JP2006013854A - Camera controller, and camera control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To move a camera visual field so as to position a designated part at the center of an image screen with the same and high precision even when the arbitrary part of the image screen to be picked-up is designated without having an effect on the view angle of a camera. <P>SOLUTION: An absolute coordinate with the place of an imaging apparatus as an original point is granted to spaces surrounding a camera controller through the use of three-dimensional coordinate axes. A first length is calculated based on relation of trigonometric function between the view angle of the camera and the resolution of the image screen, so as to give it to one of absolute coordinate axes as a unit. The image screen exists as a plane which contacts a sphere with the original point as a center and with the first length as a radius. The center of the image screen is a contact point between the sphere and the plane. The whole spaces are expressed by the three-dimensional absolute coordinate, and the locuses of panning and tilting on the surface of the sphere are made to be clear. Consequently, the command values of a panning angle and a tilt angle without relying on the view angle of the camera are acquired with high precision. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes an imaging device provided on a pan axis and a tilt axis, and when an arbitrary location on a video screen of the imaging device is specified, the specified location is positioned at the center of the video screen. The present invention relates to a camera control device to be controlled and a camera control method.

  Conventionally, a camera control device designates a specific location (specific location) by clicking on a video screen captured by an imaging device with a mouse or the like so that the specific location is at the center of the video screen. Some can move the camera view.

  In such a camera control device that can freely move the camera field of view, panning is performed based on the coordinates of the video screen corresponding to the viewing angle of the camera and the coordinate information (position information) clicked on the video screen. The angle and tilt angle are calculated, and the imaging device is moved based on the calculated pan angle and tilt angle.

Note that there is a camera control technique described in, for example, (Patent Document 1).
JP 2002-241833 A

  However, in the above-described conventional camera control device, the camera field of view is actually moved to a specific point designated on the video screen as the camera field of view approaches two poles that can be approximated as panning points. After that, an error (camera field-of-view designation error) from the center of the new video screen imaged by the imaging device appears remarkably.

  For this reason, it is necessary to move the camera view using another method (technique) for a portion where a camera view designation error appears remarkably.

  However, in the above-described conventional camera control device, the accuracy of the camera field designation error varies depending on the tilt angle, and the camera field designation error appears remarkably (a point where the pan operation can be approximated as a point is 2). With regard to the poles present at the places, it is extremely difficult to suppress the camera field designation error to 0 even when other methods are used.

  Further, since the camera viewing angle designation error becomes more noticeable as the camera viewing angle becomes wider, it is necessary to provide the imaging apparatus with a restriction that the camera viewing angle is not wide.

  Therefore, in recent years, no matter what part is designated on the video screen captured by the imaging device, the camera is positioned so that the designated part is located at the center of the video screen with the same accuracy and high accuracy. The field of view can be moved, and even if the camera's viewing angle is very wide, the camera field of view can be moved so that the specified location is at the center of the video screen with the same accuracy and high accuracy. There is a demand for a proposal or realization of a camera control device that can be used.

  Therefore, the present invention is not affected by the viewing angle of the camera, and even if an arbitrary part of the captured video screen is specified, the specified part is imaged with the same accuracy and high accuracy. It is an object of the present invention to provide a camera control device and a camera control method capable of moving the camera visual field so as to be positioned at the center of the screen.

  In order to solve this problem, the camera control device of the present invention includes an imaging device provided on the pan axis and the tilt axis, and is designated when an arbitrary portion of a video screen of the imaging device is designated. A camera control device that controls a position to be positioned at the center of a video screen, wherein a sphere centered on the imaging device is provided in a space surrounding the imaging device, and the video screen is a plane in contact with the sphere. Space setting means provided in the space, and absolute coordinate giving means for giving absolute coordinates to the space using a three-dimensional coordinate axis based on a trigonometric function relationship between the viewing angle of the imaging device and the resolution of the video screen Based on the absolute coordinate information given by the absolute coordinate giving means, the pan angle and tilt angle of the imaging device are calculated so that the designated location is located at the center of the video screen. Means out, in which a structure having a camera view moving means to perform the operation and the tilting operation of the pan with respect to the imaging device based on the pan angle and the tilt angle calculated by said calculating means.

