KR100782152B1 - A method of acquiring three-dimensional data of a building from aerial photographs DX to produce a three-dimensional digital map - Google Patents

Abstract

 Disclosed is a method of obtaining 3D data of a building from an aerial photograph DB for producing a 3D digital map. The method for acquiring 3D data of a building from the aerial photograph DB may include a photographing point, a reference point, a first lower point, a first projection point, and a second projection of an aerial photo on a computer equipped with a 3D data calculation program. A method for acquiring three-dimensional data of a building from an aerial photo DB including coordinates for a point, the method comprising: a photographing point, a reference point, a first lower point for a specific building, a first projection point, and an aerial photo from the aerial photo DB; Extracting coordinates for the second projection point, respectively; Calculating coordinates for a second lower end point, a first upper end point, and a second upper end point of the specific building by using the extracted coordinates, respectively; And coordinates for the first lower end point, the first projection point, and the second projection point of the specific building, and coordinates for the calculated second lower point, the first upper point, and the second upper point of the specific building. The step of storing in the DB.

Description

Method for Obtaining 3-Dimensional Building Data From Aerial Photograph DB}

The present invention relates to a three-dimensional digital map of a geographic information system, and more particularly, to a method for obtaining three-dimensional data of a building from an aerial photograph DB to produce a three-dimensional digital map.

In recent years, interest and use of geographic information systems are rapidly increasing in various sectors of society. Geographic Information System (GIS) is a computer-based system that uses and manages geographic data to solve space related problems. Even when GIS was first developed in the early 1960s, GIS was nothing more than a computer-based program for processing map data. Today, however, GIS is not only one of the most important academic research fields in itself, but is also actively applied to various sectors of society in combination with the latest Information Technology (IT).

The basic characteristic of GIS is that it can handle attribute information related to the location of objects in spatial, ie geographic space. Maps are the most efficient way of indicating the locations and properties of spatially distributed objects. Therefore, the most basic data in GIS construction is digital map. Numerical maps, unlike classical paper maps, are indexed by interpreting and numerically editing various terrain data obtained from survey maps, aerial photographs, and satellite images.

Specifically, the process of constructing a digital map goes through several complex processes. First, the paper map is digitized or scanned to form the resin map, and then various input errors are corrected. After converting the coordinates to the actual coordinate system according to the user's purpose through coordinate transformation, a topological structure is established to grasp the mutual position and correlation between spatial objects. Subsequently, the attribute data related to each figure data is inputted into the digital map which has established the topological structure.

However, the conventional digital maps are mostly limited to expressing two-dimensional geographic information. Accordingly, interest in the production of 3D digital maps expressing 3D geographic information is increasing. In order to produce a 3D digital map, a process of acquiring 3D data must first be performed. Various methods have been proposed in this regard.

In order to solve the above problems, an object of the present invention is to provide a method that can easily obtain the three-dimensional data of the building using the aerial photo.

In order to solve this problem, the present invention, in a computer equipped with a three-dimensional data calculation program, coordinates for the shooting point, the reference point, the first lower point of the building, the first projection point and the second projection point of the aerial photograph A method for acquiring three-dimensional data of a building from an aerial photo DB, comprising: a photographing point, a reference point, a first lower point, a first projection point, and a second projection point of an aerial photo from the aerial photo DB; Extracting coordinates for each; Calculating coordinates for a second lower end point, a first upper end point, and a second upper end point of the specific building by using the extracted coordinates, respectively; And coordinates for the first lower end point, the first projection point, and the second projection point of the specific building, and coordinates for the calculated second lower point, the first upper point, and the second upper point of the specific building. It provides a method for acquiring three-dimensional data of a building from an aerial photo DB comprising the step of storing in the DB.

In the method for acquiring three-dimensional data of a building from an aerial photo DB according to the present invention, the coordinates of the photographing point are (x, y, z), the coordinates of the reference point (x, y, 0), and the first The coordinates of the lower point (x + a, y + a ', 0), the coordinates of the second lower point (x + a + l, y + a' + l ', 0), and the coordinates of the first upper point. Coordinates (x + a, y + a ', h), coordinates of the second upper point (x + a + l, y + a' + l ', h), and coordinates of the first projection point ( x + a + b, y + a '+ b', 0), and the coordinates of the second projection point are (x + a + b + c, y + a '+ b' + c ', 0). , Wherein the calculating step is

Calculates the value of "h" by

Calculates the value "l" by

It is possible to calculate the value of "l '".

According to the present invention, the three-dimensional data can be easily obtained for all buildings on the aerial photograph, and the three-dimensional data thus obtained can be effectively used for the production of the three-dimensional digital map.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technologies that are well known in the art to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly communicate without obscure the core of the present invention by omitting unnecessary description.

