KR102017949B1 - Apparatus and method for calibrating camera using rectangular parallelepiped with led - Google Patents

Abstract

The present invention relates to a calibration device that performs calibration of a camera. According to one or more exemplary embodiments, a calibration device includes: a reference object having a body having a rectangular parallelepiped shape; And a calibration unit configured to perform calibration of the camera using an image of the camera photographing the reference object.

Description

Calibrating device and method of a camera using a rectangular parallelepiped with light emitting diodes {APPARATUS AND METHOD FOR CALIBRATING CAMERA USING RECTANGULAR PARALLELEPIPED WITH LED}

The present invention relates to a calibration apparatus and method for a camera using a rectangular parallelepiped with a light emitting diode.

The world that humans see with real eyes is three-dimensional. However, when this is captured by a camera, it is converted into a two-dimensional image. At this time, the position of each point in the three-dimensional world is located on the two-dimensional image is determined by the position and orientation of the camera at the time of taking the image in consideration of the geometric. However, the actual image is greatly influenced by mechanical parts inside the camera such as the lens used, the distance between the lens and the image sensor, and the angle between the lens and the image sensor. Therefore, when calculating the position where each point of the three-dimensional world is projected on the two-dimensional image or conversely restoring the three-dimensional spatial coordinates from the coordinates on the two-dimensional image, it is necessary to remove these internal factors to enable accurate calculation. Internal configuration information of the camera is not explicitly known except for expensive cameras, and external configuration information is difficult to measure except in special cases. The process of obtaining parameter values of these internal and external factors is called camera calibration.

This is a major technology issue in the field of computer vision, and a key element for Augmented Reality (AR), which is of increasing interest in recent years. Since augmented reality has to accurately superimpose a three-dimensional virtual object on a real world image, a calibration that can explain a transformation relationship between real world 3D spatial coordinates and coordinates of a 2D image acquired by a camera must be preceded. Since it should be applied to the real world, the calibration suitable for augmented reality should minimize the effects of environmental changes such as changes in lighting in the real world.

Various techniques have been proposed as camera calibration techniques, mainly using a single image of a precisely pre-configured calibration object or multiple images of a checker board of known size. However, a calibration technique using a general three-dimensional object has a problem of difficulty in manufacturing a three-dimensional object and expensive equipment. In addition, the calibration technique using a general two-dimensional object using a checker board or the like is difficult to contrast the white and the black region in a dark environment, it is difficult to accurately extract the intersection between the white and black areas, and a plurality of images are required for one camera.

The present invention is to provide a calibration device and method that is easy to manufacture an object to be photographed.

It is also an object of the present invention to provide a calibration apparatus and method capable of minimizing the influence of the lighting environment.

It is also an object of the present invention to provide a calibration apparatus and method capable of minimizing the number of images required.

The problem to be solved by the present invention is not limited thereto, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention provides a calibration device for performing the calibration of the camera. According to one embodiment, the calibration device includes: a reference object having a body having a rectangular parallelepiped shape; And a calibration unit configured to perform calibration of the camera using an image of the camera photographing the reference object.

The reference object may further include a light emitting member provided at each vertex of the body and generating light.

The light emitting member may be provided as a diffused light emitting diode (Diffused LED).

The calibration unit includes a light emitting member position detector for detecting a position of the light emitting member on the image; A quadrangle forming unit configured to form a quadrangle by connecting the light emitting members whose position is detected by the light emitting member position detector on the image; It may include a matrix calculator for obtaining a calibration matrix for each rectangle formed in the rectangle forming unit using a rectangle-based calibration technique.

The light emitting member position detector may include a filtering unit to filter noise on the image; The filtering unit may include a light emitting member center extracting unit for deriving a position of the center of the light emitting member on the image on which the filtering is performed.

The filtering unit filters the noise on the image using a Gaussian smoothing filtering technique, and the light emitting member center extracting unit filters the noise of the light emitting member on the image, which is filtered by the filtering unit using a binarization technique. The position of can be derived.

