JP2000067273A - Device and method for determining visual field information and recording medium recording program for executing the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily restore the three-dimensional(3D) information of an object by easily acquiring a camera parameter from one 2D image. SOLUTION: Concerning this visual field information determining method, when a rectangular area in a 3D space is displayed as a rectangle in a 2D image, the rectangle in the 2D image is set by a rectangle setting part 100 and the information showing the position of the rectangular area in the 3D space, the length of two sides and the scale of reduction is inputted by a geometrical information input part 200. The information showing the position of the rectangular area, the length of two sides and the scale of reduction is displayed in the 2D image by a geometrical information display part 400. While using the geometrical information inputted by the geometrical information input part 200, a viewpoint calculating part 301 calculates the projection center of an image, namely, viewpoint and a visual field information determining part 302 determines a virtual 3D visual field from the calculated viewpoint position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a method for adding depth information to a two-dimensional image or combining an object generated by three-dimensional computer graphics (CG) into a two-dimensional image. More specifically, the present invention relates to a method for obtaining view parameters for acquiring a camera parameter at the time of capturing an original two-dimensional image and constructing a virtual three-dimensional space.

[0002]

2. Description of the Related Art Conventionally, when a two-dimensional image photographed by a camera or the like and a virtual object generated by three-dimensional CG are synthesized, the two-dimensional image lacks depth information. In order to realize the above, it is necessary to supplement depth information to a two-dimensional image by some means.

As a conventional technique for restoring three-dimensional information from a two-dimensional image, a method of extracting corresponding points of a plurality of images photographed from different viewpoints and restoring three-dimensional information of the points is general. . However, in this method, it is impossible to restore three-dimensional information from one two-dimensional image.

However, the position, shape and exact size of a target object in an image whose three-dimensional information is to be restored are known,
Assuming that the camera that captured the image is an ideal pinhole camera, it is possible to restore the camera parameters of capturing the image and the three-dimensional information of the target object from one image. Here, the camera parameters are parameters of the viewpoint position, the distance from the viewpoint to the target object, the angle of view, and the line of sight.

That is, assuming that a rectangular area displayed on an image is a projection of a rectangle in a three-dimensional space, if the coordinate values of vertices constituting the rectangle are known, the position of the viewpoint (camera) is , Is easily derived from the principle of projective geometry. Such a method of obtaining the position of the viewpoint is described in the following documents 1 and 2.

Reference 1: George A, Jennin
gs, "Modern Geometrywith Ap
applications ", Springer-Verl
ag, 1994. Japanese translation: G. Jennings, Masao Iri, Bijin Irisa, "Introduction to Geometry", Iwanami Shoten 199
6. .

Reference 2: Rogers, Adams, "M
atomic Elements for Co
mputer Graphics ", McGraw-Hi
11, 1990. Japanese translation: Kawai translation, "Computer Graphics Second Edition", Nikkan Kogyo Shimbun, 1993. .

For example, as shown in FIG. 5 (a), when a pair of opposing sides of a rectangular area in an image are parallel, the viewpoint is viewed from the intersection (extinction point) V of the extension of the non-parallel set of sides. a is on a straight line drawn vertically, four points of the original rectangle is projected as a rectangle in the two-dimensional image P _1, P _2, P
_3, by providing the coordinate values of P _4, it is possible to calculate the position of the viewpoint (the distance from the image). This principle is the same even when the rectangular area in the image does not have a set of parallel sides as shown in FIG. At this time, the vanishing point is 2
A point (V ₁ , V ₂ ) exists, and the viewpoint is on a semicircle perpendicular to the image with V ₁ and V ₂ as both ends of the diameter.

[0009] Instead of the coordinate values of the four vertices, the position of one or two vertices and the length of two orthogonal sides of the original rectangle may be given.

However, the coordinate values of the four vertices of these rectangles are not arbitrary values, and must be on a straight line connecting the viewpoint and the vertices of the quadrangle in the image.
There was a problem that input was difficult without actual measurement data.

[0011]

In the above-described conventional view information determining apparatus, in order to construct a virtual three-dimensional space from two-dimensional coordinates, four vertices of a rectangular area are required to calculate a viewpoint position. Coordinate values are required, but there is a problem that it is difficult to input the coordinate values of these four vertices without actual measurement data.

An object of the present invention is to provide a visibility information determining apparatus and method which can easily acquire camera parameters from one two-dimensional image and restore three-dimensional information of a target object.