1 is an exemplary configuration diagram of a system for performing a method of obtaining 3D data of a building from an aerial photograph DB according to the present invention.

Referring to FIG. 1, the system 10 used to obtain 3D data on a building from an aerial photo includes an aerial photo DB 11, a building data DB 12, a UI unit 13, and an extraction unit 14. , A calculator 15, and a controller 16. It is preferable to understand that the method of obtaining 3D data of a building from an aerial photograph DB according to the present invention is executed on a computer equipped with a 3D data calculation program.

The aerial photograph DB 11 stores a plurality of aerial photographs and coordinate values for photographing points and reference points of each aerial photograph. The shooting point refers to the point where the aerial photograph is taken, and the reference point refers to the point where the height of the shooting point is removed, that is, the ground point vertically downward from the shooting point. In addition, the aerial photograph DB 11 stores coordinate values of the first lower end point, the first projection point, and the second projection point of the building included in each aerial photograph. Coordinate values of the first lower end point, the first projection point, and the second projection point of the building may be obtained by a conventional drawing operation. That is, after acquiring the coordinate values by surveying the reference point of the aerial photograph, the coordinate values of the first lower end point, the first projection point, and the second projection point of the specific building located on the anti-photographic image are identified using the drawing device based on the coordinates. do.

The building data DB 12 stores three-dimensional data of buildings included in individual aerial photographs. The three-dimensional data of each building has coordinate values such as first and second lower points, first and second upper points, first and second projection points, and among them, the first lower point and the first and second projections. The coordinate values for the points are already included in the aerial photograph, but the coordinate values for the second lower point and the first and second upper points are obtained through the calculation process of the present invention. These are also mentioned later.

The UI unit 13 collectively refers to an input device, a display device, and the like in charge of a user interface. The input device is a keyboard, a mouse, or the like, and receives a user's input to generate a corresponding input signal. The display device is a monitor or the like and visually outputs a process of the system.

The extraction unit 14 approaches the aerial photograph DB 11 under the control of the controller 16, and extracts necessary coordinate values from the necessary aerial photograph. The extracted coordinate values are sent to the calculator 15.

The calculation unit 15 calculates three-dimensional data of the building by using the coordinate values extracted by the extraction unit 14 under the control of the control unit 16, and stores the calculated data in the building data DB 12.

The controller 16 controls the operation of the UI unit 13 and controls data input / output to the aerial photograph DB 11 and the building data DB 12. In addition, the controller 16 controls the operations of the extractor 14 and the calculator 15.

Next, a method for obtaining building 3D data using aerial photographs will be described. 2 is a view for explaining a method for obtaining three-dimensional data of the building from the aerial photo DB according to the present invention.

As shown in (a) of FIG. 2, it is assumed that aerial photographing is performed on a specific building 20. In reality, the building 20 exists in three dimensions, but the image 21 is represented in the aerial photograph in two dimensions as shown in FIG.

In FIG. 2, the coordinate of the photographing point P is referred to as (x, 0, z) and the coordinate of the reference point S is referred to as (x, 0, 0). In addition, the coordinates of the first lower point A in the building 20 are (x + a, 0, 0), the coordinates of the second lower point B are (x + a + l, 0, 0), and the first upper point C. The coordinates of (x + a, 0, h), the coordinates of the second upper point D (x + a + l, 0, h), and the coordinates of the first projection point E (x + a + b, 0, 0), the coordinate of the second projection point F is called (x + a + b + c, 0, 0).

At this time, the coordinate of the photographing point P is a value which is predetermined at the time of photography of the aerial photograph, and the coordinate of the reference point S can be known from the coordinate of the photographing point P. In addition, the coordinates of the first lower end point A, the first projection point E, and the second projection point F can be known from the building image 21 shown in the aerial photograph, respectively. Therefore, the present invention obtains the coordinate values of the second lower point B, the first upper point C, and the second upper point D, which are the remaining coordinate values, from the known coordinate values. That is, the present invention calculates the length l and the height h of the building 20. For simplicity of representation and calculations, it is assumed herein that each of the points is on the x-axis (ie, the y value is zero).

1 and 2, the building 3D data acquisition method will be described in detail. First, the controller 16 receives the user input from the input device of the UI unit 13 and drives the extraction unit 14. The extraction unit 14 accesses the aerial photographic DB 11 under the control of the control unit 16, retrieves necessary data, and sends the necessary data to the operation unit 15. At this time, the extracted data is taken by the aerial photographing point P (x, 0, z), reference point S (x, 0, 0), first lower point A (x + a, 0, 0) of the building 20, One projection point E (x + a + b, 0, 0) and a second projection point F (x + a + b + c, 0, 0).