The quadrangle forming unit may include a polygonal forming unit which connects the outer light emitting members positioned at the outermost sides of the light emitting members on the image detected by the light emitting member position detecting unit to form polygons.

The polygonal forming unit connects the outer light emitting members sequentially, but forms a closed curve by forming the closed curve by connecting the outer light emitting member which is the starting point of the outer light emitting member to an end point, and whether the closed curve is a convex. The convexity determination may be performed, and the closed curve formation and the convexity determination may be performed by changing a connection order of the outer light emitting member of the outer light emitting member, and the closed curve determined as convex among the closed curves may be determined as the polygon. have.

The quadrangle forming unit may include a light emitting member number determining unit configured to determine the number of the light emitting members on the image; In addition to the sides of the polygon may further include an internal line segment extraction unit for extracting a line segment sharing a vanishing point with two or more of the sides of the light emitting member connecting the two light emitting members of the side as an internal segment.

The internal line segment extracting unit does not perform the extraction of the internal line segment when the number of light emitting members on the image is four, and when the number of light emitting members on the image is six and the vanishing point is three, two of the light emitting members are used. Of the light emitting members in the polygon and the outer light emitting members when the number of light emitting members on the image is 7 Among the line segments connecting one, a line segment sharing a vanishing point with two or more of the sides may be extracted as the internal line segment.

When the number of light emitting members on the image is six and the number of vanishing points is two, the internal line extracting unit may extract, as the internal line segments, a line segment connecting two light emitting members whose sides sharing each vanishing point cross each other. .

In addition, the present invention provides a calibration method for performing the calibration of the camera. According to an embodiment, the calibration method may include photographing a reference object having a rectangular parallelepiped shape with a camera and performing calibration of the camera using an image of the reference object captured by the camera, wherein each vertex of the reference object has light. A light emitting member for generating light is provided.

The light emitting member may be provided as a diffused light emitting diode (Diffused LED).

The calibration method comprises the steps of: detecting a position of a light emitting member on the image; Thereafter, forming a quadrangle by connecting the light emitting members on the image to each other; Subsequently, the method may include a matrix calculation step of obtaining a calibration matrix for each quadrangle formed in the quadrangle forming step by using a square-based calibration technique.

In the light emitting member position detection step, the noise on the image may be filtered using a Gaussian smoothing filtering technique, and the position of the central portion of the light emitting member on the filtered image may be derived by using a thresholding technique.

In the quadrangle forming step, a polygon forming step of forming a polygon by connecting the outer light emitting members positioned in the outermost part of each direction among the light emitting members on the image where the position is detected by the light emitting member position detection unit to each other, the polygon In the forming step, the outer light emitting members are sequentially connected to each other, but a closed curve is formed to form a closed curve by connecting the outer light emitting member which is a starting point among the outer light emitting members to an end point, and determining whether the closed curve is a convex. A convexity determination may be performed, and the closed curve formation and the convexity determination may be performed by changing a connection order of the outer light emitting member of the outer light emitting member, and the closed curve determined as convex among the closed curves may be determined as the polygon.

The quadrangle forming step may include: determining a number of light emitting members on the light emitting member; After the step of determining the number of light emitting members and forming the polygon, the line segment sharing the vanishing point with at least two sides of the light emitting member among the line segments connecting two light emitting members of the light emitting member in addition to the sides of the polygon is extracted as an internal line segment. The method may further include extracting an internal line segment, wherein, in the extracting of the internal line segment, if the number of light emitting members on the image is four, the extraction of the internal line segment is not performed and the number of light emitting members on the image is six and the vanishing point is two. In the individual case, a line segment connecting two light emitting members intersecting each other with the vanishing point is extracted as the internal line segment, and when the number of light emitting members on the image is six and the vanishing point is three, Two or more of the sides of a line segment connecting two light emitting members of the light emitting member A line segment that shares a true point is extracted as the inner line segment, and when the number of light emitting members on the image is seven, two or more of the sides and a vanishing point among the line segments connecting one of the light emitting member and the outer light emitting member in the polygon. A line segment that shares a may be extracted as the internal line segment.

