JP2002204378A - Imaging method and imaging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging method and imaging system capable of grasping a position relations with high precision between a camera and a imaging subject at low cost and also without any constrains in imaging. SOLUTION: In imaging the subject by a camera 4 mounted on a moving base 2 via a pan head, a reference position on a floor where the base 2 is moving and a reference angle of the base 2 are set (STEP1), moving amount of the base from the reference position and a self rotation angle from the reference angle are detected (STEP2), the reference position, the reference angle, the moving amount of the bade 2, the position and the angle of the camera 4 from the rotation angle to the subject are grasped (STEP3), and data of the position and the angle of the camera 4 to the subject is sent to a computer generating video including real-life images of the subject by the camera 4 (STEP4).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting method and a position detecting system for a mobile camera system used for shooting a movie, a television, etc., and more particularly to a mobile camera suitable for shooting in a virtual studio. The present invention relates to a system position detection method and a position detection system.

[0002]

2. Description of the Related Art When photographing in a studio, a mobile camera system is used in which a camera platform is mounted on a moving platform called a pedestal and a camera is mounted on the platform. Then, in photographing, the photographer performs photographing while moving the pedestal and appropriately changing the camera angle.

For example, in a virtual studio,
Live-action video captured by the camera system in the studio,
When linking the computer graphics (CG) generated as the background or as an effect while maintaining the three-dimensional positional relationship viewed from the camera position, the planar position of the pedestal in the virtual space, Techniques for knowing the position and angle of a camera mounted on a pedestal have been applied. That is,
Once the planar position of the pedestal and the position and angle of the camera are determined, the pedestal, camera, subject, CG
Can be calculated, and the subject of the camera and the CG can be linked while maintaining the three-dimensional positional relationship.

[0004] The following is known as a technique in consideration of the above. (1) A method in which a number of position markers are provided on the studio ceiling, and a sensor attached to the pedestal reads a plurality of position markers and processes the images to recognize the planar position of the pedestal. (2) A method in which a marker is mounted on the pedestal and a plurality of detection cameras in the studio read the marker to detect the position of the pedestal. (3) A method of knowing the current position by reading a symbol (bar code) included in a blue-back image of the background of the studio camera and performing image processing on the appearance. (4) A method of laying rails in a studio and mounting a pedestal to detect a moving distance.

[0005]

However, each of the above prior arts has the following disadvantages. First, in the technique (1), the position marker may not be read from the pedestal position in some cases. That is, usually, a large number of certification devices are hung on the studio ceiling, and there are drawbacks such as that the field of view is physically blocked or that the reading of the position marker is obstructed by the light of illumination.

[0006] The technique (2) requires a large number of detection cameras to increase the detectable range, and is expensive.

In the technique (3), the symbols included in the background image must always be in the field of view of the camera, and there is a limit on the range in which the symbols can be moved. Also, if the subject becomes large in the video, such as when zooming up, the ratio of the symbols included in the background video in the video may decrease, and detection may not be possible.

The technique (4) has a drawback that the camera can only move on a fixed rail and is not applicable.

In any of the above techniques, it is difficult to obtain the positional relationship between the camera and the subject with high accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is an imaging method and an imaging system capable of grasping the positional relationship between a camera and a subject with high accuracy at low cost and without being restricted by imaging. The purpose is to provide.

[0011]

According to one aspect of the present invention, there is provided an imaging method for imaging a subject by a camera mounted on a movable gantry via a camera platform. A step of setting a reference position of a floor surface on which the movable gantry moves and a reference angle of the movable gantry, and a step of detecting a movement amount of the movable gantry from the reference position and a rotation angle from the reference angle, A step of obtaining the position and angle of the camera with respect to the subject from the reference position and reference angle and the amount of movement and the rotation angle of the movable gantry; and data of the position and angle of the camera with respect to the subject, an actual image of the subject by the camera. And sending the generated image to a computer.

According to another aspect of the present invention, there is provided an imaging system for imaging a subject, comprising: a camera unit having a camera mounted on a movable gantry via a camera platform; Calculating means for calculating the positional relationship between the movable gantry and the object; setting means for setting the reference position of the floor on which the movable gantry moves and the reference angle of the movable gantry in the arithmetic means; and the movable gantry from the reference position Detecting means for detecting the amount of movement and the rotation angle from the reference angle, the arithmetic means, the position of the camera with respect to the subject from the movement amount and the rotation angle of the reference position and the reference angle and the movement gantry and Calculate the angle,
There is provided an imaging system for transmitting data of a position and an angle of a camera with respect to the subject to a computer for creating a video including an actual image of the subject by the camera.