  In order to solve this problem, the camera control method of the present invention is configured such that when an arbitrary portion of a video screen of an imaging device provided on the pan axis and the tilt axis is specified, the specified location is the video screen. A camera control method for controlling to be located at the center of the image, wherein a first step of providing a sphere centered on the imaging device in a space surrounding the imaging device, and the video screen as a plane in contact with the sphere, A third step of providing absolute coordinates to the space using a three-dimensional coordinate axis based on a second step provided in the space and a trigonometric relationship between the viewing angle of the imaging device and the resolution of the video screen; And a fourth step of calculating a pan angle and a tilt angle of the imaging device so that the designated location is positioned at the center of the video screen based on the absolute coordinate information given in the step and the third step. And-up, in which a structure comprising a fifth step of causing the operation and the tilting operation of the pan relative to the fourth image pickup device based on the pan angle and the tilt angle calculated by the step of.

  According to the present invention, a sphere centered on the imaging device is provided in a space surrounding the imaging device, and a video screen is provided in the space as a plane in contact with the sphere, and the viewing angle of the imaging device and the video screen are relative to the space. Based on the relation of trigonometric function to the resolution of the image, absolute coordinates are given using a three-dimensional coordinate axis. Further, based on the absolute coordinate information, an image is picked up so that a designated location is positioned at the center of the video screen. By calculating the pan angle and tilt angle of the device, it is not affected by the viewing angle of the camera, and even if any part of the captured video screen is specified, the same accuracy and high An effective effect is obtained in that the camera field of view can be moved with accuracy so that the designated location is located at the center of the video screen.

The invention according to claim 1 of the present invention includes an imaging device provided on the pan axis and the tilt axis, and when an arbitrary location on the video screen of the imaging device is specified, the specified location is the video screen. A camera control device that controls to be positioned at the center, wherein a sphere centered on the imaging device is provided in a space surrounding the imaging device, and a space setting unit that provides the video screen in the space as a plane in contact with the sphere, and the imaging device Based on the trigonometric relationship between the viewing angle of the image and the resolution of the video screen, absolute coordinate giving means for giving absolute coordinates to the space using a three-dimensional coordinate axis, and absolute coordinate information given by the absolute coordinate giving means And calculating means for calculating the pan angle and tilt angle of the imaging device so that the designated location is located at the center of the video screen, and based on the pan angle and tilt angle calculated by the calculation means. And a camera visual field moving means for performing a panning operation and a tilting operation on the imaging device, and a sphere centering on the imaging device is provided in a space surrounding the imaging device, and a video screen is in contact with the sphere Provided in the space as a plane, and gives absolute coordinates to the space using a three-dimensional coordinate axis based on the trigonometric relationship between the viewing angle of the imaging device and the resolution of the video screen. Based on the above, the panning and tilting angles of the imaging device are calculated so that the specified location on the video screen is positioned at the center of the video screen, so that the image is not affected by the viewing angle of the camera. The camera field of view so that the specified location is located at the center of the image screen with the same accuracy and high accuracy even when an arbitrary location is specified on the selected image screen. An effect that can be moved.

  According to the second aspect of the present invention, when an arbitrary portion of the video screen of the imaging device provided on the pan axis and the tilt axis is specified, the specified location is positioned at the center of the video screen. A first step of providing a sphere centered on the imaging device in a space surrounding the imaging device, a second step of providing a video screen in the space as a plane in contact with the sphere, and the imaging device A third step of giving absolute coordinates to the space using a three-dimensional coordinate axis based on the relation of the trigonometric function between the viewing angle of the image and the resolution of the video screen, and the absolute coordinate information given by the third step Based on the fourth step of calculating the pan angle and tilt angle of the imaging device so that the designated location is positioned at the center of the video screen, and based on the pan angle and tilt angle calculated in the fourth step Shoot A camera control method including a fifth step of performing a panning operation and a tilting operation with respect to the device, wherein a sphere centering on the imaging device is provided in a space surrounding the image device, and the video screen is a plane in contact with the sphere Provided in the space, absolute coordinates are given to the space using a three-dimensional coordinate axis based on the trigonometric relationship between the viewing angle of the imaging device and the resolution of the video screen. In addition, the pan angle and tilt angle of the imaging device are calculated so that the designated location on the video screen is positioned at the center of the video screen, so that the captured video is not affected by the viewing angle of the camera. Even if an arbitrary location is specified on the screen, the camera field of view is moved so that the specified location is at the center of the video screen with the same accuracy and high accuracy. It has the effect that the door can be.

