from the building drawing 21, and generates continuous line segments that are equal to or longer than the predetermined length.

[0040] Furthermore, as shown in Figure 4(a), the control unit 14 detects two line segments (a pair of line segments) that are in the same direction (line segments in the horizontal direction or in the vertical component direction) and whose distance between them is less than a predetermined threshold as a pair of line segments that indicate the wall of a building.

[0041] Next, the control unit 14 optimizes the detected paired line segments, taking into consideration the overlapping of paired line segments in the horizontal direction and paired line segments in the vertical direction.

[0042] Furthermore, as shown in FIG. 4(b), the control unit 14 generates a line segment (hereinafter referred to as a "block line segment") that passes through approximately the middle of the pair of line segments in the longitudinal direction, and generates a grid made up of the block line segments (second line segments).

[0043] Furthermore, the control unit 14 uses artificial intelligence (AI) to extract symbols indicating equipment from the image of the building plan 21. Specifically, first, the control unit 14 performs image segmentation processing to image and segment the building plan 21 (the building plan 21 before single-track processing) indicated by the building plan data stored in the memory unit 11. The size of the segmented image can be arbitrarily changed in a setting file as long as it is smaller than the image of the building plan 21; in this embodiment, it is set to 100 pixels vertically and 100 pixels horizontally. Furthermore, an offset value is set in consideration of the fact that the target equipment will overlap the position to be segmented; in this embodiment, the offset value is set to 50 pixels. The control unit 14 then extracts symbols indicating equipment using the learning data, the segmented image, etc.

[0044] FIG. 6 is an explanatory diagram illustrating an example of picking out symbols indicating facilities.

[0045] As shown in Figures 6(a) to (c), on the image of the building plan 21, a divided image of 100 pixels vertically and 100 pixels horizontally is moved by 50 pixels in the X-axis direction, and symbols contained in the divided image are picked out.

[0046] Specifically, symbols that are entirely contained within a divided image are picked out, but symbols that are only partially contained are not picked out. In the example shown in Figure 6(a), symbol A is picked out because its entirety is contained within divided image 61, but symbol B is not picked out because only a portion of it is contained within divided image 61. In the example shown in Figure 6(b), symbols A and B are both picked out because their entirety is contained within divided image 62. In the example shown in Figure 6(c), symbol B is not picked out because only a portion of it is contained within divided image 63.

[0047] Furthermore, symbols that are picked up in duplicate in two consecutive divided images are counted as one. For example, symbol A is picked up in duplicate in divided images 61 and 62, but is counted as one.

[0048] 1 moves the divided images as described above, and uses learning data, etc. to pick out symbols indicating equipment from the image of the building plan 21. Then, the control unit 14 stores the picked-out symbols in RAM, etc. as data to be used in the subsequent generation of the single-line plan 31.

[0049] Next, as shown in FIG. 5(a), the control unit 14 compares the grid with the paired line segments, and deletes, as unnecessary edges, portions of the block line segments that make up the grid that do not overlap with the paired line segments, leaving only portions that overlap with the paired line segments, thereby generating block line segments (hereinafter referred to as "wall lines") that indicate the walls of the building shown in FIG. 5(b). Specifically, the control unit 14 may delete, as unnecessary edges, portions of the block line segments that make up the grid that do not have parallel paired line segments or portions that overlap little with the paired line segments (for example, portions that do not overlap by 40% or more). In this way, the control unit 14 can convert the lines that indicate the walls of the building drawn on the building drawing 21 into single lines.

[0050] Furthermore, the control unit 14 generates a single-line drawing 31 in which the lines indicating the walls of the building drawn on the building drawing 21 are single-lined using symbols indicating annotations and equipment stored in RAM, etc., and the generated wall lines.

[0051] Then, the control unit 14 displays the post-processing screen 3 shown in FIG. 3 on the display unit 12, which includes the generated single-line drawing 31.

[0052] Next, the operation of the information processing device 1 having the above configuration will be described with reference to the drawings.

[0053] In response to a user operating the operation unit 13 to select a building plan 21 to be displayed from among the building plans 21 indicated by the building plan data stored in the memory unit 11, the control unit 14 displays a pre-processing screen 2 including the selected building plan 21 on the display unit 12. Then, in response to a user clicking on the single-line instruction icon 22 on the pre-processing screen 2, the information processing device 1 starts the single-line processing.

[0054] FIG. 7 is a flowchart showing an example of the single-tracking process.

[0055] In the single-line processing shown in Figure 7, the control unit 14 first detects both end points of a line segment, the start and end points and midpoints of an arc, and the start and end points and inflection points of a free curve from the building drawing 21, and also detects annotations, encloses them in a rectangular area, and stores them in RAM, etc. (step S71).

[0056] Next, the control unit 14 removes overlapping lines and curves from among the lines and curves included in the building drawing 21 (step S72).

