KR101289885B1 - Apparatus and method for modeling building - Google Patents

Abstract

The building modeling apparatus for building buildings using aerial images includes a wall image acquisition unit and a wall image processing unit. The wall image acquisition unit receives the information of the 3D building model of the building through the aerial image, and acquires the wall texture image of the wall surface of each building using the information of the 3D building model. The wall image processing unit receives the wall texture image from the wall image acquisition unit, sets the texel image to correct the occlusion area included in the wall texture image, and synthesizes the texel image into the image of the occlusion area to generate the final wall image. .

Aerial image, wall, wall texture image, modeling, occlusion area, adjacent tree occlusion stencil image, adjacent wall occlusion stencil image

Description

Apparatus and method for modeling a building {APPARATUS AND METHOD FOR MODELING BUILDING}

The present invention relates to an apparatus and method for modeling a building, and more particularly, to an apparatus and method for acquiring and processing an image of a wall of a building from an aerial image when modeling a 3D building using an aerial image.

The present invention is derived from research carried out by the Ministry of Knowledge and Economy as a part of the IT original technology development project [Project Number: 2007-F-042-03, Project Name: Development of advanced technology for analysis of radio waves based on 3D GIS].

Recent three-dimensional spatial information is used to numerically represent the terrain or topography to continuously manage related information such as actual ground facilities and underground burial, and various application fields such as urban landscape planning, disaster management system, navigation and internet map service. Is being applied to.

The most important three-dimensional building model in the three-dimensional spatial information is to use the digital map and the floor information of the building director, the stereoscopic image with sensor modeling, the shadow or relief displacement of the building The method of acquiring a building model using only one image using the method, and the method of using light detection and ranging (LiDAR) data, which directly acquires height values of the points forming the ground surface with the laser distance measuring equipment mounted on the aircraft, have.

Among these methods, the method for acquiring the image of the building wall is to acquire only the geometric 3D information of the building, and then map arbitrary virtual images on the building wall or go out to the site to manually capture the images of the building wall and input them manually. Rather than using a stereoscopic stereoscopic image or a single image, the method of acquiring the 3D information of the building and directly acquiring the corresponding wall image of the building from the image is used mainly because it can model the building more quickly.

However, in this method of using images, it is difficult to acquire good quality images in buildings distributed near the main point of the image or in buildings where the wall direction does not coincide with the camera direction because the images must be photographed in the direction of the surface from above. In addition, it is difficult to obtain a better image of a building because the wall image is obscured by neighboring buildings and trees, or the shadow of the building itself acts as a serious noise factor in an urban dense area.

Therefore, there is a need for a technique for obtaining an image of a building wall surface in which the effect of noise is minimized quickly and realistically for modeling a building wall surface.

The technical problem to be achieved by the present invention relates to an apparatus and method for modeling a building that can obtain the image of the building wall surface from the aerial image when modeling the three-dimensional building using the aerial image.

In the device for building the building using the aerial image according to the characteristics of the present invention for achieving the above object,

Wall image acquisition unit for receiving the information of the three-dimensional building model for the building through the aerial image, and using the information of the three-dimensional building model to obtain a wall texture image of the wall surface of each building, and the wall surface Receives the wall texture image from an image acquisition unit, sets a texel image to correct the occlusion area included in the wall texture image, and combines the texel image with the image of the occlusion area to generate a final wall image. It includes an image processing unit.

In addition, in the building modeling method using the aerial image according to another feature of the present invention,

Receiving information of the 3D building model of the building through the aerial image, acquiring a wall texture image of the wall surface of the building using the information of the 3D building model, included in the wall texture image And setting a texel image for correcting the occluded region, and generating a final wall image by synthesizing the texel image with the image of the occluded region.

According to an embodiment of the present invention, when the 3D building is modeled using the aerial image, the image of the building wall is acquired from the aerial image, and the various noise elements present in the image of the building wall are corrected and restored to make it more realistic and quick. Model the building.

In addition, according to an embodiment of the present invention, since the image of the building wall surface is acquired from the aerial image, it is possible to model the building at a lower cost.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

1 is a view schematically showing an apparatus for modeling a building according to an embodiment of the present invention.

As shown in FIG. 1, the building modeling apparatus 100 for modeling a building according to an exemplary embodiment of the present invention includes an image receiving unit 110, a wall image obtaining unit 120, and a wall image processing unit 130. do.