  Hereinafter, the best mode for carrying out the present invention will be described more specifically with reference to the drawings. Here, in the accompanying drawings, the same reference numerals are given to the same members, and duplicate descriptions are omitted. In addition, since description here is the best form by which this invention is implemented, this invention is not limited to the said form.

(Embodiment 1)
1 is a perspective view showing the camera control device, FIG. 2 is a block diagram showing the configuration of the camera control device, FIG. 3 is a diagram showing the relationship between the video screen and the imaging device, and FIG. 4 is the state shown in FIG. FIG. 5 is a diagram showing the y-coordinate, FIG. 5 is a diagram showing a video screen viewed from Direction A perpendicular to the straight line O _p O _s in FIG. 4, and FIG. 6 is for determining the length of r ₂ shown in FIG. figure 7 is a diagram for converting the image screen (linear O _p O _s on) point to point P is clicked when the second quadrant is clicked in P '(first quadrant above), FIG. 8 is a diagram in which the state shown in FIG. 7 is captured by yz coordinates, and FIG. 9 is a predetermined pan (Pan) angle and a predetermined tilt (Tilt) for the clicked point P ′ to be the center of the video screen. FIG. 10 is a diagram showing the relationship of angles, FIG. 10 is a diagram showing the state shown in FIG. 9 in the xy coordinate system, and FIG. 11 is shown in FIG. Diagram showing the state in x-z coordinate system, FIG. 12 shows a state in which removed triangle OP'Q 9, 13 is a view from DirectionB 8 image screen (linear O _p O Figure for converting point P which is clicked when the fourth quadrant is clicked in _s on) to the point P '(first quadrant above), 14 x-y coordinate, the state shown in FIG. 9 FIG. 15 is a diagram showing the state shown in FIG. 9 in the xz coordinate system, FIG. 16 is a diagram showing a state in which the triangle OP′Q is taken out in FIG. 9, and FIG. O _p O _s ) and the relationship between the imaging device and the xy coordinate system, FIG. 18 shows the state shown in FIG. 17 in the yz coordinate, and FIG. 19 shows the clicked point P. FIG. 20 is a diagram showing the relationship between a predetermined pan angle and a predetermined tilt angle to be the center of the video screen, and FIG. Diagram showing a state in x-y coordinate system, the triangle OPQ 19 Figure 22 shows a representation 21 of the state shown in FIG. 19 in order to obtain the command value theta _pan pan angle x-z coordinate system FIG.
These are flowcharts which show the process sequence of the calculation process of pan angle and tilt angle by CPU21.

  In the camera control apparatus shown in FIG. 1, a pan axis turning shaft 12 is fixed on a pedestal 11, and the pan axis turning shaft 12 is fixed to an output shaft of a pan axis motor 13. The pan shaft motor 13 is fixed to the control unit 14.

  A tilt axis motor 15 is disposed on the upper end of the control unit 14, and a tilt axis turning shaft 16 is fixed to the output axis of the tilt axis motor 15. Further, an adhesion portion 17 for adhering the tilt axis rotation axis 16 and the imaging device 19 is fixed to the tilt axis rotation axis 16. An imaging device 19 is fixed to the upper part of the bonding portion 17.

  In such a camera control device, when the output shaft of the pan axis motor 13 rotates, the imaging device 19 performs a pan operation (rotates in the horizontal direction, that is, the left and right direction) as in the pan axis operation 18, and the tilt axis. As the output shaft of the motor 15 rotates, the imaging device 19 performs a tilt operation (rotates in the vertical direction, that is, the vertical direction) like the tilt axis operation 20.

  Further, the control unit 14 is provided with a CPU (Central Processing Unit) 21, and as shown in FIG. 2, the CPU 21 is coordinate information of a location indicated on the video screen imaged by the imaging device 19. The pan angle and the tilt angle are corrected based on the above, and a signal Sig1 indicating the corrected pan angle is applied to the pan axis motor 13 and Sig2 indicating the corrected tilt angle is applied to the tilt axis motor 15.

  Inside the CPU 21, coordinates based on the imaging device 19 are set for the space around the imaging device 19 based on a preset resolution of the video screen and a preset viewing angle of the imaging device 19. Then, the coordinate information on the video screen at the location designated on the video screen imaged by the imaging device 19 is converted into the coordinate system set for the space.