The calibration apparatus and method according to an embodiment of the present invention makes it easy to manufacture an object to be photographed.

In addition, the calibration apparatus and method according to an embodiment of the present invention can minimize the influence of the lighting environment.

In addition, the calibration apparatus and method according to an embodiment of the present invention can minimize the number of images required.

1 is a view schematically showing a calibration device according to an embodiment of the present invention.
2 is a flowchart illustrating a calibration method according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating an example of a closed curve determined to be non-condex in the polygon forming unit of FIG. 1.
FIG. 4 is a diagram illustrating an example of a closed curve determined to be a condex in the polygon forming unit of FIG. 1.
5 is a diagram illustrating an example of a line segment not sharing a vanishing point when there are six light emitting members and three vanishing points appearing on an image.
6 is a diagram illustrating a line segment sharing a vanishing point with two or more sides of a polygon when six light emitting members and three vanishing points appear on an image.
FIG. 7 is a diagram illustrating a line segment connecting two light emitting members in which a side sharing one vanishing point and a side sharing another vanishing point cross each other when there are six light emitting members and two vanishing points appearing on the image.
8 is a diagram illustrating an example of a line segment not sharing a vanishing point when there are seven light emitting members displayed on an image.
9 is a diagram illustrating a line segment sharing vanishing points with two or more sides of a polygon when six light emitting members are displayed on an image.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The embodiments of the present invention can be modified in various forms, and the scope of the present invention should not be construed as being limited to the following embodiments. This embodiment is provided to more completely explain the present invention to those skilled in the art. Therefore, the shape of the elements in the drawings are exaggerated to emphasize a more clear description.

1 is a view schematically showing a calibration device 100 according to an embodiment of the present invention. Referring to FIG. 1, the calibration apparatus 100 performs calibration on the camera 200. According to an embodiment, the calibration device 100 includes a reference object 1000 and a calibration unit 2000.

The reference object 1000 includes a body 1100 and a light emitting member 1200. Body 1100 is provided in a cuboid shape. According to one embodiment, the body 1100 is provided in a cube shape. Since the body 1100 is provided in a rectangular parallelepiped shape in which each surface has a rectangular shape, a square base such as a coupled line cameras (CLC) technique or an image of absolute conic (IAC) technique using an image of the reference object 1000 is obtained. Calibration technique can be applied.

The light emitting member 1200 generates light during imaging of the reference object 1000 using the camera 200 to perform calibration, which will be described below. The light emitting member 1200 is provided at each vertex of the body 1100. Therefore, it is possible to minimize the influence of the brightness of the illumination during the imaging of the reference object 1000, it is easy to recognize each vertex of the body 1100 on the image. According to one embodiment, the light emitting member 1200 is provided as a diffused light emitting diode (Diffused LED). Therefore, since the light of the light emitting member 1200 is not concentrated in one direction, the recognition of the light emitting member 1200 located at a vertex located at a vertex of the vertex of the body 1000 that is exposed to the camera 200 is not recognized. Regardless of the relative position between the 1200 and the camera 200 is easy.

The calibration unit 2000 performs calibration of the camera 200 using an image of the camera 200 photographing the reference object 1000. According to an embodiment, the calibration unit 2000 includes a light emitting member position detector 2100, a quadrangle forming unit 2200, and a matrix calculator 2300.

The light emitting member position detector 2100 detects the position of the light emitting member 1200 on the image in which the camera 200 photographs the reference object 1000. According to an embodiment, the light emitting member position detector 2100 includes a filtering unit 2110 and a light emitting member center extracting unit 2120.