Subsequently, the calculation unit 15 calculates the three-dimensional data of the building by using the data received from the extraction unit 14 under the control of the control unit 16, and includes the calculated data to generate the three-dimensional building data including the building data DB 12. ). The data calculated by the calculating unit 15 includes the second lower point B (x + a + l, 0, 0), the first upper point C (x + a, 0, h), and the second upper point of the building 20. D (x + a + l, 0, h). Hereinafter, the calculation process of the calculating part 15 is demonstrated concretely.

First, the calculation unit 15 calculates an unknown value of "h" using Equation 1 below.

Equation 1 is derived from the relationship between the triangle PSE and the triangle CAE in FIG. Subsequently, the calculation unit 15 calculates the remaining unknown "l" value by using Equation 2 below.

Equation 2 is derived from the relationship between the triangle PSF and the triangle PTD in FIG. As described above, the second lower point B (x + a + l, 0, 0), the first upper point C (x + a, 0, h), and the second value are obtained by obtaining the values of “h” and “l”. The value of the upper point D (x + a + l, 0, h) can be obtained. In conclusion, three-dimensional data of the building 20 is obtained from the two-dimensional data of the building image 21 of the aerial photograph.

The above description and calculations are based on the assumption that each point is on the x-axis, but the same principle can be applied to the more general case where each point is not on the x-axis (ie, the y value is non-zero). Hereinafter, a method of obtaining building 3D data in a more general case by applying the above principle will be described.

The coordinates of the shooting point P (x, y, z), the coordinates of the reference point S (x, y, 0), the coordinates of the first lower point A in the building (x + a, y + a ', 0), Coordinate of the second lower point B (x + a + l, y + a '+ l', 0), Coordinate of the first upper point C (x + a, y + a ', h), and second upper The coordinate of the point D is (x + a + l, y + a '+ l', h), and the coordinate of the first projection point E is (x + a + b, y + a '+ b', 0), The coordinate of the two projection point F is called (x + a + b + c, y + a '+ b' + c ', 0).

In this case, the value "h" may be obtained using Equation 1 described above, and the value "l" may be obtained using Equation 2 described above. Meanwhile, another unknown value "l '" may be obtained using Equation 3 below.

As described above, the three-dimensional data can be obtained for all buildings on the aerial photograph, and the building three-dimensional data thus obtained can be effectively used for the production of the three-dimensional digital map.

So far, the method for obtaining building 3D data using aerial photographs according to the present invention has been described. In the present specification and drawings, preferred embodiments of the present invention have been disclosed, and although specific terms have been used, these are merely used in a general sense to easily explain the technical contents of the present invention and to help the understanding of the present invention. It is not intended to limit the scope. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

1 is an exemplary configuration of a system for performing a method for obtaining 3D data of a building from an aerial photograph DB according to the present invention.

Figure 2 is a view for explaining a method for obtaining three-dimensional data of the building from the aerial photo DB according to the present invention.

Claims (2)

Three-dimensional data of a building from an aerial photograph database including coordinates for the shooting point, the reference point, the first lower point of the building, the first projection point and the second projection point of the aerial photograph on a computer equipped with a three-dimensional data calculation program. In the method of obtaining, Extracting coordinates for a photographing point, a reference point, a first lower point, a first projection point, and a second projection point of an aerial photograph from the aerial photograph DB, respectively; Calculating coordinates for a second lower end point, a first upper end point, and a second upper end point of the specific building by using the extracted coordinates, respectively; And The coordinates for the first lower end point, the first projection point and the second projection point of the specific building and the coordinates for the calculated second lower point, the first upper point and the second upper point of the specific building are the building data DB. Obtaining three-dimensional data of the building from the aerial photo DB comprising the step of storing in. The method of claim 1, The coordinates of the photographing point (x, y, z), the coordinates of the reference point (x, y, 0), the coordinates of the first lower point (x + a, y + a ', 0), the first 2 coordinates of the lower point (x + a + l, y + a '+ l', 0), coordinates of the first upper point (x + a, y + a ', h), and the second upper point Coordinates of (x + a + l, y + a '+ l', h), coordinates of the first projection point of (x + a + b, y + a '+ b', 0), and the second When the coordinate of the projection point is (x + a + b + c, y + a '+ b' + c ', 0), The calculating step is the following equation

Calculates the value of "h" by

Calculates the value "l" by

And obtaining the 3D data of the building from the aerial photographic DB, characterized by calculating a value of "l '".

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