  As a result, the CPU 21 can clarify the positional relationship between the imaging device 19 and the designated location, and can also clarify the positional relationship between the imaging device 19 and the video screen captured by the imaging device 19.

  After that, the CPU 21 calculates a pan angle and a tilt angle so that the designated location in the video screen is at the center of the video screen, and the pan angle motor 13 This is applied to the tilt axis motor 15.

  Note that the CPU 21 executes the program corresponding to the processing procedure of the pan angle and tilt angle calculation processing described later, thereby performing the functions of the space setting means, the absolute coordinate giving means, the calculating means, and the camera visual field moving means described above. To fulfill.

  A program corresponding to the processing procedure of the pan angle and tilt angle calculation processing by the CPU 21 and data necessary for the pan angle and tilt angle calculation processing are not shown in a storage device (recording medium such as a hard disk, ROM, RAM, etc.). If necessary, it is read from the storage device into a main storage device (RAM) (not shown) and executed.

In the camera control device of the present invention, (1) absolute coordinates with the origin of the location of the imaging device are given to the space surrounding the camera control device using a three-dimensional coordinate axis, and (2) the camera viewing angle and The first length is calculated from the relation of the trigonometric function with the resolution of the video screen, and this is given as a unit to one of the absolute coordinate axes. (3) At this time, the video screen is centered on the origin and the first It is assumed that there is a plane in contact with a sphere having a radius as a length, and that the center of the video screen is a contact point between the sphere and the plane. As a result, the entire space can be expressed in three-dimensional absolute coordinates, and the pan angle on the surface of the sphere is high and accurate, and the pan angle does not depend on the viewing angle of the camera. The command value for the tilt angle is obtained.

  Next, pan angle and tilt angle calculation processing by the CPU 21 of the camera control apparatus that performs such processing will be described in detail with reference to FIGS.

  Here, the meanings of symbols used in the following description and FIGS. 3 to 22 will be described.

r ₁ represents the length of the contact O _s and the point O _p , r ₂ represents the radius of the sphere, θ _t represents the current tilt angle (elevation angle) [°] of the imaging device 19, and O represents means a position of the imaging device 19, P denotes a point specified in the video screen, p _x is 'means coordinates, p _y is y of the point P' x of the point P means coordinates, O _s is It means the center point of the video screen, Tθ means the viewing angle of the imaging device 19 in the tilt direction ÷ 2 [°], Pθ means the viewing angle of the imaging device 19 in the pan direction ÷ 2 [°], and X _pixel means the number of pixels (resolution) from the origin in the _x′- axis direction to the end of the video screen on the video screen, and Y _pixel means the number of pixels (resolution) from the origin in the y′-axis direction to the end of the video screen on the video screen. ).

Figure 5 shows the state of the video screen viewed relative linear O _p O _s from DirectionA in the vertical direction in FIG. 4. In FIG. 5, since the x′-y ′ coordinate system used in the video screen is determined based on the y ′ axis, it is necessary to correct the coordinates of the x ′ axis in accordance with the y ′ axis. Accordingly, the x ′ coordinate is corrected by calculating the mathematical formula (Equation 1) for the coordinates of the point P.

  In this embodiment, the x′-y ′ coordinate system is determined based on the y ′ axis. However, the present invention is not limited to this, and the x′-y ′ coordinate system is x. It is also possible to make corrections in accordance with the x ′ axis with respect to the coordinates of the y ′ axis determined based on the “axis”.

The relationship between the contact O _s and the point O lengths of the _p r1 and radius r2 of the sphere is expressed by the equation (Equation 2).

  Next, the length of the radius r2 of the sphere is expressed by the equation (Equation 3) as can be seen with reference to FIG. 6 which is a partially enlarged view of FIG.

  From the above formulas (Equation 2) and (Equation 3), the length r1 (see FIG. 4) can be expressed by the equation (Equation 4).

Next, in the case of θ _t <0, in the case of θ _t ≧ 0 and Py> r1, in the case of θ _t ≧ 0 and Py> − (length of line segment OsT), θ _t ≧ 0 and − (line segment O The calculation of the pan angle and the tilt angle in the case of _s T length) ≦ Py ≦ r1 will be described.