The image receiving unit 110 receives the aerial image, and receives the information of the building model already built through the aerial image. The image receiver 110 transmits the information of the building model to the wall image acquisition unit 120. The building model information is constructed by acquiring the height of a building through shadow observation or undulation displacement observation of each three-dimensional building model in one aerial image, or three-dimensional information constructed by using two or more stereoscopic images. Since the construction method of the 3D information is a known technique, a detailed description thereof will be omitted.

The wall image obtaining unit 120 receives the information of the building model from the image receiving unit 110. The wall image acquisition unit 120 acquires the wall texture image of each wall surface of the building model through the 2D reverse projection and transmits the information of the 3D building model to the wall image processing unit 130. Here, the wall texture image is a two-dimensional image of the building wall obtained through the information of the building model in the aerial image. At this time, when acquiring the wall texture image of the same building model using a plurality of aerial images, the wall texture image is set by determining the validity of the wall image of the building model according to the shooting attitude of the building model, so the optimal wall texture image is obtained. Can be screened.

The wall image processing unit 130 receives the wall texture image acquired from the wall image acquisition unit 120, and corrects and restores noise elements included in the wall texture image to generate a final wall image. Noise components include elements such as shadows of the walls themselves, occlusion areas of adjacent trees (hereinafter referred to as "adjacent trees"), and occlusion areas by adjacent walls (hereinafter called "adjacent wall surfaces"). The explanation is described later.

In detail, the wall image processing unit 130 includes a shadow correcting unit 131, a closed area detecting unit 132, a texel image setting unit 133, and a final image generating unit 134.

The shadow correction unit 131 performs shadow correction to minimize the shadow effect of the wall surface in the wall texture image.

The occlusion area detector 132 detects an adjacent tree occlusion area and an adjacent wall occlusion area by receiving the wall texture image on which the shadow correction is performed by the shadow correction part 131. The occlusion area detector 132 displays pixels corresponding to the adjacent tree occlusion areas to generate an adjacent tree occlusion stencil image. The occlusion area detector 132 calculates an overlapping area by using wall texture area information of the wall and the adjacent wall surface adjacent to the wall, and generates an adjacent wall stencil image by displaying the overlapping area. The occlusion area detector 132 synthesizes the adjacent tree occlusion stencil image and the adjacent wall stencil image to generate a merge occlusion stencil image.

The texel image setting unit 133 detects an upper limit line of the occlusion area in the merge occlusion stencil image, sets the upper limit line of the detected occlusion area as the base line BL, and moves upward from the search base line BL. Set the texel image while moving in the direction where no occlusion area exists. Here, a texel (texture element) image is the smallest unit that constitutes texture data in computer graphics, and each element of an image is used to construct a texture mapping using an image on a polygon. Also do. The texel image referred to in the embodiment of the present invention is an image set as a part of the building wall in the upper direction of the upper limit of the occlusion area to restore the occlusion area of the building wall. A detailed description of the setting of the texel image will be described later.

The final image generator 134 generates a final wall image by synthesizing the texel image to the occlusion area of the merged occlusion stencil image.

Hereinafter, a method of generating a final wall image by correcting and processing a noise element included in a wall texture image will be described in detail with reference to FIGS. 2 to 14.

FIG. 2 is a diagram illustrating a procedure of acquiring a wall texture image by a wall image acquisition unit of the building modeling apparatus illustrated in FIG. 1. FIG. 3 is a diagram illustrating an example for explaining a method of calculating texture validity in the wall image obtaining unit of FIG. 2. 4A to 4D are diagrams illustrating an example of setting a wall texture image in the wall image acquisition unit of FIG. 2.

As shown in FIG. 2, the wall image obtaining unit 120 of the building modeling apparatus 100 according to the exemplary embodiment of the present invention receives the information of the building model from the image receiving unit 110 (S200). The wall image acquisition unit 120 calculates a wall texture area on the image of each wall of the building model through two-dimensional inverse projection of information of the three-dimensional building model (S210). The wall texture area according to the embodiment of the present invention is a modified rectangular polygonal shape formed by retroprojecting a three-dimensional building wall surface of a rectangular shape onto an image. At this time, since the information of the building model is received from the plurality of aerial images, different wall images of the corresponding wall surface are acquired from each image on the same wall surface. The higher the quality of the wall image, the more difficult it is to acquire a high quality wall image, even if it is far from the pub, as the direction of the wall is different from the direction of the camera.