[0013]

In order to achieve the above-mentioned object, a visual field information determining apparatus according to the present invention provides a visual field information determining apparatus which is capable of displaying a rectangular area in a three-dimensional space as a rectangular area in a two-dimensional image. A view information determining device for constructing the three-dimensional space from a three-dimensional image,
Geometric information input means for inputting geometric information of the position in the dimensional space, the length of the two sides, and the scale, and displaying the information of the position, the length of the side, and the scale of the rectangular area in the two-dimensional image. Geometric information display means, and view information calculating means for calculating camera parameter information of the two-dimensional image taken from the information on the position, length of two sides, and scale of the rectangular area input by the geometric information input means. Have.

[0014] Further, another next-time information determining apparatus of the present invention comprises:
A viewpoint calculation unit configured to calculate a viewpoint that is a projection center of the two-dimensional image using the geometric information input by the geometric information input unit; and a viewpoint position calculated by the viewpoint calculation unit. And visibility information determining means for determining three-dimensional visibility information.

According to the present invention, the viewpoint calculation means calculates the projection center of the image, that is, the viewpoint, using the geometric information input by the geometric information input means, and the view information determining means calculates the virtual viewpoint from the calculated viewpoint position. Since the three-dimensional field of view is determined, it is possible to easily obtain camera parameters from one two-dimensional image and obtain virtual field information.

In another aspect of the present invention, the geometric information input by the geometric information input means includes certain height information given in a normal direction of the rectangular area. .

In another aspect of the present invention, the certain height information is a numerical value indicating a human height.

The present invention is effective when it is desired to arrange a synthesized human image on the rectangular area.

Further, in another view information determining apparatus of the present invention, there is further provided a quadrangular area selecting section for designating the rectangular area from the two-dimensional image.

[0020]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a visibility information determining apparatus according to an embodiment of the present invention.

The visual field information determining apparatus of the present embodiment is based on the premise that a rectangular area in a two-dimensional image is a projection of a rectangular area in a three-dimensional space. And
The three-dimensional space is constructed from the two-dimensional image using the coordinates of an arbitrary quadrangle in the two-dimensional image and the geometric information of the rectangle in the three-dimensional space.

The view information determining apparatus of the present embodiment comprises a quadrangular area selecting section 100, a geometric information input section 200, a view information calculating section 300, and a geometric information display section 400.

The quadrilateral area selection unit 100 selects a target quadrilateral area from the two-dimensional image. The geometric information input unit 200 inputs the position, length of two sides, and scale information of a rectangular area displayed as a quadrangle in a two-dimensional image. The view information calculation unit 300 includes the geometric information input unit 200
Calculates the view information from the information input by. The geometric information display unit 400 uses the calculated view information,
The geometric information is displayed in the two-dimensional image.

Using this embodiment, the geometric information display unit 40
By inputting geometric information using the geometric information input unit 200 while confirming the view information at 0, it is possible to set desirable view information.

FIG. 2 is a block diagram showing in detail the configuration of the visibility information determining device of the present embodiment.

The rectangular area selecting section 100 comprises a rectangular setting section 101 and a vanishing point calculating section 102.

The rectangle setting unit 101 extracts a rectangle in an image. The square may be set in advance,
In that case, the square setting unit 101 can be omitted. Alternatively, a square may be set, for example, by designating four points in the image.

The vanishing point calculation unit 102 finds a vanishing point by finding the intersection of the extension lines of the sides of the rectangle. The coordinate value of the vanishing point may be a relative value, for example, a unit using the number of pixels of an image as a unit.

The geometric information input unit 200 includes a scale setting unit 20
1, a position setting unit 202, and a size setting unit 203.

The scale setting unit 201 determines a scale which is a ratio of a unit length of a two-dimensional image to a length in an actual three-dimensional space. That is, the target two-dimensional image is shown in FIG.
Assuming that a certain region on the screen on a virtual vertical plane as shown in FIG. 5B is displayed, the size ratio between the region and the displayed two-dimensional image is specified. Things.

The position setting unit 202 determines the position of a rectangle in the real world represented by a quadrangular area. The inclination of the plane including the rectangle in the real world with respect to the horizontal plane may be any value, but for simplicity, the following description assumes that the rectangle is on the horizontal plane. The information indicating the position is, for example, the height of a horizontal plane including a rectangle.