The filtering unit 2110 filters noise on an image of the camera 200 photographing the reference object 1000.

The light emitting member center extractor 2120 derives a position of the center of the light emitting member 1200 on the image in which the filtering unit 2110 performs the filtering.

The quadrangle forming unit 2200 forms a quadrangle by connecting the light emitting members whose positions are detected by the light emitting member position detector 2100 to each other on an image obtained by the camera 200 photographing the reference object 1000. According to an embodiment, the quadrangular forming unit 2200 includes a polygon forming unit 2210, a light emitting member number determining unit 2220, and an internal line segment extracting unit 2230.

The polygon forming unit 2210 forms a polygon by connecting the outer light emitting members positioned at the outermost sides of the light emitting members on the image where the position is detected by the light emitting member position detecting unit 2100 with each other.

The light emitting member number determiner 2220 determines the number of the light emitting members 1200 on the image of which the position is detected by the light emitting member position detector 2100.

The internal line segment extracting unit 2230 may be configured to include the line segment extracting unit 2230 among the line segments formed in the polygon forming unit 2210 among the line segments connecting two light emitting members 1200 among the light emitting members 1200 detected by the light emitting member position detecting unit 2100. A line segment sharing a vanishing point with at least two sides of the polygon is extracted as an internal segment.

The matrix calculator 2300 calculates a calibration matrix for each quadrangle formed in the quadrangle forming unit 2200 by using a square-based calibration technique.

Hereinafter, a calibration method according to an embodiment of the present invention will be described using the above-described calibration device 100 for convenience of description.

2 is a flowchart illustrating a calibration method according to an embodiment of the present invention. 1 and 2, the calibration method captures a rectangular parallelepiped reference object 1000 with the camera 200, and uses the image of the reference object 1000 captured by the camera 200 to display the camera 200. Perform calibration of. As described above, the light emitting member 1200 may be provided at each vertex of the reference object 1000. According to an embodiment, the calibration method includes a light emitting member position detecting step S10, a square forming step S20, and a matrix calculating step S30.

In the light emitting member position detecting step S10, the position of the light emitting member 1200 on the image of the reference object 1000 picked up by the camera 200 is detected. According to an embodiment, in the step of detecting the light emitting member (S10), the noise on the image is filtered, and the position of the center of the light emitting member 1200 on the filtered image is derived. For example, in the step of detecting the light emitting member position (S10), the filtering unit 2110 filters the noise on the image by using a Gaussian smoothing filtering technique, and the light emitting member center extracting unit 2120 is binarized ( By using a thresholding technique, the filtering unit 2110 derives the position of the central portion of the light emitting member 1200 on the filtered image. As described above, by filtering the noise on the image and deriving the position of the central portion of the light emitting member, it is possible to more accurately recognize the position of each vertex of the body 1100 on the image.

The quadrangular forming step S20 is performed after the light emitting member position detecting step S10. In the quadrangle forming step S20, the rectangles may be connected by connecting the light emitting members 1200 on the image detected in the light emitting member position detecting step S10 to apply the square-based calibration technique in the matrix calculation step S30, which will be described below. Form. According to an embodiment, the quadrangle forming step S20 includes a polygon forming step S21, a light emitting member number determining step S22, and an internal line segment extracting step S23. Each quadrangle formed in the quadrangle forming step S20 represents a surface appearing on the image among the surfaces of the reference object 1000.

