Monomer building contour batch extraction method based on live-action three-dimensional model

Abstract

The invention relates to a monomer building contour batch extraction method based on a live-action three-dimensional model, and the method can achieve the quick and batch extraction of building contours, and controls the contour extraction precision and the batch endowing height. Comprising the following steps: S1, based on a live-action three-dimensional model, cutting osgb data by adopting a facade cutting technology, and cutting off redundant models on the ground so as to obtain a building three-dimensional model; s2, performing orthographic grid image production on the cut osgb model data by using an orthographic output basic tool to obtain grid tif data; s3, vectorizing the background of the grid tif data by using a grid vectorization algorithm to obtain vector shapefile data; s4, performing reverse vector cutting on the shapefile to obtain high-precision vector building contour data; s5, using a geometric calculation tool to calculate and generate a contour center point; and S6, extracting three-dimensional building altitudes corresponding to the x-y longitude and latitude by using coordinate mapping of the central point in the three-dimensional model, and obtaining vector point data with the altitudes.

Description

Technical Field

[0001] The present invention relates to the technical field of building outline extraction, and in particular to a method for batch extraction of monomerized building outlines based on real-scene three-dimensional models. Background Art

[0002] The three-dimensional real-scene model is the result of data captured by an airplane and automatically modeled by software. It is a 3D display of real objects. This loading method is often in pieces and blocks. If we want to separate the buildings, we need to individualize the different buildings, that is, we can select and highlight each building, add attributes, query and count them, etc. These data filled with attributes can meet the needs of refined management of smart cities.

[0003] To meet this demand, many technical solutions have been proposed in the prior art. The mainstream ones are cutting and vectorization. Vectorization is to draw the vector building outline of the real 3D building. After inputting the attribute information such as the height of the corresponding floor, the vector data is stretched and superimposed on the real 3D model to achieve the effect of dividing the buildings. This process requires manual data preprocessing, building outline drawing, height calculation and other operations, which often require multiple people to work together, consuming a lot of manpower and time costs. Therefore, how to realize a tool for rapid singulation is a technical problem to be solved. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a method for batch extraction of individual building contours based on real-life three-dimensional models, which can realize rapid and batch extraction of building contours, control the contour extraction accuracy and batch height assignment, and one person can operate multiple areas simultaneously.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for batch extraction of monomerized building outlines based on real-scene three-dimensional models, including the following:

[0006] S1. Based on the real-life 3D model, the facade cutting technology is used to cut the osgb data and remove the redundant ground model to obtain the 3D model of the building;

[0007] S2. Use the basic ortho output tool to produce ortho grid images for the cropped osgb model data to obtain grid tif data;

[0008] S3, using a raster-to-vector algorithm to vectorize the background of the raster tif data to obtain vector shapefile data;

[0009] S4, reverse vector clipping the shapefile to obtain high-precision vector building outline data;

[0010] S5. Use geometric calculation tools to calculate and generate the center point of the contour;

[0011] S6, using the coordinate mapping of the center point in the three-dimensional model, extracting the three-dimensional building altitude corresponding to the xy longitude and latitude, and obtaining vector point data with the altitude;

[0012] S7. Perform spatial tracking on the outline data and the center point data to obtain building outline data with height.

[0013] Preferably, the S1 specifically includes: S101. The ground and building altitudes of real-life three-dimensional data in different areas are different. The real-life three-dimensional osgb data are divided into blocks to obtain multiple model data sets with relatively uniform ground altitudes; S102. The facade cropping tool is used to perform facade cropping on the above-mentioned blocked osgb model data. After adjusting the cropping height, the cropping operation is performed to obtain a block model. According to the osgb data production rules, the entire osgb data and the scattered osgb data sets share a .xml file, and the file names will not be repeated, so the cropped block models can be directly merged into a folder to obtain cropped and integrated osgb data of the block building three-dimensional model.

[0014] Preferably, S2 specifically includes: S201, the orthophoto production standard can refer to the model resolution. If the model resolution is 3 cm, the orthophoto resolution can be up to 3 cm, and the contour extraction accuracy is ±3 cm; S202, the grid background value of the orthophoto tif data can be set to 0 or 255, and finally an orthophoto tif image with a self-set resolution and a black or white background is obtained.

[0015] Preferably, the S3 specifically includes: S301, using a raster vectorization algorithm to vectorize pixels with raster values ​​of 0 or 255 from the orthophoto to obtain shapefiles data of the peripheral area of ​​the building image.

