A 3D translation method and system for orthophotos of traditional villages

Abstract

The present invention is applicable to the technical field of urban and rural planning, and provides a three-dimensional translation method and system for orthophoto images of traditional villages. The method includes: obtaining spatial point cloud data of a target area, and processing the spatial point cloud data to generate an orthophoto image and an overall three-dimensional display model; extracting the peripheral boundary of the target area according to the orthophoto image and the spatial point cloud data, and extracting the group boundary of the target area through the orthophoto image; identifying the public space of the target area in the orthophoto image, where the public space at least includes a road system and an open space; constructing a road layer from the road system and converting the public space into a public space layer; identifying the building groups in the orthophoto image, determining the group orientation, dividing the group plots, and determining the minimum unit of homestead. The present invention constructs a technical path for quickly generating a three-dimensional model of a traditional village in a region based on orthophoto images taken by drones from three aspects: village boundary extraction, public space identification, and building texture extraction.

Description

Technical Field

[0001] The invention belongs to the technical field of urban and rural planning, and provides a three-dimensional translation method and system for orthophotos of traditional villages. Background Art

[0002] The Loess Gully Area has a complex topography, with drought in three seasons and concentrated and heavy rain in summer. According to statistics on the list of traditional Chinese villages, about 50% of the traditional villages in the Loess Plateau are concentrated here. Research on traditional villages in this area has always been a hot topic in the fields of architecture and planning. Most villages in this area do not have detailed surveying and mapping data. In order to better protect and inherit the wisdom of human settlement contained in traditional villages in this area, researchers are required to conduct a lot of research and analysis.

[0003] Due to the complex topography of the Loess Gully Area and the scattered distribution of traditional villages, traditional research methods are usually time-consuming and labor-intensive, and it is difficult to quickly generate a basic visual working model. Although remote sensing and drone oblique photography technology can be used to collect and visualize relevant data, the generated models are mostly based on landscape display. Although they can be converted into model files in 3dm, obj and other formats for researchers to conduct in-depth analysis and creation, the converted files are large in size and are complete surfaces, which are not easy to process in layers. The difficulty and workload of later editing and correction are huge, which limits the work efficiency of researchers and requires improvement. Summary of the invention

[0004] The purpose of the present invention is to provide a three-dimensional translation method and system for orthophotos of traditional villages to solve the problems raised by the above-mentioned background technology; the present invention is aimed at the demand for digital auxiliary technology in traditional village research, systematically sorts out the current common and easy-to-use digital software tools, constructs easy-to-operate and highly versatile digital auxiliary research and design technical paths and application processes, and effectively connects with relevant research on regional traditional villages, thereby improving work efficiency.

[0005] The present invention is implemented as follows: a three-dimensional translation method of a traditional village orthophoto, the method comprising:

[0006] Step S100: acquiring spatial point cloud data of the target area, and processing the spatial point cloud data to generate an orthophoto and an overall three-dimensional display model;

[0007] Step S200: extracting the outer boundary of the target area according to the orthophoto and the spatial point cloud data, and extracting the group boundary of the target area through the orthophoto;

[0008] Step S300: Identify the public spaces in the target area in the orthophoto, where the public spaces at least include a road system and open spaces; construct a road layer from the road system and convert the public spaces into a public space layer;

[0009] Step S400: Identify the building clusters in the orthophoto, determine the cluster orientation, divide the cluster plots, determine the minimum unit of homestead, determine the texture and height parameters of the building clusters based on specified rules, and generate a building mass model layer;

[0010] Step S500: Reconstruct the overall 3D display model, road layer, public space layer, and building mass model layer to obtain an editable 3D model of the target area.

[0011] Further, in Step S100, spatial point cloud data of the target area is obtained by using an unmanned aerial vehicle with the unmanned aerial vehicle oblique photography technology.

[0012] Further, the specific steps of Step S200 include:

[0013] Using the orthophoto as the base map, combine the spatial point cloud data to extract the outer boundary of the target area;

[0014] Preprocess the orthophoto, and use the GH plugin (the GH plugin is a visual programming module embedded in the Rhino software, full name Grasshopper) to extract the cluster boundary;

[0015] Check and correct the cluster boundary according to the measured data.

[0016] Further, after identifying the public spaces in the target area in Step S300, the public spaces are also checked and corrected by the measured data.