The size setting unit 203 determines the size of a rectangle in the real world represented by the rectangle. For example, it is the length of two sides of the rectangle, or the height of a rectangular parallelepiped when the rectangle is virtually given a thickness to form a rectangular parallelepiped.

The scale setting unit 201, the position setting unit 202, and the size setting unit 203 are not all necessary. For example, if the scale of the image and the length of one side of the rectangle are determined, the position of the rectangle is uniquely determined. Therefore, the scale setting unit 201,
Any combination of the position setting unit 202 and the size setting unit 203 may be used, and the combination may be performed in any order.

The view information calculation unit 300 includes the viewpoint calculation unit 30
1 and a view information determination unit 302.

The viewpoint calculation unit 301 includes the geometric information input unit 20
Using the geometric information input by 0, the projection center or viewpoint of the image is calculated.

The view information determining unit 302 determines a virtual three-dimensional view from the calculated viewpoint position. That is, the obtained viewpoint is used as the projection center, and a rectangle whose position and size are determined is projected on a screen on a vertical plane, and when a certain area is enlarged or reduced, the rectangular area set by the square setting unit 101 and A visible range (viewing volume) is set in the computer so as to be the same. Thereby, for example, a virtual object can be generated in the viewing volume.

The geometric information display unit 400 displays rectangular geometric information using the view information using the viewpoint. In the visibility information determination device of the present embodiment, the geometric information display unit 400
The geometric information displayed is checked, and the scale of the image, the position of the rectangle, the size, and the like are appropriately changed by the geometric information input unit 200 as necessary. Note that a numerical value representing the height of a person, such as the average height of a Japanese boy, may be used as the height information of the rectangle. The use of such height information is effective when, for example, a rectangular area is a floor, a road, or the like, and a synthesized human image or the like is to be arranged on the rectangular area.

Next, the processing in the visibility information determining apparatus of this embodiment will be described with reference to the flowchart of FIG.

First, a two-dimensional image is displayed (step 10). Next, the quadrangle setting unit 101 extracts a quadrangle in the image (step 11). The vanishing point is calculated by the vanishing point calculating unit 102 (Step 1).
2).

Then, the scale setting unit 201 specifies the size ratio between the area and the displayed image (step 13). Next, the position setting unit 202 determines the position of the rectangle in the real world represented by the square (step 14). Then, the size setting unit 203 determines the size of the rectangle in the real world represented by the quadrangle based on the length of two sides of the rectangle, the height of the rectangular parallelepiped when the rectangle is virtually thickened to form a rectangular parallelepiped ( Step 15).

Then, the viewpoint calculation unit 301 calculates the projection center of the image, that is, the viewpoint, using the geometric information input by the geometric information input unit 200 (step 16). In the view information determining unit 302, a virtual three-dimensional view is determined from the calculated viewpoint position (step 17).

Finally, the geometric information display unit 400 displays the rectangular geometric information in the two-dimensional image using the view information using the viewpoint (step 18).

Then, the geometric information displayed by the geometric information display unit 400 is confirmed, and if there is no problem, the processing is terminated. If necessary, the scale of the image, the position and size of the rectangle, and the like are input by the geometric information input unit 200. Change as appropriate (step 19).

By repeating the above processing, desired view information can be obtained.

FIG. 4 shows a specific example of setting and displaying geometric information.

FIG. 4A is a diagram showing an example of setting a rectangular area, FIG. 4B is a diagram showing an example of setting and displaying length information, and FIG. FIG. 4D is a diagram illustrating an example of setting and displaying of height information, and FIG. 4D is a diagram illustrating an example of setting and displaying of length and height information.

Although not shown in the figure, the view information determining apparatus of the present embodiment includes a recording medium storing a program for executing the view information determining method.
This recording medium may be a magnetic disk, a semiconductor memory or another recording medium.

This program is read from the recording medium into the view information determining device and controls the operation of the view information determining device. The visibility information determining device executes the above processing under the control of this program.

[0050]

As described above, the present invention has an effect that the viewpoint position can be determined from one image and virtual view information can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a view information determination device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a detailed configuration of the view information determination device of FIG. 1;

FIG. 3 is a flowchart showing an operation of the view information determination device in FIG. 1;

FIG. 4 is a diagram showing an example of setting a rectangular area (FIG. 4)
(A)), a diagram showing an example of setting and displaying length information (FIG. 4B), and a diagram showing an example of setting and displaying other length information (FIG. 4C), and FIG. 5D is a diagram illustrating setting and display examples of length and height information (FIG. 4D).