[0016] Preferably, the S4 specifically includes: S401, using a vector clipping tool to reversely clip the shapefile obtained in S3 to obtain contour vector data of the building image area; S402, constructing a buffer for the contour vector data, optimizing the contour wrapping effect, and obtaining vector data that can completely surround the building model.

[0017] Preferably, the S6 specifically includes: S601, using a space mapping algorithm to record the altitude of each building center point in the three-dimensional model to obtain the vector point coordinates of the altitude.

[0018] Preferably, the S7 specifically includes: S701, using a spatial tracking algorithm to process the building outline and center point, so that the height data attached to the center point of each outline can also be matched to the outline, to obtain refined vector data that can wrap the building.

[0019] The beneficial effects achieved by the present invention are as follows: the method for batch extracting the outline of individual buildings based on real-scene three-dimensional models of the present invention mechanically batch extracts the outline of buildings based on real-scene three-dimensional models, firstly, the facade is cropped by a tool to remove redundant ground models, and the taller buildings are separated therefrom; then a two-dimensional orthophoto is produced for the cropped real-scene building three-dimensional model; then, a raster vectorization tool is used to vectorize the background value of the two-dimensional orthophoto (raster image), because of the difference between the building raster value and the black or white background raster value, the image background raster is vectorized, while the building raster is not vectorized, so that a gap in the building position is formed in the background vector data, and at this time, the building outline can be cropped out by performing reverse cropping; then, a geometric algorithm is used to calculate the center point of the outline to extract the three-dimensional building height, and the height value is associated with the building outline, so that the building outline data with the building height is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of the present invention;

[0021] Figure 2 A schematic diagram of a complete regional model for demonstrating the present invention;

[0022] Figure 3 A schematic diagram of a retained building model after the facade of the present invention is cut;

[0023] Figure 4 A schematic diagram of an orthophoto produced by the present invention;

[0024] Figure 5 It is a schematic diagram of the orthophoto after rasterization and vectorization of the present invention;

[0025] Figure 6 The schematic diagram of the effect of cutting out the building vectorized data and orthophoto superposition for the present invention;

[0026] Figure 7 A schematic diagram of the effect of stretching the building outline and superimposing the three-dimensional model after the building is given height according to the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0028] The present invention provides a method for batch extraction of monomeric building outlines based on real-scene three-dimensional models, such as Figure 1 As shown, the following steps are included:

[0029] S1, based on a real-life 3D model of a certain area, such as Figure 2 As shown in the figure, the facade clipping technology is used to clip the osgb data and remove the redundant ground model to obtain the three-dimensional building model, as shown in the figure. Figure 3 As shown, specifically including;

[0030] S101, the ground and building altitudes of real-scene 3D data in different areas are different, and the real-scene 3D osgb data is divided into blocks to obtain multiple model data sets with relatively uniform ground altitudes;

[0031] S102. Use the facade cropping tool to perform facade cropping on the above-mentioned block osgb model data, adjust the cropping height, and then perform the cropping operation to obtain the building model. According to the osgb data production rules, the complete osgb data and the scattered osgb data sets share a .xml file, and the file names will not be repeated, so the cropped block models can be directly merged into a folder to obtain the cropped and integrated osgb data of the block building three-dimensional model.

[0032] S2. Use the basic ortho output tool to produce ortho grid images for the cropped osgb model data to obtain grid tif data, such as Figure 4 As shown, the details are as follows;

[0033] S201. The production standard of orthophoto can refer to the model resolution. If the model resolution is 3cm, then the resolution of orthophoto can reach up to 3cm, and the contour extraction accuracy is ±3cm. Figure 4 It takes about 60 seconds to identify the outline of the building, and the resolution is set to 10 cm. Increasing the resolution will increase the extraction time, and vice versa, it will save time, which is also related to the accuracy required for identification;

[0034] S202. The grid background value of the ortho tif data can be set to 0 or 255, and finally an ortho tif image with a self-set resolution and a black (white) background is obtained.

[0035] S3, using a raster vectorization algorithm to vectorize the background of the raster tif data to obtain vector shapefile data, specifically including:

[0036] S301, using a raster-to-vector algorithm to vectorize pixels with a raster value of 255 from the orthophoto, to obtain shapefiles data of the peripheral area of ​​the building image.