First, a case where case A (case A) = θ _t <0 will be described.

  Here, FIG. 4 shows a state in which FIG. 3 representing the relationship between the video screen 33 and the imaging device 19 is represented by xy coordinates. FIG. 4 is also a view seen from Direction B in FIG.

  In the xy coordinate system shown in FIG. 4, in order to convert the clicked point P into the first phenomenon and handle it, the transformation shown in the mathematical expressions shown in (Equation 5) and (Equation 6) is performed.

After performing such conversion, it is determined which pattern of case B (Case B), case C (Case C), and case D (Case C), which will be described later, and described in the corresponding pattern. A predetermined process is performed to calculate θ _pan and θ _tilt which are _pan angle and tilt angle. For θ _tilt , the mathematical expression of (Equation 7) is calculated (converted) with respect to θ _tilt obtained in the above procedure to obtain a final command value.

(1) Case B pattern (when θ _t ≧ 0 and Py> r1)
Here, the diagram to convert the video screen (linear O _p O _s on) point of the second quadrant point is clicked when clicked P in P '(first quadrant top) in FIG. 7 Show. FIG. 7 is also a view seen from Direction B in FIG. FIG. 8 is a diagram in which the state shown in FIG. 7 is captured by yz coordinates, and shows that the x ′ coordinates in FIG. 5 are equivalent to the z coordinates.

  In FIG. 7, in order to convert the clicked point P into a point P ′, it is necessary to convert Py into Pya and Px into Pxa.

Py corresponds to the y ′ coordinate of the point P converted on the video screen (on the straight line O _p O _s ), that is, the length of the line segment O _s P in the xy coordinate system shown in FIG. Further, Pya corresponds to the length of the video screen (linear O _p O _s on) points are translated at the coordinates' y of 'P, i.e. the line segment O _s P in x-y coordinate system shown in FIG. 7' .

  A conversion formula for converting Py to Pya based on the contents of FIG. 7 will be described. First, the mathematical formula (Equation 8) is established from the contents of FIG.

Here, the relationship between Py and α (∠POO _p , ∠O _p OP ′) is expressed by the equation (Equation 9).

  Therefore, Pya can be expressed by the equation (Equation 10) from the equation (8) and the equation (9).

  Next, FIG. 9 shows a relationship between a predetermined pan angle and a predetermined tilt angle so that the clicked point P ′ becomes the center of the video screen. FIG. 11 shows a state in which the state shown in FIG. 9 is expressed in the xy coordinate system.

  A conversion formula for converting Px to Pxa based on the content of FIG. 11 will be described. First, from the contents of FIG. 11, the relational expressions represented by the mathematical expressions of (Equation 11), (Equation 12), and (Equation 13) are established.

  (Formula of ∵ (Equation 4))

(Formula of ∵ (Equation 3))
Here, since Zp ′ is Zp ′ = (Zp / Xp) · Xp ′ from the content of FIG. 11, Zp ′ is calculated from the equations of (Equation 11), (Equation 12), and (Equation 13). (Expression 14)

  Here, since Pxa = Zp ′, Pxa can be expressed by an equation of (Expression 15).

As described above, the command value θ _pan of the _pan angle is expressed by the equation (Equation 16) when Px ≧ 0, and is expressed by the equation (Equation 17) when Px <0. The

Next, a tilt angle command value θ _tilt is obtained. From FIG. 10 in which the contents shown in FIGS. 9 and 9 are expressed in the xy coordinate system, the length of the line segment OQ is expressed by the equation (Equation 18).

  From the equation (Equation 18), the length of the line segment OP ′ can be expressed by the equation (Equation 19).

  Here, the relational expression shown by the mathematical expression (Equation 20) is established from the contents of FIG. 12 showing the state in which the triangle OP′Q is extracted in FIG. 9.

  Further, from the content of FIG. 10 in which the state of FIG. 9 is expressed in the xz coordinate system, the relationship represented by the mathematical expression of (Expression 21) is established.

From the above, the tilt angle command value θ _tilt can be obtained by calculating ( _Equation 22).

(Formula of ∵ (Equation 10), Equation (Equation 15))
(2) CaseC pattern (in the case of θ _t ≧ 0 and Py <− (length of line segment OsT))
Here, the diagram to convert the video screen (linear O _p O _s on) in the fourth quadrant point a point P which is clicked when is clicked P '(first quadrant top) in FIG. 13 Show. FIG. 13 is also a view seen from Direction B in FIG.