[0017] Further, the specific steps of Step S400 also include:

[0018] Construct a machine learning model to predict the residential plane type based on the homestead form;

[0019] Construct a texture adaptive model library;

[0020] Substitute the residential plane type into the texture adaptive model library to obtain a hierarchical editable 3D model of the village.

[0021] Further, the method also includes:

[0022] Step S600: Conduct building physical environment simulation on the 3D model of the target area; or conduct village rainwater runoff simulation on the 3D model of the target area; or conduct village renewal design recommendations on the 3D model of the target area.

[0023] The present invention also provides a three-dimensional translation system for the orthophoto of traditional villages, and the system includes:

[0024] A data acquisition module, configured to acquire the spatial point cloud data of the target area, and process the spatial point cloud data to generate an orthophoto and an overall three-dimensional display model;

[0025] A village boundary extraction module, configured to extract the peripheral boundary of the target area according to the orthophoto and the spatial point cloud data, and extract the group boundary of the target area through the orthophoto;

[0026] A public space recognition module, configured to recognize the public space of the target area in the orthophoto, and the public space at least includes a road system and an open space; construct a road layer from the road system, and convert the public space into a public space layer;

[0027] A building texture generation module, configured to recognize the building groups in the orthophoto, determine the group orientation, divide the group plots, determine the minimum unit of the homestead, determine the texture and height parameters of the building groups based on specified rules, and generate a building block model layer;

[0028] A post-processing module, configured to reconstruct the overall three-dimensional display model, the road layer, the public space layer, and the building block model layer to obtain an editable three-dimensional model of the target area.

[0029] Further, the system further includes: a result verification module, configured to compare the similarity between the three-dimensional model of the target area and the orthophoto.

[0030] Further, the system further includes: an extended application module, configured to perform an extended simulation of the application scenario on the three-dimensional model of the target area.

[0031] A three-dimensional translation method for the orthophoto of traditional villages provided by the present invention comprehensively uses multiple software tool platforms (such as LIDAR360, ENVI, Rhino+Grasshopper software), and constructs a technical path for quickly generating a three-dimensional model of the traditional village in the target area based on the orthophoto from three aspects: village boundary extraction, public space extraction, and building texture extraction. The generated model can effectively dock with spatial analysis software related to architectural design and planning design to carry out subsequent research work or in-depth creative work; the present invention solves the problem of lacking basic surveying and mapping data for carrying out research work on traditional villages in the target area; and obtains a work model that can be generated in layers, such as a site layer, a building layer, and a road layer, and can perform layer-by-layer editing and unfolding analysis work on the work model according to research and design needs, improving work efficiency. Description of the Drawings

[0032] Figure 1It is a principle flowchart of a three-dimensional translation method for the orthophoto of traditional villages provided by an embodiment of the present invention;

[0033] Figure 2 It is a flowchart for extracting the village boundary in an embodiment;

[0034] Figure 3 It is a legend for extracting the village boundary in an embodiment;

[0035] Figure 4 It is a flowchart for identifying public spaces in an embodiment;

[0036] Figure 5 It is a legend for identifying public spaces in an embodiment;

[0037] Figure 6 It is a flowchart for generating building textures in an embodiment;

[0038] Figure 7 It is a legend for generating building textures in an embodiment;

[0039] Figure 8 It is for comparing the similarity of generation results in an embodiment Figure 1 ;

[0040] Figure 9 It is for comparing the similarity of generation results in an embodiment Figure 2 ;

[0041] Figure 10 It is a complete legend for a three-dimensional translation method for the orthophoto of traditional villages in an embodiment;

[0042] Figure 11 It is a legend for the extended application of generation results in an embodiment. Specific embodiments

[0043] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] In practice, the landform in the loess gully area is complex, with drought in three seasons, concentrated summer rain and many heavy rains. According to the statistics of the list of traditional Chinese villages, about 50% of the traditional villages in the Loess Plateau are concentrated here. The research on traditional villages in this area has always been a hot topic in the fields of architecture and planning. Since most villages do not have detailed surveying and mapping data, in order to better protect and inherit the human settlement wisdom contained in the traditional villages in this area, it is required that researchers carry out a large amount of research and analysis work; traditional research methods are usually time-consuming and laborious, and it is difficult to quickly generate a visual basic work model; based on this, this embodiment provides a three-dimensional translation method for orthophotos of traditional villages. The method will be introduced in more detail below.