[0037] S4. Reverse vector clipping of the above shapefile to obtain high-precision vector building outline data, such as Figure 5As shown, specifically including;

[0038] S401, using a vector clipping tool, reversely clipping the shapefile obtained in S3 to obtain vector data of the building image area outline;

[0039] S402, constructing a buffer for the contour vector data, Figure 6 A 30cm buffer is constructed in the image to optimize the contour wrapping effect and obtain vector data that can completely surround the building model.

[0040] S5. Use geometric calculation tools to calculate and generate the center point of the contour;

[0041] S6, using the coordinate mapping of the center point in the three-dimensional model, extracting the three-dimensional building altitude corresponding to the xy longitude and latitude, and obtaining vector point data with the altitude;

[0042] S601. Use a spatial mapping algorithm to record the altitude of each building center point in the three-dimensional model and obtain the vector point coordinates of the altitude.

[0043] S7, spatially track the outline data and the center point data to obtain the building outline data with height, such as Figure 7 Building vector outline with elevation shown extruded and loaded in 3D overlay.

[0044] S701, using a spatial tracking algorithm to process the building outline and center point, so that the height data attached to the center point of each outline can also be matched to the outline, and obtain refined vector data that can wrap the building, such as Figure 7 shown.

[0045] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for batch extraction of individual building outlines based on real-scene three-dimensional models, characterized in that: These include: S1. Based on the real-life 3D model, the facade cutting technology is used to cut the osgb data and remove the redundant ground model to obtain the 3D model of the building; S2. Use the basic ortho output tool to produce ortho grid images for the cropped osgb model data to obtain grid tif data; S3, using a raster-to-vector algorithm to vectorize the background of the raster tif data to obtain vector shapefile data; S4, reverse vector clipping the shapefile to obtain high-precision vector building outline data; S5. Use geometric calculation tools to calculate and generate the center point of the contour; S6, using the coordinate mapping of the center point in the three-dimensional model, extracting the three-dimensional building altitude corresponding to the xy longitude and latitude, and obtaining vector point data with the altitude; S7. Perform spatial tracking on the outline data and the center point data to obtain building outline data with height.

2. The method for batch extracting individual building outlines based on real-scene three-dimensional models as claimed in claim 1 is characterized in that: The S1 specifically includes: S101, the ground and building altitudes of real-scene 3D data in different areas are different, and the real-scene 3D osgb data is divided into blocks to obtain multiple model data sets with relatively uniform ground altitudes; S102. Use the facade cropping tool to perform facade cropping on the above-mentioned block osgb model data. After adjusting the cropping height, perform the cropping operation to obtain the block model. According to the osgb data production rules, the entire osgb data and the scattered osgb data sets share a .xml file, and the file names will not be repeated, so the cropped block models can be directly merged into a folder to obtain the cropped and integrated osgb data of the block building three-dimensional model.

3. The method for batch extracting individual building outlines based on real-scene three-dimensional models as claimed in claim 1, characterized in that: The S2 specifically includes: S201. The production standard of orthophoto can refer to the model resolution. If the model resolution is 3cm, then the resolution of orthophoto can reach up to 3cm, and the contour extraction accuracy is ±3cm. S202. The grid background value of the ortho tif data can be set to 0 or 255, and finally an ortho tif image with a self-set resolution and a black or white background is obtained.

4. The method for batch extracting individual building outlines based on real-scene three-dimensional models as claimed in claim 1, characterized in that: The S3 specifically includes: S301, using a raster-to-vector algorithm to vectorize pixels with raster values ​​of 0 or 255 from the orthophoto, to obtain shapefiles data of the peripheral area of ​​the building image.

5. The method for batch extracting individual building outlines based on real-scene three-dimensional models as claimed in claim 1, characterized in that: The S4 specifically includes: S401, using a vector clipping tool, reversely clipping the shapefile obtained in S3 to obtain vector data of the building image area outline; S402: construct a buffer zone for the outline vector data, optimize the outline wrapping effect, and obtain vector data that can completely surround the building model.

6. The method for batch extracting individual building outlines based on real-scene three-dimensional models as claimed in claim 1, characterized in that: The S6 specifically includes: S601, using a spatial mapping algorithm to record the altitude of each building center point in the three-dimensional model, and obtain the vector point coordinates of the altitude.

7. The method for batch extracting individual building outlines based on real-scene three-dimensional models as claimed in claim 1, characterized in that: The S7 specifically includes: S701. Use a spatial tracking algorithm to process the building outline and center point, so that the height data attached to the center point of each outline can also be matched to the outline, and obtain refined vector data that can wrap the building.

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