3 is a diagram illustrating an example of a closed curve determined to be non-condex in the polygon forming unit 2210 of FIG. 1. FIG. 4 is a diagram illustrating an example of a closed curve determined to be a condex in the polygon forming unit 2210 of FIG. 1. 3 and 4, in the polygon forming step S21, the outer light emitting member 1210 positioned at the outermost side in each direction on the image among the light emitting members 1200 whose position is detected in the light emitting member position detecting step S10. ) To form a polygon. According to an embodiment, in the polygon forming step S21, the outer light emitting members 1210 are sequentially connected to each other, but a closed curve is formed to form a closed curve by connecting the outer light emitting members, which are the starting points of the outer light emitting members 1210, to the end points. Do this. In addition, in the polygon forming step S21, convexity determination is performed to determine whether the closed curve formed as described above is a convex. In the polygon forming step (S21), the closed curve formation and the convexity determination are performed by changing the connection order of the outer light emitting member 1210 when the closed curve is formed, and the closed curve determined as the convex among the formed closed curves is referred to as a reference object (1000). ) Is determined by the polygon representing the silhouette. For example, in the polygon forming step S21, the polygon forming unit 2210 of FIG. 1 performs the closed curve formation and the convexity determination, but the closed curve formed when the closed curve is formed is not the convex (in the case of FIG. 3). When the closed curve is formed by changing the connection order of the outer light emitting member 1210, and the closed curve is a convex (in case of FIG. 4), a polygon representing the silhouette of the reference object 1000 on the image of the closed curve determined as the convex. Decide on

Referring back to FIG. 2, the light emitting member number determining step S22 may be performed simultaneously with the polygon forming step S21. Alternatively, the light emitting member number determining step S22 may be performed before or after the polygon forming step S21. In the light emitting member number determining step S22, the number of the light emitting members 1200 detected in the light emitting member position detecting step S10 is determined. According to an embodiment of the present disclosure, the determining of the number of light emitting members S22 may be performed by the number of light emitting members determining unit 2220 of FIG. 1.

The internal line segment extraction step S23 is performed after the light emitting member number determining step S22 and the polygon forming step S21. In the internal line segment extraction step (S23), two of the sides of the polygon among the line segments other than the sides of the polygon formed in the polygon forming step (S21) among the line segments connecting the two light emitting members 1200 of the light emitting members 1200 on the image. The line segments sharing the above-described sides and vanishing points P1, P2, and P3 are extracted as internal line segments representing edges of the reference object 1000 on the image.

Since the reference object 1000 is provided as a rectangular parallelepiped, there may be four, six, or seven light emitting members 1200 appearing on the image captured by the camera 200.

According to an embodiment, in the internal line segment extraction step (S23), when the number of the light emitting members 1200 displayed on the image is four, only one surface of the reference object 1000 is visible on the image. No extraction of internal segments is performed.

In the case where the number of light emitting members 1200 shown in the image is six, two of the faces of the reference object 1000 are visible on the image, it is required to form two rectangles representing the two faces. . In this case, considering that the reference object 1000 is a rectangular parallelepiped, the vanishing points P1, P2, and P3 of the reference object 1000 on the image are two or three.

5 is a diagram illustrating an example of a line segment L1 that does not share the vanishing points P1, P2, and P3 when there are six light emitting members 1200 and three vanishing points P1, P2, and P3 shown in the image. . FIG. 6 is a diagram illustrating a line segment L2 sharing a vanishing point P3 and two or more sides of a polygon when there are six light emitting members 1200 and three vanishing points shown in the image. 5 and 6, according to an embodiment, when the internal line segment extraction step S23 includes six light emitting members 1200 and three vanishing points, the light emitting members 1200 appearing on the image. Among the line segments connecting two light emitting members among the line segments other than the sides of the polygon formed in the polygon forming step (S21), the line segment (L2) sharing the vanishing point (P3) and at least two sides of the polygon side as an internal segment Extract. For example, in the case of the line segment L1 of FIG. 5, since the sides and vanishing points P1, P2, and P3 of the polygon are not shared, they are not extracted as internal line segments. In the case of the line segment L2 of FIG. 6, since the two sides and the vanishing point P3 of the polygon are shared, the line segment L2 is extracted as an internal segment. Thereby, the rectangular parallelepiped shape of the reference object 1000 in which two surfaces were imaged by the camera 200 is completed.