[0057] Next, the control unit 14 classifies the line segments, from which overlapping ones have been removed, into horizontal line segments and vertical line segments (step S73).

[0058] Furthermore, the control unit 14 detects and removes lines and curves indicating fixtures, equipment, etc. from the building plan 21 (step S74).

[0059] Next, the control unit 14 executes a line segment clustering process to detect and remove line segments shorter than a preset length from the building drawing 21, and generate continuous line segments having a length equal to or greater than the preset length (step S75).

[0060] Furthermore, the control unit 14 detects two line segments that are in the same direction and whose distance between them is less than a predetermined threshold value as a pair of line segments that indicate the walls of a building (step S76).

[0061] Next, the control unit 14 optimizes the paired line segments detected in step S76, taking into consideration the overlapping of paired line segments in the horizontal direction and paired line segments in the vertical direction (step S77).

[0062] Furthermore, the control unit 14 generates a grid made up of block line segments that pass through approximately the middle of the paired line segments in the longitudinal direction (step S78).

[0063] Furthermore, the control unit 14 uses artificial intelligence to pick up symbols indicating the equipment from the image of the building plan 21 and store them in RAM or the like (step S79).

[0064] Next, the control unit 14 compares the grid with the paired line segments, and deletes the portions of the block line segments that make up the grid that do not overlap with the paired line segments as unnecessary edges, leaving only the portions that overlap with the paired line segments, thereby generating block line segments (wall lines) that indicate the walls of the building (step S80).

[0065] Furthermore, the control unit 14 generates a single-line drawing 31 by single-lining the lines indicating the walls of the building drawn on the building drawing 21 using symbols indicating annotations and equipment stored in RAM, etc., and the wall lines generated in step S80 (step S81).

[0066] Then, the control unit 14 displays the post-processing screen 3 shown in FIG. 3, including the single-track drawing 31 generated in step S81, on the display unit 12 (step S82), and then ends the single-tracking process.

[0067] As described above, the control unit (pair detection means) 14 of the information processing device (drawing processing device) 1 according to this embodiment detects pairs (paired line segments) of line segments (first line segments) indicating building walls from among the line segments (first line segments) drawn on the building drawing 21 (step S76). Then, the control unit (single-line conversion means) 14 generates a block line segment (second line segment) that passes through approximately the middle of the pair of line segments (paired line segments) detected in step S76, thereby single-lining the line segments indicating the building walls (steps S78 and S80).

[0068] Specifically, the control unit (pair detection means) 14 detects two line segments (first line segments) drawn on the building drawing 21 that are in the same direction and whose distance between them is less than a predetermined threshold as a pair of line segments (first line segments) indicating the walls of the building (step S76).

[0069] The control unit (single-line means) 14 generates a grid consisting of block line segments (second line segments) (step S78), and deletes the portions of the block line segments (second line segments) that make up the grid that do not overlap with paired line segments (pairs of first line segments) that represent the walls of the building, thereby generating wall lines that are block line segments (second line segments) that represent the walls of the building, thereby single-lining the lines that represent the walls of the building (step S80).

[0070] In this way, according to the information processing device 1, single-tracking can be performed automatically from the building drawing 21, so that the work of tracing from step 1 can be significantly shortened.

[0071] The control unit (symbol picking means) 14 also picks out symbols indicating equipment from the image of the building drawing 21 (step S79). Then, the control unit (symbol picking means) 14 generates a single-line drawing 31 in which the lines indicating the walls of the building are single-lined, using the wall lines that are block lines (second lines) indicating the walls of the building generated in step S80 and the symbols indicating the equipment picked out in step S79 (step S81).

[0072] Specifically, the control unit (symbol extraction means) 14 extracts symbols indicating equipment from the image of the building plan 21 by moving divided images that are smaller than the image of the building plan 21 on the image of the building plan 21, and extracting only symbols that are entirely contained within the divided images, without extracting symbols that are only partially contained within the divided images, and if the same symbol is extracted twice in two consecutive divided images, it is counted as one symbol.

[0073] This allows the information processing device 1 to accurately detect the equipment on the building drawing 21.

[0074] In this way, the information processing device 1 can easily simplify the building drawing 21.

[0075] The present invention is not limited to the above-described embodiment, and various modifications and applications are possible. Modifications of the above-described embodiment that can be applied to the present invention will be described below.

[0076] In the above embodiment, the output of the single line drawing 31 is described as being displayed on the display unit 12 of the information processing device 1. However, the present invention is not limited to this, and the output may be something other than a display, such as output to a CSV (Comma-Separated Values) file.