[0045] As Figures 1-9 shown, in one embodiment, a three-dimensional translation method for orthophotos of traditional villages, the method includes the following steps:

[0046] Step S100: Obtain the spatial point cloud data of the target area, and process the spatial point cloud data to generate an orthophoto and an overall three-dimensional display model;

[0047] In this step, the spatial point cloud data of the target area can be obtained by using an unmanned aerial vehicle (UAV) with the UAV oblique photography technology; specifically, a DJI UAV can be used to obtain the spatial point cloud data of the village, and the LiDAR36 software can be used to classify and extract elements such as buildings, roads, and sites, and the DJI Smart Mapping software can be used to generate an orthophoto; and image stitching software such as Photoshop and Rhino can be used to optimize the orthographic projection image (or orthophoto), and to create an overall three-dimensional display model.

[0048] Step S200: Extract the outer boundary of the target area according to the orthophoto and the spatial point cloud data, and extract the group boundary of the target area through the orthophoto;

[0049] In this step, software such as Photoshop and Rhino can be used to extract the outer boundary, and software or plugins such as ENVI, Photoshop, and Grasshopper can be used to extract the group boundary. GH-LandsDesign and GH-Slime in the figure are plugins in Grasshopper;

[0050] In an example of this embodiment, as Figure 2 shown, the step S200 specifically includes:

[0051] Taking the orthophoto as the base map, combined with the spatial point cloud data to extract the outer boundary of the target area; the basic range for generating the village basic model can be determined according to the outer boundary to extract the overall boundary of the village, and the range for generating the village basic model can be determined;

[0052] Preprocess the orthophoto image and use the GH plugin (i.e., the Grasshopper plugin, an extension component of the powerful parametric design tool Grasshopper in Rhino software) to extract the boundaries of clusters; among them, the preprocessing is mainly to perform file format conversion to facilitate the execution of the GH plugin. For example, combine the road information and site elevation information in the village to extract the boundaries of clusters within the village and determine the boundary range for generating building blocks within the village clusters.

[0053] Check and correct the boundaries of clusters based on the measured data; both checking and correction can be carried out by the staff.

[0054] Among them, the measured data can be obtained through on-site exploration by the staff or by other means, such as using remote sensing satellites, drones, etc.

[0055] Finally, obtain the outer boundary and the boundaries of clusters, that is, the extraction of the double boundaries is completed. See Figure 3 。

[0056] Step S300: Identify the public spaces in the target area of the orthophoto image. The public spaces at least include the road system and open spaces; construct a road layer from the road system and convert the public spaces into a public space layer.

[0057] In an example of this step, as Figure 4 shown, step S300 may include:

[0058] Perform secondary processing on the orthophoto image to classify the point cloud information of the village traffic space and open spaces; to facilitate the extraction of the road system and the division of open spaces.

[0059] Extract the road system, extract the main road data information, adjust the parameters in combination with the site characteristics, and construct a road network skeleton model layer or a road layer.

[0060] Finally, extract the open spaces and convert them into a separate model layer, that is, the public space layer; the result is shown in Figure 5 。

[0061] In some scenarios, GH image data conversion can be performed to facilitate the subsequent reconstruction or editing of the layers.

[0062] Step S400: Identify the building clusters in the orthophoto image, determine the orientation of the clusters, divide the cluster plots, determine the minimum unit of homestead, determine the texture and height parameters of the building clusters based on the specified rules, and generate a building block model layer.

[0063] Among them, divide the cluster plots: identify the courtyard and building contour lines in the orthophoto image and subdivide the homesteads in the village clusters.

[0064] Based on specified rules, it can be sorted out and summarized from the plane form of folk houses, which are input or set by the staff; for example: setting the orientation parameters of the building and the road network, dividing the homestead and the building foundation plane, and assigning height parameters to the building blocks.

[0065] Step S500: Reconstruct the overall three-dimensional display model, road layer, public space layer, and building block model layer to obtain an editable three-dimensional model of the target area.