FIG. 7 illustrates that when six light emitting members 1200 appear on an image and two vanishing points P1 and P2 are two, the sides sharing one vanishing point P1 and the sides sharing another vanishing point P2 are crossed. A line segment L3 connecting two light emitting members 1230a and 1230b is shown. Referring to FIG. 7, when six light emitting members 1200 are photographed and the viewpoint of the camera 200 is located at the center M of the center edge E1 on the image of the reference object 1000, the corner E1. ) And the edges E2 and E3 located on both sides of the edge E1 appear parallel to each other on the image, and thus do not share vanishing points with each other. Therefore, in this case, two vanishing points P1 and P2 are provided. According to an embodiment, in this case, in the internal line segment extraction step S23, two light emitting members 1230a and 1230b in which the side sharing one vanishing point P1 and the side sharing the other vanishing point P2 cross each other. Extract the line segment L3 connected as an internal segment. Thereby, the rectangular parallelepiped shape of the reference object 1000 in which two surfaces were imaged by the camera 200 is completed.

In the case where the number of light emitting members 1200 appearing on the image captured by the camera 200 is seven, three of the planes of the reference object 1000 are visible on the image. It is required to form In this case, considering that the reference object 1000 is a cuboid, the vanishing points P1, P2, and P3 of the reference object 1000 on the image are three.

FIG. 8 is a diagram illustrating an example of a line segment L4 that does not share vanishing points P1, P2, and P3 when seven light emitting members 1200 appear on an image. FIG. 9 is a diagram illustrating line segments L5, L6, and L7 that share vanishing points P1, P2, and P3 with two or more sides of a polygon when there are six light emitting members 1200. 8 and 9, according to an exemplary embodiment, in the internal line segment extraction step S23, when there are seven light emitting members 1200 displayed on the image, the light emitting member in the polygon formed in the polygon forming step S21 may be The line segments L5, L6, and L7 sharing the vanishing points P1, P2, and P3 of two or more sides of the polygon among the segments connecting one of the outer light emitting members 1210 and 1220 as internal segments. Extract. For example, in the case of line segment L4 of FIG. 8, since the sides and vanishing points P1, P2, and P3 of the polygon are not shared, they are not extracted as internal line segments. In the case of the line segments L5, L6, and L7 of FIG. 9, since the two sides and the vanishing points P1, P2, and P3 of the polygon are shared, they are extracted as internal line segments. Thereby, the rectangular parallelepiped shape of the reference object 1000 in which three surfaces were imaged by the camera 200 is completed.

The internal line segment extraction step S23 described above may be performed by the internal line segment extractor 2230 of FIG. 1.

Referring back to FIG. 2, the matrix calculation step S30 is performed after the square forming step S20. In the matrix calculation step (S30), a calibration matrix for each rectangle formed in the rectangle forming step (S20) is obtained by using a rectangle-based calibration technique. The matrix calculation step S30 may be performed by the matrix calculator 2300 of FIG. 1.

Referring back to FIG. 1, the calibration apparatus 100 may further include a reference object controller 3000. The reference object controller 3000 controls the light emitting member 1200. According to an embodiment of the present disclosure, the reference object controller 3000 turns on the light emitting member 1200 to perform calibration of the camera 200, and turns off the light emitting member 1200 when the calibration is completed. To control. In addition, the light emitting member 1200 may be provided to enable color change. For example, the light emitting member 1200 may be provided as a diffused RGB LED. In this case, the reference object controller 3000 may change the color of the light emitting member 1200 according to the calibration state. For example, the reference object controller 3000 receives information on calibration from the calibration unit 2000, and when the power of the light emitting member 1200 is turned on but the calibration is not performed according to the received information, the reference object controller 3000 is blue. For example, the light emitting member 1200 is controlled to generate light in red during calibration, and in green when calibration is completed. According to an embodiment of the present disclosure, the reference object controller 3000 is provided to the reference object 1000 and wirelessly transmits information to an apparatus (not shown) that supplies power to the light emitting member 1200 and changes the color of the light emitting member 1200. It is provided to transmit and receive.