FIG. 5 is a diagram for explaining the principle of view information determination.

[Explanation of symbols]

 10 to 19 step 100 rectangular area selecting unit 101 rectangular setting unit 102 vanishing point calculating unit 200 geometric information input unit 201 scale setting unit 202 position setting unit 203 size setting unit 300 view information calculating unit 301 viewpoint calculating unit 302 view information determining unit 400 Geometric information display

Claims (15)

[Claims] 1. A view information determining device for constructing a three-dimensional space from a two-dimensional image when a rectangular region in a three-dimensional space is displayed as a quadrangular region in a two-dimensional image, Geometric information input means for inputting the geometric information of the position, the length of the two sides, and the scale in the three-dimensional space, and the information of the position, the length of the side, and the scale of the rectangular area in the two-dimensional image. Geometric information display means to be displayed; and view information calculation for calculating camera parameter information for capturing the two-dimensional image from information on the position, length of two sides, and scale of the rectangular area input by the geometric information input means. View information determining device having means. 2. A view point calculation unit that calculates a viewpoint that is a projection center of the two-dimensional image using geometric information input by the geometric information input unit; The view information determining apparatus according to claim 1, further comprising: view information determining means for determining three-dimensional view information from the determined viewpoint position. 3. The view information determining apparatus according to claim 1, wherein the geometric information input by the geometric information input means includes certain height information given in a normal direction of the rectangular area. . 4. The visibility information determination device according to claim 3, wherein said certain height information is a numerical value indicating a height of a human. 5. The visibility information determination device according to claim 1, further comprising a quadrangular region selecting unit for designating the rectangular region from the two-dimensional image. 6. A view information determining method for constructing the three-dimensional space from the two-dimensional image when a rectangular region in the three-dimensional space is displayed as a square region in the two-dimensional image, Inputting geometric information of the position, length of two sides, and scale of the rectangular area in the three-dimensional space; displaying information of the position, length of sides, and scale of the rectangular area in the two-dimensional image; A view information determination method for calculating camera parameter information of the two-dimensional image taken from the input information of the position, the length of each side, and the scale of the rectangular area. 7. Calculating camera parameter information for capturing the two-dimensional image from information on the input position, length of two sides, and scale of the rectangular area, using the input geometric information. The view information determination method according to claim 6, wherein a view point that is a projection center of the two-dimensional image is calculated, and three-dimensional view information is determined from the calculated view point position. 8. When inputting the position of the rectangular area in a three-dimensional space, the length of two sides, and the geometric information of the scale, certain height information given in the normal direction of the rectangular area is also used. The view information determination method according to claim 6 or 7, which is input. 9. The visibility information determining method according to claim 8, wherein the certain height information is a numerical value indicating a height of a human. 10. The view information determination method according to claim 6, further comprising a process of specifying the rectangular area from the two-dimensional image. 11. When a rectangular area in a three-dimensional space is displayed as a quadrangular area in a two-dimensional image, a view information determining method for constructing the three-dimensional space from the two-dimensional image is performed. A recording medium on which a program is recorded, a process of inputting geometric information of a position, a length of two sides, and a scale of the rectangular area in a three-dimensional space; A process of displaying scale information in the two-dimensional image; a process of calculating camera parameter information of the two-dimensional image taken from the input position of the rectangular area, length of two sides, and scale information. Recording medium on which a program for executing the program is recorded. 12. A process of calculating camera parameter information of the captured two-dimensional image from the input information on the position, length of two sides, and scale of the rectangular area, using the input geometric information. 12. The method according to claim 11, further comprising: calculating a viewpoint that is a projection center of the two-dimensional image, and determining three-dimensional view information from the calculated viewpoint position. A recording medium on which a program is recorded. 13. A fixed height given in a normal direction of the rectangular area in a process of inputting the position of the rectangular area in the three-dimensional space, the length of two sides, and the geometric information of the scale. 13. A recording medium recording a program for executing the visibility information determination method according to claim 11, wherein information is also input. 14. The recording medium according to claim 13, wherein the certain height information is a numerical value indicating the height of a person. 15. A recording medium recording a program for executing the visibility information determination method according to claim 11, further comprising a process of designating the rectangular area from the two-dimensional image.