[0077] In the above embodiment, the information processing device 1 is described as performing the single-tracking process. However, the present invention is not limited to this. A server device (not shown) connected to the information processing device 1 via a network may perform the single-tracking process. In this case, the information processing device 1 operates the operation unit 13 to select a building plan 21 to be displayed from among the building plans 21 represented by the building plan data stored in the storage unit 11, and then, in response to clicking the single-tracking instruction icon 22 on the pre-processing screen 2, transmits a single-tracking request to the server device via the network, the single-tracking request including data (building plan data) representing the building plan 31 selected by the user and requesting single-tracking of the line segments representing the walls of the building depicted on the building plan 31. In response to receiving the single-tracking request transmitted from the information processing device 1 via the network N at the communication unit 51, the server device performs the same processes as steps S71 to S81 shown in FIG. 7 to single-track the line segments representing the walls of the building depicted on the building plan 21 represented by the building plan data included in the single-tracking request, thereby generating the single-tracked building plan 31. The server device then transmits single-track drawing data indicating the generated single-track drawing 31 to the information processing device 1 via the network. In response to receiving the single-track drawing data transmitted from the server device via the network, the information processing device 1 displays the processed screen 3 shown in FIG. 3 on the display unit 12, including the single-track drawing 31 based on the received single-track drawing data. In this case, the server device functions as the drawing processing device according to the present invention. Alternatively, the information processing device 1 and the server device may each perform the role of executing the single-tracking process. In this case, a computer system including the information processing device 1 and the server device functions as the drawing processing device according to the present invention. Note that the output is not limited to that on the information processing device 1 side, but may also be that on the server device side.

[0078] In the above embodiment, the program executed by the CPU of the control unit 14 is stored in advance in a ROM or the like. However, the present invention is not limited to this, and the program for executing the above-described processing may be applied to an existing general-purpose computer to function as the information processing device 1 according to the above embodiment.

[0079] Such programs may be provided in any manner, for example, by storing them on a computer-readable recording medium (such as a flexible disk, a CD (Compact Disc)-ROM, or a DVD (Digital Versatile Disc)-ROM) and distributing them, or by storing the programs in storage on a network such as the Internet and providing them by downloading them.

[0080] Furthermore, when the above processing is performed by sharing the work between the OS and the application program, or by cooperation between the OS and the application program, only the application program may be stored on a recording medium or storage. It is also possible to superimpose the program on a carrier wave and distribute it over a network. For example, the program may be posted on a bulletin board system (BBS) on a network and distributed over the network. The program may then be started and executed under the control of the OS in the same way as other application programs, thereby enabling the above processing to be performed. [Explanation of symbols]

[0081] 1. Information processing equipment 2 Pre-processing screen 3. Post-processing screen 11 Storage section 12 Display section 13 Control section 14 Control Unit 21 Building drawings 22 Single track instruction icon 31 Single-track drawing 61~63 Split images 110 Single Track Program

Claims

1. a pair detection means for detecting pairs of first line segments representing walls of a building from among first line segments drawn on a building plan; a single-tracking means for generating a second line segment that passes through approximately the middle of the pair of first line segments detected by the pair detection means, thereby single-tracking the line segments that represent the walls of the building; A drawing processing device comprising:

2. The pair detection means two of the first line segments drawn on the building plan that are in the same direction and whose distance between them is less than a predetermined threshold are detected as a pair of first line segments that indicate walls of the building; 2. The drawing processing apparatus according to claim 1.

3. The single track means is generating a grid consisting of the second line segments; a part of the second line segments constituting the grid that does not overlap with the pair of first line segments that represent the wall of the building is deleted to generate the second line segments that represent the wall of the building, thereby converting the line segments that represent the wall of the building into a single line; 2. The drawing processing apparatus according to claim 1.

4. symbol extraction means for extracting symbols indicating facilities from the image of the building plan; a single-track drawing generating means for generating a single-track drawing by single-tracking the line segments representing the walls of the building, using the second line segments representing the walls of the building generated by the single-tracking means and the symbols representing the facilities picked up by the symbol picking means; The drawing processing apparatus according to claim 3 , further comprising:

5. The symbol picking means moves divided images smaller than the image of the building plan on the image of the building plan, and picks out only symbols that are entirely contained within the divided images without picking out symbols that are only partially contained within the divided images, thereby picking out symbols indicating the equipment from the image of the building plan, and when the same symbol is picked up twice in two consecutive divided images, it counts them as one symbol.

5. The drawing processing apparatus according to claim 4.

6. a pair detection step of detecting pairs of first line segments representing walls of a building from among first line segments drawn on the building plan; a single-tracking step of generating a second line segment that passes through approximately the middle of the pair of first line segments detected in the pair detection step, thereby single-tracking the line segment that indicates the wall of the building; A drawing processing method comprising:

7. On the computer, a pair detection step of detecting pairs of first line segments representing walls of a building from among first line segments drawn on a building plan; a single-tracking procedure for single-tracking the line segments representing the walls of the building by generating a second line segment that passes through approximately the middle of the pair of first line segments detected by the pair detection procedure; A program to execute.

Images