The configuration and reference object controller 3000 that perform each function of the above-described calibration unit 2000 may be implemented in software in one computer. For example, the configuration and reference object controller 3000 that performs each function of the calibration unit 2000 may be implemented in software in a PC such as a Raspberry Pi.

Unlike the above description, the light emitting member 1200 may not be provided to the reference object 1000 provided as a rectangular parallelepiped. In this case, each surface of the reference object 1000 may be provided in a different color, so that each surface of the reference object 1000 may be recognized on the captured image. In this case, the calibration unit may obtain a calibration matrix for each face of each of the recognized faces using a square-based calibration technique. In this case, the above-described light emitting member position detecting step S10 and the square forming step S20 may be omitted.

In addition, the calibration apparatus and method according to an embodiment of the present invention can be applied to a projector for spatial augmented reality (SAR) for projecting an image to the real world. For example, as described above, an inverse transformation of the calibration matrix derived by performing camera calibration using the reference object 1000 and the calibration unit 2000 is applied to the image to be projected, and the image is applied to the reference object through the projector. Projector calibration may be performed by projecting on 1000.

As described above, the calibration apparatus and method according to the embodiments of the present invention can be easily manufactured by coupling the light emitting member to the vertex of the rectangular parallelepiped body.

In addition, the calibration apparatus and method according to an embodiment of the present invention can minimize the influence of the lighting environment by providing a light emitting member to each vertex of the body to facilitate the recognition of the vertex.

In addition, in the calibration apparatus and method according to an embodiment of the present invention, a reference object is provided in a rectangular parallelepiped shape so that up to three squares having different angles from the camera can be captured on a single image. Low calibration can be performed.

100: calibration device 200: camera
1000: reference object 1100: body
1200: light emitting member 2000: calibration unit
2100: light emitting member detection unit 2110: filtering unit
2120: light emitting member center detecting unit 2200: square forming unit
2210: polygon forming unit 2220: number of light emitting members
2230: internal segment extraction unit 2300: matrix calculation unit
3000: Reference object control unit S10: Light emitting member position detection step
S20: Rectangle Formation Step S21: Polygon Formation Step
S22: determining number of light emitting members S23: extracting internal line segment
S30: matrix calculation step

Claims (17)