According to still another aspect of the present invention, there is provided an imaging system for imaging an object, comprising a movable gantry having three wheels, and a camera for imaging the object on the movable gantry via a camera platform. A camera unit configured to calculate the positional relationship between the camera and the subject; three encoders provided on each of three wheels of the movable gantry; and the movable gantry provided on the movable gantry. A plurality of sensors for detecting a predetermined mark on the moving floor, and the reference position of the floor and the reference position obtained by the number of pulses counted by the encoder and the detection value of the sensor when the moving gantry is moved. A setting unit for setting a reference angle of a movable gantry in the calculation unit, wherein the calculation unit counts the reference position and the reference angle and the encoder. Calculates the position and angle of the camera with respect to the subject from the amount of movement and the rotation angle of the movable gantry obtained from the number of pulses; An imaging system for transmitting the image data to a computer that generates the image data is provided.

According to the present invention, the reference position is set on the floor on which the movable gantry moves, the amount of movement of the gantry from the reference position and the rotation angle from the reference angle are detected, and the reference position, the reference angle and the movement are determined. Since the position and angle of the camera with respect to the subject are determined from the amount of movement of the gantry and the rotation angle, it is possible to determine the positional relationship between the camera and the subject without using particularly expensive equipment and without being restricted by imaging. it can. In addition, since the movable base can move at random, it has high applicability. In addition, since the errors associated with changes in the diameter of the mobile gantry and changes in the angle of the mobile gantry are small, the position and angle of the mobile gantry can be accurately determined, and a video containing a real image of the subject captured by the camera is created with high accuracy. can do.

In the present invention, the amount of movement of the movable gantry is preferably determined by measuring the length of a portion where the wheels of the movable gantry contact the floor. Thereby, the moving distance of the movable gantry can be accurately obtained.

Further, the rotation angle of the movable gantry can be calculated from the moving distance of two of the at least three wheels of the movable gantry that are separated in the moving direction.
Thereby, the angle of the movable gantry can be obtained accurately. Further, by selecting the most distant wheel set as the two wheels, the angle of the movable gantry can be more accurately determined.

Further, the reference position and the reference angle of the movable gantry form first and second lines on the floor surface so as to be orthogonal to each other from the reference position, and two first lines for detecting the first line. A sensor and a second sensor for detecting a second line are attached to the movable base;
It can be determined based on the amount of movement when each of the first sensors passes through the first line and the amount of movement when the second sensor passes through the second line. Thereby, the reference position and the reference angle of the movable gantry can be obtained relatively easily.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a side view of a TV camera unit used in the imaging method of the present invention, and FIG. 2 is a plan view thereof. The TV camera unit 1 includes a pedestal 2 as a movable platform that travels on the floor of a studio, a platform 3 provided thereon, and a T mounted on the platform 3.
And a V camera 4. The TV camera 4 can be turned and tilted by the camera platform 3. Reference numeral 5 denotes a handle for changing the moving direction of the pedestal, and 6 denotes a lever for tilting or turning the TV camera 4.

The pedestal 2 is provided with three traveling wheels 7a, 7b, 7c at the bottom. Also, on the bottom of the pedestal 2, two first optical sensors 8a and 8b and one second optical sensor 9 used for setting or correcting the reference position and the reference angle of the pedestal 2 are provided.
Is provided.

Next, the TV camera unit 1 as described above
An imaging system according to the present embodiment using the method and an imaging method using the same will be described with reference to the block diagram of FIG. 3 and the flowchart of FIG.

The wheels 7a, 7b, 7c of the pedestal 2
The encoders 11a, 11b, 11c for grasping the traveling distances (movement amounts) are connected to the rotating shafts. The encoders 11a, 11b, 11c, the first optical sensor 8a, 8b, and the second optical sensor 9 are connected to the reference setting unit 12, and are connected to the encoder 11a, 11b, 11c and the first optical sensor. Based on the information from 8a, 8b and the second optical sensor 9, the reference position of the floor on which the pedestal 2 runs and the reference angle of the pedestal 2 are determined by the reference setting unit 12 as described later, and the information is obtained. This is set in the calculation unit 13 (STEP 1 in FIG. 4). In addition, the calculation unit 13 includes a steering wheel angle of the pedestal 2, pan, tilt, and T of the pan head 3.
Zoom and focus data of the V camera 4 are also input.