  In FIG. 13, in order to convert the clicked point P into a point P ′, it is necessary to convert Py into Pya and Px into Pxa.

Py corresponds to the y ′ coordinate of the point P converted on the video screen (on the straight line O _p O _s ), that is, the length of the line segment O _s P in the xy coordinate system of FIG. Further, Pya corresponds to the y ′ coordinate of the point P ′ converted on the video screen (on the straight line O _p O _s ), that is, the length of the line segment O _s P ′ in the xy coordinate system of FIG.

  A conversion formula for converting Py to Pya will be described based on the contents of FIG. First, based on the contents of FIG. 13, the relational expression expressed by the mathematical expression (Equation 23) is established.

  Here, the relationship between Py and β (∠POT, ∠TOP ') is expressed by the equation (Equation 24).

  Therefore, Pya can be expressed by the equation (Equation 25) from the equations (Equation 23) and (Equation 24) described above.

A conversion formula for converting Px to Pxa will be described based on the contents of FIG. 15 in which the state shown in FIG. 9 is expressed in the xz coordinate system. From the content of FIG. 15, three relational expressions represented by the mathematical expressions of (Equation 26), (Equation 27), and (Equation 28) hold.

  Here, since Zp ′ is Zp ′ = (Zp / Xp) · Xp ′ from the content of FIG. 15, Zp ′ is obtained from the equations of (Equation 26), (Equation 27), and (Equation 28). Can be expressed by the equation (Equation 29).

  Here, since Pxa = Zp ′, Pxa can be expressed by an equation of (Equation 30).

From the above, the command value θ _pan of the _pan angle is expressed by the equation (Equation 31).

Next, a tilt angle command value θ _tilt is obtained. From FIG. 14 in which the contents shown in FIG. 9 and FIG. 9 are expressed in the xy coordinate system, the length of the line segment OQ is expressed by an equation (Equation 32).

  Further, the length of the line segment OP ′ can be expressed by the equation (Equation 33) from the equation (Equation 32).

  Here, from FIG. 16 showing a state where the triangle OP'Q is extracted in FIG.

  Further, from the contents of FIG. 14, the relational expression represented by the mathematical expression (Equation 35) is established.

From the above, the tilt angle command value θ _tilt can be obtained by calculating the mathematical formula (Equation 36).

(Formula of ∵ (Equation 25), Equation (Equation 30))
Finally, since the originally designated portion is the fourth _quadrant , it is necessary to convert the above-mentioned θ _tilt as follows.

(3) CaseD pattern (when θ _t ≧ 0 and − (length of line segment OsT) ≦ Py ≦ r1)
In order to obtain the _pan angle command value θ _pan , the pan angle θ _pan can be expressed by the equation (Equation 38) from FIG. 21 which shows the state shown in FIG. 19 in the xz coordinate system. .

Here, since the values of Xp and Zp are respectively Xp = r 2 · cos θ _t −Py · sin θ _t and Zp = Px, the command value θ _pan of the _pan angle is expressed by the equation (Equation 39). It can be obtained by calculation.

Next, a tilt angle command value θ _tilt is obtained. Here, FIG. 19 and FIG. 20 showing the state shown in FIG. 19 in the xy coordinate system, the length of the line segment OQ can be expressed by the mathematical formula (Equation 40).

  Further, from the equation (Equation 40), the length of the line segment OP can be expressed by the equation (Equation 41).

  Here, from FIG. 22 showing a state in which the triangle OPQ is extracted in FIG. 19, the relationship represented by the mathematical expression of (Expression 42) is established.

  Further, from the contents shown in FIG. 20, the relational expression represented by the mathematical expression (Equation 43) is established.

From the above, the tilt angle θ _tilt can be obtained by calculating the mathematical formula (Equation 44).

(Formula of ∵ (Equation 43))
Incidentally, showing the state in which the relationship between video screen and (on the straight line O _p O _s) and the imaging device represented by x-y coordinate system in Figure 17. FIG. 17 is also a view seen from Direction B in FIG. FIG. 18 is a diagram in which the state shown in FIG. 17 is captured by yz coordinates, and shows that the x ′ coordinates shown in FIG. 5 are equivalent to the z coordinates.