In the device for performing the calibration of the camera,
A reference object having a rectangular parallelepiped body, the reference object including a light emitting member provided at each vertex of the body and generating light;
A camera includes a calibration unit for performing a calibration of the camera using the image of the reference object,
The calibration unit,
A light emitting member position detector for detecting a position of the light emitting member on the image;
And a quadrangle forming unit configured to form a quadrangle by connecting the light emitting members whose positions are detected by the light emitting member position detector on the image,
The quadrangle forming unit includes a polygon forming unit for forming a polygon by connecting the outer light emitting members positioned in the outermost part of each light emitting member on the image where the position is detected by the light emitting member position detecting unit to each other. delete The method of claim 1,
The light emitting member is a calibration device provided by a diffused light emitting diode (Diffused LED). The method of claim 1,
The calibration unit,
And a matrix calculator for obtaining a calibration matrix for each rectangle formed in the rectangle forming unit by using a rectangle-based calibration technique. The method of claim 1,
The light emitting member position detector,
A filtering unit to filter noise on the image;
And a light emitting member center extracting unit configured to derive a position of a center of the light emitting member on the image on which the filtering is performed. The method of claim 5,
The filtering unit filters the noise on the image by using a Gaussian smoothing filtering technique.
And the light emitting member center extracting unit derives the position of the center of the light emitting member on the image filtered by the filtering unit using a binarization technique. delete The method of claim 1,
The polygonal forming unit connects the outer light emitting members sequentially, but forms a closed curve by forming the closed curve by connecting the outer light emitting member which is the starting point of the outer light emitting member to an end point, and whether the closed curve is a convex. Performing a convexity determination to determine the closed curve formation and the convexity determination by changing a connection order of an outer light emitting member of the outer light emitting member, and determining a closed curve determined as a convex among the closed curves as the polygon. Calibration device. The method of claim 1,
The square forming unit,
A light emitting member number determining unit configured to determine the number of the light emitting members on the image;
And an internal line segment extracting unit extracting a line segment sharing a vanishing point with two or more sides of the light side as an internal segment among line segments connecting two light emitting members of the light emitting member in addition to the sides of the polygon. The method of claim 9,
The internal line segment extracting unit does not perform the extraction of the internal line segment when the number of light emitting members on the image is four, and when the number of light emitting members on the image is six and the vanishing point is three, two of the light emitting members are used. Of the light emitting members in the polygon and the outer light emitting members when the number of light emitting members on the image is 7 A calibration device for extracting a line segment sharing a vanishing point with two or more of the sides of the line segments connecting one as the internal line segment. The method of claim 10,
The internal line extracting unit, when the number of light emitting members on the image is six and the number of vanishing points is two, the calibration device for extracting the line segment connecting the two light emitting members intersecting each other the sides sharing the vanishing point as the internal line segment . Calibration device,
Imaging a reference object including a light emitting member for generating light at each vertex of a rectangular parallelepiped shape with a camera; And
Performing calibration of the camera using the image of the reference object picked up by the camera;
The performing of the calibration may include:
A light emitting member position detecting step of detecting a position of the light emitting member on the image;
And forming a rectangle by connecting the light emitting members on the image to each other.
The square forming step,
And a polygon forming step of forming polygons by connecting the outer light emitting members positioned at the outermost sides of the light emitting members on the image where the position is detected by the light emitting member position detection unit with each other. The method of claim 12,
The light emitting member is a calibration method provided by a diffused light emitting diode (Diffused LED). The method of claim 12,
And a matrix calculation step of obtaining a calibration matrix for each rectangle formed in the rectangle forming step by using the rectangle-based calibration technique after the rectangle forming step. The method of claim 12,
In the step of detecting the light emitting member, the noise on the image is filtered using a Gaussian smoothing filtering technique, and a calibration method for deriving the position of the central portion of the light emitting member on the filtered image using a thresholding technique. The method of claim 12,
In the polygon forming step, the outer light emitting members are sequentially connected to each other, but a closed curve is formed to form a closed curve by connecting the outer light emitting member which is a starting point among the outer light emitting members to an end point, and whether the closed curve is a convex. Performing a convexity determination to determine the closed curve formation and the convexity determination by changing a connection order of an outer light emitting member of the outer light emitting member, and determining a closed curve determined as a convex among the closed curves as the polygon. Calibration method. The method of claim 16,
The square forming step,
Determining the number of light emitting members on the image;
After the step of determining the number of light emitting members and forming the polygon, the line segment sharing the vanishing point with at least two sides of the light emitting member among the line segments connecting two light emitting members of the light emitting member in addition to the sides of the polygon is extracted as an internal line segment. Further comprises an internal segment extraction step,
In the internal line segment extraction step, if the number of light emitting members on the image is four, the extraction of the internal line segment is not performed. When the number of light emitting members on the image is six and the number of vanishing points is two, the respective vanishing points are shared. A line segment connecting two light emitting members whose sides cross each other is extracted as the internal line segment. When the number of light emitting members on the image is six and the vanishing point is three, the two light emitting members of the light emitting member are connected in addition to the side. Line segments that share a vanishing point with two or more of the sides among the line segments as the inner line segments, and when the number of light emitting members on the image is seven, line segments connecting one of the light emitting member in the polygon and the outer light emitting member A line segment sharing a vanishing point with two or more of the sides as the internal segment Calibration method to extract.

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