)과 벽면의 중심으로부터 영상의 주점을 향하는 벡터(

)와의 관계로 텍스쳐 유효도(Validation Factor: VF)를 계산하며, 텍스쳐 유효도는 수학식 1과 같다(S220).The wall image acquisition unit 120 normal vector of each wall constituting the building in the wall texture area on the image for each wall of the building model as shown in Figure 3 to determine the validity of the building wall image according to the shooting position (

) And the vector from the center of the wall toward the pub of the image

The texture validity (VF) is calculated in relation to the above, and the texture validity is equal to Equation 1 (S220).

The wall image acquisition unit 120 selects a wall image having the maximum texture validity (VF) in each image when multiple images are available for the same wall and resamples the wall texture image into a rectangular image. To transmit to the wall image processing unit 130 (S230).

For example, the wall image acquisition unit 120 calculates the texture validity (VF) of the front surface of the shaded building for the same building observed in several aerial images having different shooting positions and postures shown in FIGS. 4A to 4D. Calculate using Equation 1. The wall image acquisition unit 120 selects the wall image of FIG. 4C having the maximum texture validity (VF) of the building from FIGS. 4A to 4D and resamples the wall texture image into a rectangular image to form the wall image processing unit 130. To pass).

5 is a diagram illustrating an example of noise elements generated in a wall texture image according to an exemplary embodiment of the present invention.

As shown in FIG. 5, in the embodiment of the present invention, noise components generated in the wall texture image include a self-shading wall, an adjacent tree blockage, an adjacent wall blockage area, and an adjacent shadow.

)와 태양(600)의 방위각의 단위 벡터(

)가 마주하는 각이 소정 범위 이상을 벗어나게 되어 벽면 자체의 그림자에 의해 이미지가 훼손되는 것이며, 이러한 벽면을 셀프 쉐이딩 벽면이라고 한다.Self shading is the normal vector of the wall 500

) And the unit vector of the azimuth of the sun 600 (

The angles facing each other are outside the predetermined range and the image is damaged by the shadow of the wall itself. Such a wall is called a self-shading wall.

Adjacent tree occlusion area is the occlusion is generated by the tree 700 adjacent to the wall surface 500, the adjacent wall occlusion area is the occlusion is generated by the wall surface 800 adjacent to the wall surface 500. . In this case, the occlusion area is one of noise elements, and is an area represented by an abnormally damaged image due to an obstacle element, for example, the tree 700 and the adjacent wall 800.

Adjacent shadows are images that are damaged by shadows generated by the wall surface 800 adjacent to the wall surface 500.

FIG. 6 is a diagram illustrating a procedure of generating a final wall texture image by a wall image processing unit of the building modeling apparatus illustrated in FIG. 1.

As shown in FIG. 6, the wall image processing unit 130 of the building modeling apparatus 100 according to an exemplary embodiment of the present invention receives a wall texture image from the wall image acquisition unit 120. The shadow correction unit 131 of the wall image processing unit 130 performs shadow correction to minimize the shadow effect of the corresponding wall surface in the wall texture image (S600). In addition, since the occlusion area detector 132 may take a long time to perform the occlusion area extraction and texture restoration work, the occlusion area detection unit 132 does not collectively perform corrections on all buildings and walls, and provides information such as the height of the building or texture validity. First, it is determined whether the object is a wall to be processed (S610).

When the wall surface of the building is a wall to be processed, the occlusion area detector 132 detects an adjacent tree occlusion area included in the wall surface (S620). The occlusion area detection unit 132 detects an adjacent wall surface occlusion area (S630). The texel image setting unit 133 sets the texel image in consideration of the detected adjacent tree occlusion area and the adjacent wall occlusion area. The final image generator 134 generates a final wall image by repeatedly synthesizing the texel image in the adjacent tree occlusion area and the adjacent wall occlusion area (S640).

On the other hand, if the wall surface of the building of the building is not the target wall surface, the wall image processing unit 130 does not perform the process of extracting and restoring the occlusion area.

7 is a flowchart illustrating a method of performing shadow correction in the shadow correcting unit of the wall image processing unit of FIG. 1.