  As described above, the CPU 21 has the coordinate information of the location indicated on the video screen imaged by the imaging device 19, the current tilt angle when the command is given, the viewing angle in the tilt direction of the imaging device 19, and the imaging device. Accurate pan and tilt angles can be designated from the four pieces of information on the viewing angle in the 19 pan directions so that the indicated location is the center of the video screen.

  Next, the pan angle and tilt angle calculation processing by the CPU 21 will be described with reference to FIG. FIG. 23 is a flowchart showing a processing procedure for calculating the pan angle and the tilt angle by the CPU 21. Specifically, the point indicated on the video screen captured by the imaging device 19 is positioned at the center of the video screen. The processing procedure for processing is shown in FIG.

  When the CPU 21 receives an instruction for an arbitrary position on the video screen, the CPU 21 corrects the coordinates on the video screen (step ST1), and initializes the variable case_a by substituting 0 into the variable case_a ( Step ST2) After that, based on the coordinate information corrected by executing step ST1 and the above four pieces of information, which pattern is classified into four patterns of case A, case B, case C, and case D to be described later? Make a decision. As the first step, it is determined whether it is case A (step ST3).

  The CPU 21 that has determined that it is case A in step ST3 corrects the parameter (step ST4), and then assigns 1 to the variable case_a (step ST5), and further changes any of the four patterns of caseB, caseC, and caseD. It is discriminated whether it is classified (step ST6).

  If it is determined in step ST6 that it is case B, the pan and tilt angles for case B are calculated to calculate the desired pan and tilt angles (step ST7).

  If it is determined in step ST6 that it is case C, the pan and tilt angles for case C are calculated to calculate desired pan and tilt angles (step ST8).

  Further, when it is determined in step ST6 that it is case D, the pan and tilt angles for case D are calculated to calculate the desired pan and tilt angles (step ST9).

  CPU21 which complete | finished any step of step ST7-9 determines whether the value of variable case_a is 1 (step ST10), and when it is judged that the value is 1 as a result of this judgment Then, the tilt angle calculated by executing any one of the above steps ST7 to ST9 is corrected (step ST11), and then the pan angle calculated by executing any one of the above steps ST7 to 9 is used as the pan axis motor. 13 and the tilt angle corrected by executing step ST11 is given to the tilt axis motor 15 (step ST12).

  By the way, the CPU 21 that has determined that the value of the variable case_a is not 1 in step ST10 uses the pan angle motor 13 and the tilt axis motor respectively for the pan angle and tilt angle values calculated by executing any one of the steps ST7 to ST9. 15 (step ST12).

  When step ST12 is completed, the specific location indicated on the video screen comes to be located at the center of the video screen after the end of the panning and tilting operations.

  As described above, according to the camera control apparatus of the present embodiment, coordinates are set for the space around the imaging device 19, and the triangle between the resolution of the video screen of the imaging device 19 and the viewing angle of the imaging device 19 is set. The value of the coordinates is set based on the relationship of the functions, and the video screen is processed as if it is a plane that touches the sphere centered on the imaging device 19 and the setting is at the center of the screen. The position of the specified position in the center of the video screen is not affected by the viewing angle of the imaging device 19 or the current tilt angle. The pan angle and tilt angle can be specified so as to be in the center of.

  This is because, according to the camera control apparatus of the present embodiment, exactly the same accuracy (positioning accuracy) can be obtained even in the vicinity of two extreme points where the pan operation can be approximated as a point, and the viewing angle of the camera Means that the same accuracy (alignment accuracy) can be obtained even when the viewing angle is a wide angle close to 180 degrees.

  When a specific place is monitored using a camera device for the purpose of improving security, the camera field of view has been used in a fixed state or a semi-fixed state that can be moved only to a predetermined place. However, when a user's needs increase and a system that can specify the field of view freely is constructed, when an arbitrary part of the video screen captured by the imaging device of the camera device is specified, the specified part is displayed on the video screen. It is required to move the camera field of view so that it becomes the center of the image.

In this case, the error between the location designated on the video screen and the location where the camera field of view has actually moved to become the new center of the video screen is theoretically suppressed to 0 or the error is minimized (as long as possible) When the system is intended to prevent the error from varying according to the designated location even when the viewing angle of the imaging device is very wide, The camera control device and the camera control method of the present invention can be applied.