When the pedestal 2 travels on the floor, the wheels 11a, 11b, 11c are driven by the encoders 11a, 11b, 11c.
The traveling distance (movement amount) of 7c is grasped, and the operation unit 13 detects the movement amount of the pedestal 2 from the reference position and the rotation angle from the reference angle from these values (STEP2 in FIG. 4).

The arithmetic unit 13 calculates the position and angle of the TV camera 4 with respect to the subject from the reference position and reference angle data from the reference setting unit 12 and the rotation amount of the pedestal 2 and the reference angle. The calculation is performed (STEP 3 in FIG. 4).

The data on the position and angle of the TV camera 4 with respect to the subject calculated by the calculation unit 13 are sent to the image forming computer 14 (STEP in FIG. 4).
4). In the image forming computer 14, for example,
As shown in FIG. 5, it is possible to link the real image (the object point 20) of the TV camera 4 with the virtual image projected on the virtual screen 30 of the background.

The movement of the pedestal 2 is performed by using the encoders 11a, 11b, 11c attached to the rotating shafts of the wheels 7a, 7b, 7c as described above. here,
When measuring the amount of movement using an encoder, it is generally obtained by dividing the diameter of the wheel by the number of pulses per revolution detected by the encoder, but the wheel (normally three wheels) of the bogie of the pedestal 2 is generally It is made of rubber, and the contact state with the floor changes when the wheel goes straight and turns,
The tire diameter at the contact portion changes. Therefore, when the movement distance is measured from the rotation of the shaft and the diameter of the wheel in this way, an error occurs and the measurement is inaccurate.

In order to avoid such a problem, in this embodiment, as shown in FIG. 6, a roller 15 having a known diameter is attached to a wheel (wheel 7a in the figure). In this case, since the roller 15 rotates according to the rotation of the wheel,
If the number of rotations of the roller 15 is known, the length of the portion where the wheel contacts the floor can be accurately grasped regardless of the state of the wheel. That is, if the diameter of the roller 15 is divided by the number of pulses per rotation, the movement amount of the roller 15 is calculated. Even if the wheel is worn, as long as the roller 15 is in contact with the wheel, the calculated value is obtained. , The amount of wheel movement can be accurately grasped.

Next, a method of recognizing the reference position of the floor on which the pedestal 2 runs and the reference angle of the pedestal 2 and setting the reference position in the calculation unit 13 will be described. As shown in FIG. 7A, the X-axis and the Y-axis are set with the reference position on the floor as the origin.
A shaft is formed, and the pedestal 2 is driven. And the first
When the optical sensors 8a and 8b pass through the X axis which is the Y origin, the angle correction and the Y origin are determined based on the count difference by the encoders 11a and 11b of the wheels 7a and 7b. Next, based on the position at the moment when the second optical sensor 9 passes through the X origin, the X origin position is determined by the current angle correction value. Here, for convenience, the first optical sensors 8a and 8b and the second optical sensor 9 are indicated by arrows in the direction of the line to be detected.

Next, a specific angle correction calculation method will be described with reference to FIG. Here, the cut angle of the handle 5 is θ, the distance between the two first optical sensors 8a and 8b is M, and a line connecting the centers of the first optical sensors 8a and 8b and the second optical sensor 9 is shown. Is S.
First, the pedestal 2 is arranged near the initially set origin. Next, the first optical sensors 8a and 8b are driven to cross the X axis, and the rotation angle Δθ of the pedestal when the first optical sensor 8b crosses the X axis is obtained. The state at this time is as shown in FIG. now,
By the time the first optical sensor 8b crosses the X axis, the wheels 7a,
Assuming that the distance traveled by 7b is a and b, respectively, Δθ, ΔX, and ΔY in FIG. 7B are given by the following equations. Δθ = tan ⁻¹ ((ab) · cos θ / (M− (a
−b) · sin θ)) ΔY = (M / 2) · sin Δθ ΔX = S · sin Δθ

Here, since a and b are obtained by counting the encoders 11a and 11b attached to the wheels 7a and 7b, the rotation angle Δθ of the pedestal 2 is also obtained.

Then, the pedestal 2 is made to travel a further small distance, a new Δθ is calculated from the newly obtained values of a and b, and added to the previously obtained Δθ to travel a further small distance. The rotation angle at the time is known, and the position at the time when the vehicle travels a short distance from the newly obtained a, b and Δθ is also known. Hereinafter, by repeating this operation, the position and rotation angle of the pedestal 2 can be always known.