As shown in FIG. 7, the shadow correcting unit 131 of the wall image processing unit 130 receives the wall texture image from the wall image acquisition unit 120 in the building modeling apparatus 100 according to the embodiment of the present invention. In operation S601, it is determined whether the corresponding wall surface of the transferred wall texture image is a self-shading wall surface by using an inner product calculation between the normal vector of the wall surface and the azimuth angle of the sun (S602).

If the wall surface is a self-shading wall surface, the shadow correction unit 131 performs self-shading correction using the normal vector of the wall surface and the azimuth angle of the sun (S603).

On the other hand, if the wall is not a self-shading wall, the shadow correction unit 131 determines that the shadow of the adjacent wall is generated on the wall by the geometric arrangement between the sun, the wall and the adjacent wall, and then, through the image processing technique, The shadow area of the adjacent wall surface is detected (S604). The shadow correction unit 131 performs shadow area correction only on the detected shadow area of the adjacent wall surface (S605).

8 is a flowchart illustrating a method of detecting an adjacent tree occlusion area by the occlusion area detection part of the wall image processing part shown in FIG. 1.

As shown in FIG. 8, in the building modeling apparatus 100 according to an exemplary embodiment of the present invention, when the shadow correction is completed, the occlusion area detector 132 of the wall image processing unit 130 displays the wall texture image of which shadow correction is completed. It receives (S621). The occlusion area detector 132 searches for a pixel for the tree in order to detect the occlusion area by an adjacent tree (S622). That is, the occlusion area detector 132 searches for pixels for trees using a method of using color information or a method of using texture entropy to search for pixels for trees.

The occlusion area detection unit 132 sets the pixels for the extracted trees to "0", and sets the remaining pixels to "1" so that the occlusion stencil image by the adjacent trees (hereinafter, referred to as "neighboring tree occlusion stencil image") Produce (S623). At this time, the occlusion stencil image includes occlusion information of the same size as the input wall texture image. In the embodiment of the present invention, the pixels for the tree are set to "0", and the remaining pixels are set to "1". However, the present invention is not limited thereto, and the pixels for the tree are set to "1" and the remaining pixels are set to "1". It can also be set to "0".

9 is a flowchart illustrating a method of detecting an adjacent wall occlusion area by the occlusion area detection part of the wall image processing part shown in FIG. 1.

As shown in FIG. 9, in the building modeling apparatus 100 according to the exemplary embodiment of the present invention, the occlusion area detecting unit 132 of the wall image processing unit 130 is connected to the wall surface and the adjacent wall surface from the wall image obtaining unit 120. Information about the wall texture area is received and received (S631).

The occlusion area detector 132 calculates an overlapping area between the wall surface texture area information on the wall surface and the adjacent wall surface (S632). That is, the occlusion area detector 132 receives the wall texture area information of the adjacent wall along with the wall texture area information of the corresponding wall and calculates an overlapping area through intersection between the texture areas. At this time, the occlusion area detector 132 minimizes the search time by limiting the search range by searching only the wall texture areas of the adjacent wall in the main direction from the wall for efficient search of the wall texture area of the adjacent wall.

The occlusion area detector 132 sets pixels corresponding to the calculated overlap area to "0", and sets non-overlapping pixels to "1" to block the occlusion stencil image by the adjacent wall surface (hereinafter, the "adjacent wall occlusion stencil image"). "," (S633). In the exemplary embodiment of the present invention, pixels corresponding to the overlapping region are set to "0", and pixels not overlapping are set to "1", but the present invention is not limited thereto, and the pixels corresponding to the overlapping region are set to "1". It is also possible to set non-overlapping pixels to "0". At this time, the occlusion area detecting unit 132 calculates an overlapping area between the wall texture area of the wall and the adjacent wall while the wall texture image has not yet been resampled in the form of a rectangle. Perform resampling in the form.

FIG. 10 is a flowchart illustrating a method of generating a final wall image by the texel image setting unit and the final image generating unit of the wall image processing unit of FIG. 1. 11 is a diagram illustrating an example of a merged occlusion stencil image according to an embodiment of the present invention. FIG. 12 is a diagram illustrating an example of setting a texel image in the texel image setting unit of the wall image processing unit illustrated in FIG. 1. FIG. 13 is a diagram illustrating an example of a final wall image of restoring an adjacent tree occlusion area according to an exemplary embodiment of the present invention. FIG. 14 is a view showing an example of the final wall image restored the adjacent wall occlusion area in accordance with an embodiment of the present invention.