[0066] After obtaining the editable three-dimensional model of the target area as described above, on the basis of the generated model, it can be further docked with the Revit platform to refine the building facade form. Combining with the Rhino Inside Revt plug-in, classify and pick up and import it into the overall working model. The finally generated working model can be seamlessly connected to other relevant analysis software or plug-ins to carry out relevant research analysis and design creation work.

[0067] In an example of this embodiment, as Figure 4 shown, in step S300, after identifying the public space in the orthophoto of the target area, the public space is also checked and corrected through measured data.

[0068] Among them, the measured data can be completed by the staff, and the checking and correction can also be completed by the staff.

[0069] In an example of this embodiment, when obtaining the editable three-dimensional model of the target area, the three-dimensional terrain can be adjusted through GH-Bison (a plug-in of Grasshopper).

[0070] In an example of this embodiment, as Figure 6 shown, step S400 further includes:

[0071] Construct a machine learning model to predict the residential plane type based on the homestead form;

[0072] Among them, for the machine learning model, LunchboxML is selected. It is a component in the Lunchbox plug-in that focuses on machine learning (ML). Lunchbox itself is a plug-in of Grasshopper;

[0073] It can be understood that the machine learning model can be trained first, and the training sample set is made based on the data sorted out and summarized from the plane form of folk houses;

[0074] Construct a texture adaptive model library (or called adaptive model library, or called adaptive building model library);

[0075] Substitute the residential plane type into the texture adaptive model library to obtain a three-dimensional model of the village that can be edited in layers. For specific results, please refer to Figure 7 .

[0076] In one example of this embodiment, the texture adaptive model library can be constructed based on the texture characteristics of folk houses;

[0077] Specific software used includes: Grasshopper of Rhino, Revit, GHPython, etc.

[0078] In one example of this embodiment, as Figure 11 shown, the method further includes:

[0079] Step S600: Conduct building physical environment simulation on the three-dimensional model of the target area; or, conduct village rainwater runoff simulation on the three-dimensional model of the target area; or, conduct village renewal design recommendation on the three-dimensional model of the target area.

[0080] The simulation results of this step can effectively interface with spatial analysis software related to architectural design and planning design to carry out subsequent research work or in-depth creative work.

[0081] Among them, the three-dimensional model of the target area is a lightweight model, and the model format of the lightweight model is convenient for interfacing with other analysis software;

[0082] Conduct village renewal design recommendation: Specifically, it is convenient to conduct update design deduction or spatial feature analysis based on the generated result model.

[0083] In another embodiment, as Figure 1 、 Figure 10 shown, a three-dimensional translation system for the orthophoto of traditional villages, the system includes:

[0084] Data acquisition module, used to acquire the spatial point cloud data of the target area, and process the spatial point cloud data to generate an orthophoto and an overall three-dimensional display model;

[0085] Village boundary extraction module, used to extract the outer boundary of the target area according to the orthophoto and the spatial point cloud data, and extract the group boundary of the target area through the orthophoto;

[0086] Public space recognition module, used to recognize the public space in the orthophoto of the target area, and the public space at least includes a road system and an open space; construct a road layer from the road system, and convert the public space into a public space layer;

[0087] The building texture generation module is used to identify building clusters in the orthophoto, determine the orientation of the clusters, divide the cluster plots, determine the minimum unit of homestead, determine the texture and height parameters of the building clusters based on specified rules, and generate a building mass model layer;

[0088] The post-processing module is used to reconstruct the overall three-dimensional display model, road layer, public space layer, and building mass model layer to obtain an editable three-dimensional model of the target area.

[0089] In this embodiment, the system sorts out current general and easy-to-use digital software tools, constructs a technical path and application process for easy-to-operate and highly general digital auxiliary research and design, and the generated results can be effectively connected to other professional analysis software to carry out research work, improving the research work efficiency; and it can be effectively connected to relevant research on traditional villages in the region, improving work efficiency, and has important value and significance.

[0090] In an example of this embodiment, as Figure 8 、 Figure 9 shown, the system further includes: a result verification module for comparing the similarity between the three-dimensional model of the target area and the orthophoto.

[0091] In this example, by comparing the generation results of Lidi Po Village with the orthophoto of Lidi Po Village, it is found that the similarity is extremely high; by comparing the discrete cosine transform frequency maps and digital feature maps of the two, the similarity is as high as 93.06%.