Further, a highly accurate reference position setting (origin correction)
As shown in FIG. 8, it is preferable to create a reference position passing point by combining two types of plate members (for example, hard vinyl chloride plates) 21 and 22 having different colors.
Thereby, horizontal and vertical are guaranteed by the accuracy of the cut surface of the plate material, and the reference position can be set with high accuracy.

The rotation angle of the pedestal 2 is
May be calculated as follows from the difference between the moving distances of two of the three wheels. Δθ = tan ^-1 {(ab) / N} where two wheels are wheels 7a and 7b,
N is the distance between the wheels 7a and 7b.

The above description focuses on the pair of wheels 7a, 7b
This is the result of obtaining X, ΔY, and Δθ, but the same applies when focusing on another pair of three wheels (a pair of wheels 7b and 7c, a pair of 7a and 7c) if they are separated from each other in the moving direction. The position and angle can be calculated by the following method.

The present embodiment has a feature in the method of selecting the two wheels at this time, and selects the wheel that is farthest from the traveling direction. Specifically, as shown in FIG. 9, straight lines L1, L2, L3 passing through the centers of the three wheels 7a, 7b, 7c and parallel to the traveling direction are drawn. The distance Na between L1 and L2, the distance Nb between L2 and L3, and the distance Nc between L3 and L1 are determined, and the set of wheels having the longest distance is selected. In the case of FIG. 9, since the distance Nb is the longest, the wheels 7b and 7c are selected. Thus, the rotation angle can be calculated with high accuracy.

In this case, since the traveling direction is determined by the turning angle of the annular handle 5 installed on the pedestal 2,
The calculation target wheel may be preset so that it is automatically selected according to the turning angle of the handle 5, or the optimum wheel may be selected by a computer mounted on the pedestal 2.

The present invention can be variously modified without being limited to the above embodiment. In the above embodiment, the synthesis of the real video and the virtual video is taken as an example. However, the present invention is not limited to this, and can be applied to the synthesis of the real video. In addition, video synthesis can be applied in either real time or later editing. Further, the shape of the pedestal is not limited to the above embodiment, and the number of wheels of the pedestal may be more than three. Furthermore, the method of detecting the movement amount, the method of setting the reference position and the reference angle, and the like are not limited to the above embodiment.

[0037]

As described above, according to the present invention,
A reference position is set on the floor on which the mobile gantry moves, and the amount of movement of the mobile gantry from the reference position and the rotation angle from the reference angle are detected. Since the position and angle of the camera with respect to are grasped, the positional relationship between the camera and the subject can be grasped without using specially expensive equipment and without being restricted by imaging. In addition, since the movable base can move at random, it has high applicability. In addition, since there is no error due to changes in the diameter of the mobile gantry or changes in the angle of the mobile gantry, the position and angle of the mobile gantry can be accurately grasped. Can be created with

[Brief description of the drawings]

FIG. 1 is a side view of a TV camera unit used in an imaging method according to the present invention.

FIG. 2 is a plan view of a TV camera unit used in the imaging method of the present invention.

FIG. 3 is a block diagram showing an imaging system according to an embodiment of the present invention.

FIG. 4 is a flowchart for explaining the imaging method of the present invention.

FIG. 5 is a schematic diagram for explaining a state in which an actual image formed by a TV camera and a virtual image projected on a virtual screen in the background are linked using the method of the present invention.

FIG. 6 is a view for explaining a method of obtaining a moving distance of a wheel according to the embodiment.

FIG. 7 is a diagram for explaining a method of recognizing and setting a reference position of a floor surface on which the pedestal runs and a reference angle of the pedestal, and a specific pedestal angle correction calculation method.

FIG. 8 is a view for explaining an example of a preferred reference position passing point.

FIG. 9 is a diagram showing a second example used to calculate the rotation angle of the pedestal.
The figure for explaining how to choose one wheel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... TV camera unit 2 ... Pedestal 3 ... Head head 4 ... TV camera 5 ... Handles 7a, 7b, 7c ... Wheels 8a, 8b ... First optical sensor 9 ... Second optical sensor 11a, 11b, 11c ... Encoder 12 ... Reference setting unit 13 ... Calculation unit 14 ... Image forming computer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Iwao Fujita 6-10-10 Futako, Takatsu-ku, Kawasaki City, Kanagawa Prefecture Inside Sho Toku Seisakusho Co., Ltd. (72) Naoki Ebimoto 6, Futako 6, Takatsu-ku, Kawasaki City, Kanagawa Prefecture No. 10-10 Inside Sho Toku Seisakusho Co., Ltd. (72) Hiroyuki Tanaka Inventor 5-3-6 Akasaka, Minato-ku, Tokyo Inside Tokyo Broadcasting Corporation (72) Inventor Tadao Matsuno 5-36 Akasaka, Minato-ku, Tokyo No. F term in Tokyo Broadcasting Corporation (reference) 2H105 AA06 EE16 5C022 AB62 AB65 AB68 AC27 AC31 AC74 CA02 CA03