As shown in FIG. 10, the occlusion area detection unit 132 of the wall image processing unit 130 according to an embodiment of the present invention merges the adjacent tree occlusion stencil image and the adjacent wall occlusion stencil image to generate a merge occlusion stencil image. An example of the merged occlusion stencil image is shown in FIG. 11 (S641).

10 and 12, the texel image setting unit 133 may have a merge occlusion stencil.

The upper limit line of the occlusion area is detected in an unknown manner, and the upper limit line of the detected occlusion area is set as a search reference line (Base Line, BL) (S642). Here, the upper limit of the occlusion area is set to the uppermost end of the occlusion area in the merge occlusion stencil image.

The texel image setting unit 133 sets the pixel line segment in which the gradient in the y-axis direction of the line segment of the pixel is maximized while moving upward from the search reference line BL as the texel lower line (LL). (S643). In this case, the degree of change in the y-axis direction may be calculated using a differential operator such as a horizontal prewitt operator.

The texel image setting unit 133 sets a texel upper line UL that has a maximum cross-correlation value with the texel lower limit LL in the upward direction from the texel lower limit line LL (S644). ). In this case, the mask is set in a predetermined range around the texel upper limit UL and the un-normalized cross-correlation is applied to all pixels in the mask to increase the matching accuracy. It calculates by (2). That is, the texel image setting unit 133 calculates the cross-correlation while moving up one line from the texel lower limit line LL, and sets the d-th line having the maximum irregular cross correlation as the texel upper limit UL. do.

Here, i is an index representing a pixel in the mask, and d is an index of a line to calculate the cross correlation.

The texel image setting unit 133 sets a piece of the image from the texel lower limit line LL to the texel upper limit UL as a texel image for the corresponding wall texture image and transmits the fragment to the final image generator (S645).

The final image generator 134 receives the texel image from the texel image setting unit 133 and repeatedly synthesizes the texels set in the occlusion area below the texel lower limit line LL to block the occlusion area and the adjacent wall occlusion area by the adjacent trees. Reconstructing to generate a final wall image (S646).

For example, as shown in FIG. 13, the texel image setting unit 133 is a texel for the wall texture image when the occluded area by adjacent trees exists in the wall texture image of the building in the merged occlusion stencil image. Set the image. The final image generator 134 repeatedly synthesizes the texel image in the occluded area by the adjacent trees to restore the occluded area by the adjacent trees to generate the final wall image.

As another example, as shown in FIG. 14, the texel image setting unit 133 sets the texel image of the wall texture image when the adjacent wall occlusion area exists in the wall texture image of the building in the merge occlusion stencil image. do. The final image generator 134 generates a final wall image by reconstructing the adjacent wall occlusion area by repeatedly synthesizing the texel image set corresponding to the adjacent wall occlusion area.

As such, the building modeling apparatus 100 according to an exemplary embodiment of the present invention sets a wall texture image of a corresponding building from information of a 3D building model of an aerial image when modeling a 3D building using an aerial image, and sets a wall texture. It is possible to model the building more realistically and quickly by processing the image and repeatedly synthesizing the set texel image to generate the final wall image with the minimum noise component. And since the image of the building wall is acquired from the aerial image, the building can be modeled at a lower cost.

The embodiments of the present invention described above are not implemented only by the apparatus and method, but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

1 is a view schematically showing an apparatus for modeling a building according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a procedure of acquiring a wall texture image by a wall image acquisition unit of the building modeling apparatus illustrated in FIG. 1.

FIG. 3 is a diagram illustrating an example for explaining a method of calculating texture validity in the wall image obtaining unit of FIG. 2.

4A to 4D are diagrams illustrating an example of setting a wall texture image in the wall image acquisition unit of FIG. 2.

5 is a diagram illustrating an example of noise elements generated in a wall texture image according to an exemplary embodiment of the present invention.

FIG. 6 is a diagram illustrating a procedure of generating a final wall texture image by a wall image processing unit of the building modeling apparatus illustrated in FIG. 1.

7 is a flowchart illustrating a method of performing shadow correction in the shadow correcting unit of the wall image processing unit of FIG. 1.

8 is a flowchart illustrating a method of detecting an adjacent tree occlusion area by the occlusion area detection part of the wall image processing part shown in FIG. 1.

9 is a flowchart illustrating a method of detecting an adjacent wall occlusion area by the occlusion area detection part of the wall image processing part shown in FIG. 1.