[0092] Among them, the result verification module can be a WeChat mini-program for image similarity detection or computer program instructions.

[0093] In an example of this embodiment, as Figure 11 shown, the system further includes: an extended application module for performing extended simulation of application scenarios on the three-dimensional model of the target area.

[0094] This embodiment provides a three-dimensional translation method for traditional village orthophotos, and based on this method, a three-dimensional translation system for traditional village orthophotos is provided. This method constructs a technical path for quickly generating a three-dimensional model of a traditional village in the target area from three aspects: village boundary extraction, public space extraction, and building texture extraction. The generated model can be effectively connected to spatial analysis software related to architectural design and planning design to carry out subsequent research work or in-depth creative work; the present invention solves the problem of lacking basic surveying and mapping data for carrying out research work on traditional villages in the target area; a work model that can be generated in layers is obtained, such as a site layer, a building layer, and a road layer, and layer editing and expansion analysis work can be carried out on the work model according to research and design needs, improving work efficiency.

[0095] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

[0096] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A three-dimensional translation method of traditional village orthophotos, characterized in that: The method comprises: Step S100: acquiring spatial point cloud data of a target area, and processing the spatial point cloud data to generate an orthophoto and an overall three-dimensional display model; Step S200: extracting the outer boundary of the target area according to the orthophoto and the spatial point cloud data, and extracting the group boundary of the target area through the orthophoto; Step S300: identifying the public space of the target area in the orthophoto, the public space at least including a road system and an open space; constructing a road layer from the road system, and converting the public space into a public space layer; Step S400: Identify the building cluster in the orthophoto, determine the cluster orientation, divide the cluster plot, determine the minimum unit homestead, determine the texture and height parameters of the building cluster based on the specified rules, and generate a building block model layer; Step S500: Reconstruct the overall three-dimensional display model, road layer, public space layer, and building block model layer to obtain an editable three-dimensional model of the target area.

2. The method according to claim 1, characterized in that In step S100, the spatial point cloud data of the target area is acquired by using a drone using the drone oblique photography technology.

3. The method according to claim 1, characterized in that The step S200 specifically includes: Orthophotos are used as base maps, and spatial point cloud data are combined to extract the outer boundaries of the target area; Preprocess the orthophoto and use the GH plug-in to extract the cluster boundaries; The cluster boundaries are checked according to the measured data and the boundaries are corrected.

4. The method according to claim 1, characterized in that: In step S300, after identifying the public space of the target area in the orthophoto, the public space is checked and corrected using the measured data.

5. The method according to claim 1, characterized in that The step S400 further includes: Build a machine learning model to predict residential floor plan type based on homestead morphology; Build a texture adaptive model library; Substitute the residential plane types into the texture adaptive model library to obtain a hierarchically editable three-dimensional model of the village.

6. The method according to claim 1, characterized in that The method further comprises: Step S600: Performing a building physical environment simulation on the three-dimensional model of the target area; or, performing a village rainwater runoff simulation on the three-dimensional model of the target area; or, performing a village renewal design recommendation on the three-dimensional model of the target area.

7. A three-dimensional translation system for traditional village orthophotos, characterized in that: The system comprises: A data acquisition module is used to acquire spatial point cloud data of a target area and process the spatial point cloud data to generate an orthophoto and an overall three-dimensional display model; The village boundary extraction module is used to extract the outer boundary of the target area based on the orthophoto and spatial point cloud data, and to extract the group boundary of the target area through the orthophoto; The public space recognition module is used to recognize the public space of the target area in the orthophoto, and the public space includes at least a road system and an open space; a road layer is constructed from the road system, and the public space is converted into a public space layer; The building texture generation module is used to identify building clusters in orthophotos, determine the orientation of the clusters, divide the cluster plots, determine the minimum unit homestead, determine the texture and height parameters of the building clusters based on specified rules, and generate a building block model layer; The post-processing module is used to reconstruct the overall three-dimensional display model, road layer, public space layer, and building block model layer to obtain an editable three-dimensional model of the target area.

8. The system according to claim 7, characterized in that The system also includes: a result verification module, which is used for comparing the similarity between the three-dimensional model of the target area and the orthophoto.

9. The system according to claim 7, characterized in that The system also includes: an extended application module, which is used to perform extended simulation of application scenarios on the three-dimensional model of the target area.

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