Claims (13)

[Claims] 1. An imaging method for imaging a subject by a camera mounted on a movable gantry via a camera platform, wherein a reference position of a floor on which the movable gantry moves and a reference angle of the movable gantry are set. Detecting the amount of movement of the movable gantry from the reference position and the rotation angle from the reference angle; and the reference position and the reference angle as well as the amount of movement of the gantry and the rotation angle of the camera from the camera relative to the subject. An imaging method comprising: a step of grasping a position and an angle; and a step of transmitting data of a position and an angle of a camera with respect to the subject to a computer that creates an image including a real image of the subject by the camera. . 2. The imaging method according to claim 1, wherein the amount of movement of the movable gantry is obtained by measuring a length of a portion where the wheels of the movable gantry contact the floor. 3. The moving gantry has at least three wheels, and the rotation angle is calculated from a moving distance of two wheels separated from each other in the moving direction. The imaging method according to claim 1. 4. The imaging method according to claim 3, wherein a pair of wheels that are most distant from each other is selected as the two wheels. 5. The first sensor according to claim 1, wherein the reference position and the reference angle form first and second lines on the floor surface so as to be orthogonal to each other from the reference position and detect the first line. And one second sensor that detects a second line is attached to the movable base, and the two first sensors
2. The movement amount when each of the sensors passes through the first line, and the movement amount when the second sensor passes through the second line. The imaging method according to claim 1. 6. An image capturing system for capturing an image of a subject, comprising: a camera unit having a camera mounted on a movable gantry for capturing an image of the subject via a camera platform; and a calculation for calculating a positional relationship between the camera and the subject. Means, setting means for setting a reference position of the floor surface on which the movable gantry moves and a reference angle of the movable gantry in the calculating means, a moving amount of the movable gantry from the reference position and a rotation from the reference angle Detecting means for detecting an angle, wherein the calculating means calculates a position and an angle of the camera with respect to the subject from the reference position and the reference angle and a moving amount and a rotation angle of the movable gantry, and the camera for the subject is calculated. And transmitting the data of the position and the angle to a computer that creates a video including an actual image of a subject by the camera. Image system. 7. The imaging system according to claim 6, wherein the setting unit includes a reference detection mechanism that detects a reference position on a floor surface on which the movable gantry moves and a reference angle of the movable gantry. 8. The apparatus according to claim 6, wherein the detecting means obtains the amount of movement of the movable gantry by measuring a length of a portion of the movable gantry where the wheels contact the floor. 3. The imaging system according to claim 1. 9. The moving gantry has at least three wheels, and the detecting means has at least three encoders for grasping a moving distance of each of the wheels accompanying the movement of the moving gantry. The imaging system according to claim 6, wherein the imaging system performs the processing. 10. The method according to claim 6, wherein the rotation angle is calculated from a movement distance obtained by encoders provided on two wheels separated from each other in the movement direction. The imaging system according to claim 1. 11. The imaging system according to claim 10, wherein a pair of wheels that are most distant from each other is selected as the two wheels. 12. A method according to claim 1, further comprising: a roller which is in contact with each of said wheels and which rotates according to the rotation of said wheel, and wherein the moving distance of each of said wheels is obtained from the number of rotations of said roller and the number of pulses counted by said encoder. The imaging system according to claim 6. 13. An imaging system for capturing an image of a subject, comprising: a movable gantry having three wheels; a camera unit having a camera mounted on the movable gantry via a pan head; A calculating unit for calculating a positional relationship between the moving gantry and a subject; three encoders provided on each of three wheels of the moving gantry; a predetermined mark provided on the moving gantry and on a floor surface on which the moving gantry moves A plurality of sensors for detecting the reference position of the floor surface and the reference angle of the movable gantry grasped by the detection value of the sensor when the movable gantry is moved and the number of pulses counted by the encoder. And a setting unit that sets the reference position and the reference angle and the number of pulses counted by the encoder. The computer calculates the position and angle of the camera with respect to the subject from the movement amount and rotation angle of the movable gantry, and converts the data of the position and angle of the camera with respect to the subject to a computer that creates an image including a real image of the subject by the camera. An imaging system characterized by transmitting.