FIG. 10 is a flowchart illustrating a method of generating a final wall image by the texel image setting unit and the final image generating unit of the wall image processing unit shown in FIG. 1.

11 is a diagram illustrating an example of a merged occlusion stencil image according to an embodiment of the present invention.

FIG. 12 is a diagram illustrating an example of setting a texel image in the texel image setting unit of the wall image processing unit illustrated in FIG. 1.

FIG. 13 is a diagram illustrating an example of a final wall image of restoring an adjacent tree occlusion area according to an exemplary embodiment of the present invention. FIG.

14 is a view showing an example of the final wall image restored the adjacent wall occlusion area in accordance with an embodiment of the present invention.

Claims (12)

In the device for modeling buildings using aerial images, A wall image acquisition unit which receives information of a 3D building model of the building through the aerial image, and acquires a wall texture image of the wall surface of each building using the information of the 3D building model, and The wall texture image is received from the wall image acquisition unit, a texel image is set to correct the occlusion area included in the wall texture image, and the final wall image is generated by combining the texel image with the image of the occlusion area. Wall image processing unit Building modeling device comprising a. The method of claim 1, The wall image acquisition unit, Computing the wall texture area for the wall surface of the building through the two-dimensional reverse projection of the information of the three-dimensional building model, and obtains the wall texture image by calculating the texture effectiveness of the wall surface of the building in the wall texture area Building modeling device. 3. The method of claim 2, The texture validity is Building modeling apparatus is calculated using the normal vector of the wall surface and the vector toward the principal point of the image from the center of the wall surface. 3. The method of claim 2, The wall image processing unit, A shadow correction unit for performing shadow correction on the wall texture image; An occlusion area detector for detecting the occlusion area by determining whether a wall surface of the wall texture image is to be processed; A texel image setting unit which generates the texel image to correct the occlusion area, and The final image generator for generating the final wall image by synthesizing the texel image to the image of the occlusion area Building modeling device comprising a. 5. The method of claim 4, The occluded area includes an adjacent tree occlusion area and an adjacent wall occlusion area, The occlusion area detector, When the occlusion area is the adjacent tree occlusion area, a pixel corresponding to the adjacent tree is displayed to generate an adjacent tree occlusion stencil image. When the occlusion area is the adjacent wall occlusion area, a building that calculates an overlapping area by using wall texture area information of the wall surface and the adjacent wall surface adjacent to the wall, and displays the overlapping area to generate an adjacent wall stencil image. Modeling device. The method of claim 5, The texel image setting unit, And a composite occlusion stencil image by synthesizing the adjacent tree occlusion stencil image and the adjacent wall occlusion stencil image, and setting a portion of the merge occlusion stencil image not including the occlusion area as the texel image. In the method of building modeling using aerial image, Receiving information of a 3D building model of the building through the aerial image; Acquiring a wall texture image of the wall surface of the building using the information of the 3D building model; Setting a texel image for correcting the occlusion area included in the wall texture image, and Generating a final wall image by synthesizing the texel image with the image of the occlusion area Building modeling method comprising a. The method of claim 7, wherein Acquiring the wall texture image, Calculating a wall texture area of the wall surface of the building through two-dimensional back projection of information of the three-dimensional building model, and And calculating the texture validity of the wall surface of the building in the wall texture area to obtain the wall texture image. The method of claim 7, wherein Setting the texel image, Correcting a shadow of the wall texture image; Detecting the occlusion area by determining whether a wall surface of the wall texture image is a processing object, and Generating the texel image for correcting the occlusion area Building modeling method comprising a. 10. The method of claim 9, The occlusion area includes a tree occlusion area and an adjacent wall occlusion area. The method of claim 10, Detecting the occlusion area, Generating the adjacent tree occlusion stencil image by displaying a pixel corresponding to the adjacent tree when the occlusion area is the adjacent tree occlusion area, and When the occlusion area is the adjacent wall occlusion area, an overlapping area is calculated by using wall texture area information of the wall surface and the adjacent wall surface adjacent to the wall, and the overlapping area is displayed to generate an adjacent wall stencil image. Building modeling method comprising a. 12. The method of claim 11, Generating the texel image, Synthesizing the adjacent tree occlusion stencil image and the adjacent wall stencil image to generate a merged occlusion stencil image; and And setting a portion of the merged occlusion stencil image not included in the occlusion region as the texel image.

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