  Also, for example, in the case of moving the camera field of view following a specific person in a real-time system, the function is realized by applying the camera control method of the present invention at predetermined intervals using an internal interrupt or the like. It becomes possible.

A perspective view showing a camera control device Block diagram showing the configuration of the camera control device Diagram showing the relationship between video screens and imaging devices The figure which represented the state shown in FIG. 3 by xy coordinate FIG. 4 is a diagram showing a video screen viewed from Direction A in a direction perpendicular to the straight line O _p O _{s in} FIG. Diagram for determining the length of r ₂ shown in FIG. Figure for converting the video screen (linear O _p O _s on) point of the second quadrant point is clicked when clicked P in P '(first quadrant above) The figure which caught the state shown in FIG. 7 by yz coordinate The figure which shows the relationship between the predetermined | prescribed pan (Pan) angle and predetermined tilt (Tilt) angle for the clicked point P 'to become the center of a video screen. The figure which represented the state shown in FIG. 9 by xy coordinate system The figure which represented the state shown in FIG. 9 by the xz coordinate system FIG. 9 is a diagram showing a state in which the triangle OP′Q is taken out in FIG. Converted to Figure a and image screen viewed from DirectionB 8 (linear O _p O _s on) in the fourth quadrant point a point P which is clicked when is clicked P '(first quadrant above) Illustration for The figure which represented the state shown in FIG. 9 by xy coordinate system The figure which represented the state shown in FIG. 9 by the xz coordinate system FIG. 9 is a diagram showing a state in which the triangle OP′Q is taken out in FIG. The figure which represented the relationship between a video screen (on the straight line O _p O _s ) and an imaging device in an xy coordinate system. The figure which caught the state shown in FIG. 17 by yz coordinate The figure which shows the relationship between the predetermined pan angle and the predetermined tilt angle for the clicked point P to become the center of a video screen The figure which represented the state shown in FIG. 19 by xy coordinate system FIG. 19 is a diagram showing the state shown in FIG. 19 in the xz coordinate system for _{obtaining the pan} angle command value θ _pan . FIG. 19 is a diagram showing a state in which the triangle OPQ is taken out in FIG. The flowchart which shows the processing operation | movement of the calculation process of pan angle and tilt angle by CPU.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Base 12 Pan axis turning axis 13 Pan axis motor 14 Control part 15 Tilt axis motor 16 Tilt axis turning axis 17 Adhesion part 18 Pan axis operation | movement 19 Imaging equipment 20 Tilt axis operation | movement 21 CPU
22 Pan axis motor 23 Tilt axis motor 31 Pan operation 32 Tilt operation 33 Video screen 51 Point specified on video screen with coordinate P (Px, Py)

Claims (2)

Camera control including an imaging device provided on the pan axis and the tilt axis, and controlling so that the designated location is positioned at the center of the video screen when an arbitrary location on the video screen of the imaging device is designated A device,
A space setting means for providing a sphere centered on the imaging device in a space surrounding the imaging device and providing the video screen in the space as a plane in contact with the sphere;
Based on a trigonometric relationship between the viewing angle of the imaging device and the resolution of the video screen, absolute coordinate giving means for giving absolute coordinates to the space using a three-dimensional coordinate axis;
Based on the absolute coordinate information given by the absolute coordinate giving means, calculating means for calculating the pan angle and tilt angle of the imaging device so that the designated location is located at the center of the video screen;
Camera visual field moving means for performing panning and tilting operations on the imaging device based on the pan angle and tilt angle calculated by the calculation unit;
A camera control device comprising: A camera control method for controlling an arbitrary position of a video screen of an imaging device provided on a pan axis and a tilt axis so that the specified position is positioned at the center of the video screen, A first step of providing a sphere centered on the imaging device in a space surrounding the imaging device; a second step of providing the video screen in the space as a plane in contact with the sphere;
A third step of giving absolute coordinates to the space using a three-dimensional coordinate axis based on a trigonometric relationship between the viewing angle of the imaging device and the resolution of the video screen;
A fourth step of calculating a pan angle and a tilt angle of the imaging device so that the designated location is positioned at the center of the video screen based on the absolute coordinate information given in the third step;
A fifth step of performing a pan operation and a tilt operation on the imaging device based on the pan angle and the tilt angle calculated in the fourth step;
A camera control method comprising:

Images