JPH0666967B2 - Convergence angle controller for stereoscopic camera - Google Patents

Description

The present invention relates to a convergence angle control corresponding to a shooting distance of a television camera for stereoscopic image shooting.

[Conventional technology]

Conventionally, when a stereoscopic image is captured by a stereoscopic image capturing television camera, a system using two left-eye and right-eye television cameras, or a prism is used to divide an image into two for the left-eye and the right-eye. In both methods of realizing a stereoscopic image with a camera, the expected angle of the optical axis between the left-eye and right-eye images was fixed. Even if the vergence angle is variable, the vergence angle was adjusted by a cameraman, and there was no fixed law.

[Problems to be solved by the invention]

When a human sees a landscape, it controls the vergence angle of both eyes (the angle at which the eyes of the left eye and the right eye respectively add up and the gaze of the visual object) depending on the distance of the visual object, and also adapts to the visual distance. By adjusting the focal length of the crystalline lens, a natural three-dimensional effect is obtained.

However, in the conventional method of capturing a stereoscopic image, the convergence angle of the photographing camera corresponding to the images for the left eye and the right eye is fixed or uses a value obtained by trial and error experience.

As a result, some images have a natural three-dimensional effect,
At a place farther or closer than that, the stereoscopic effect is abnormally emphasized, or a stereoscopic fusion (left eye and right eye) occurs due to parallax (difference between images displayed by the left and right cameras). However, there is a problem in that the image given to (1) cannot be obtained as a single image with a three-dimensional effect that fuses in my head.

In order to reduce these inconveniences, Japanese Patent Application No. 57-139891 (Japanese Patent Application Laid-Open No. 59-30389) already filed proposes a method of changing the angle (convergence angle) between the left and right cameras depending on the shooting distance. ing.

However, a drawback of this method is that the angle between the left and right cameras is geometrically determined from the distance of the object to be photographed.

Therefore, the nature of vergence eye movement of a human being, for example, in an imaging target at a certain distance or more, the lines of sight of the left eye and the right eye are parallel. Alternatively, when it comes to a close view, there is a property that the vergence angle does not change any more, that these correspondences are not always effectively considered, and because the time constant of the human vergence eye movement is also not considered. , When the angle between the cameras is controlled and changes, the viewer's vergence eye movement cannot follow, which causes discomfort.

Therefore, the object of the present invention is to solve the above-mentioned inconveniences, in accordance with the vergence angle of the viewer to the visual target, by appropriately controlling the vergence angle of the photographing camera, images for the left eye and the right eye are displayed. An object of the present invention is to provide a vergence angle control device for a stereoscopic image camera capable of capturing an image.

[Means for solving problems]

In order to achieve such an object, in the present invention, in accordance with the data of human convergence eye movement, by the shooting distance, for example, to appropriately control the convergence angle of the left and right cameras and the time constant for its adjustment. To do.

That is, the present invention relates to a photographing camera that photographs two images for the left eye and the right eye, a measuring unit that measures the distance to the photographing object, and a photographing camera that intersects the optical axes of the two images. Measuring means for measuring the vergence angle, a vergence angle at which a human stereoscopically sees with the left eye and the right eye look at the visual target, and storage means for storing data of the distance from the eye to the visual target And the data stored in the storage means,
Computation means for computing the vergence angle from the value of the distance measured by the measurement means, the vergence angle computed by the computation means, and a comparison means for comparing the vergence angle of the photographing camera measured by the measurement means, It is characterized in that it is provided with an integrating means for integrating the output taken out from the comparing means and a means for controlling and adjusting the vergence angle of the photographing camera by the output from the integrating means.

[Action]

According to the present invention, according to the experimental data of human convergence eye movement, according to the shooting distance, the convergence angle of the shooting camera for the left eye and the right eye is made variable, and further the response time constant is appropriately controlled and adjusted. can do.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings.

Here, first, before entering the description of the embodiment according to the present invention,
The relationship between the vergence angle and the object to be photographed and the characteristics of binocular vision will be described in detail.

2 (A), (B) and (C) are explanatory views showing the relationship between the angle of convergence and the object to be photographed.

FIG. 2A is an explanatory diagram showing the angle of convergence of the stereoscopic camera (imaging device). FIG. 2B is an explanatory diagram showing the vergence angle of the human eye. The eyes of both eyes add in order to match the line of sight with the target. The angle formed by the lines of sight of both eyes at this time is the angle of convergence. In FIG. 2 (A), the angle θ formed by the optical axes of the left and right cameras is defined as the convergence angle of the camera for convenience.

The big difference between the stereoscopic image projected on the screen and the case of observing a natural image is that when observing a natural image, the parallax changes depending on the distance between the eye and the visual target, whereas in the stereoscopic image, The difference between images displayed by the left and right cameras (parallax) is always constant on the screen.

Therefore, in the case of a stereoscopic image, since the deviation between the left and right images on the screen is constant, the appearance of the stereoscopic image, that is, the stereoscopic effect greatly changes depending on the distance between the viewer and the screen.

From this, when producing a stereoscopic image, it is necessary to set a standard viewing distance in advance and notify the observer in order to correctly convey the stereoscopic effect intended by the producer. . Here, as an example of the standard viewing distance, 6H (6 times the height H of the video screen) in the current television standard system and 3H in the high definition system are suitable.

FIG. 2 (C) shows the convergence angle when a stereoscopic image is observed by changing the distance x between the image on the screen and the eye.
It shows that the angle φ is not necessarily the same as θ ′ shown in (B).

FIG. 3 is a characteristic diagram showing a correlation between the visual distance and the vergence angle, which was tested by observing how the vergence angle of the eye changes when the bar is placed in front of the face and the gaze of the stick is performed depending on the visual distance.

In the figure, the curve connecting the □ marks is the convergence angle obtained geometrically on the assumption that the line of sight faithfully faces the visual target.

Regarding the measurement examples that were tested, there is a slight difference in the phoria depending on the individual, and it cannot be said that all of them necessarily have such curves, but the common point is that the vergence angle becomes 0 at a visual distance of about 3 m. , The lines of sight of both eyes are parallel,
It can be said that the vergence angle does not become larger than this value when approaching from 40 to 60 cm. This fact is different from the vergence angle calculated geometrically from the visual distance, and is an important factor for realizing a vergence angle control system adapted to the human system.

FIG. 4 is a characteristic diagram showing the adjustment of the focal length of the crystalline lens and the step response of the vergence angle in the case of binocular vision when observing a natural image. In FIG. 4, the focal depth of the visual target is shown. Two
The response is shown when the step change is made from D (deopter) to 3.5D.

The time constant of the convergence angle response is larger than that of the adjustment response, and its value is
It can be seen that it is 0.6 to 0.8 seconds.

Also, as can be seen from FIG. 4, the adjustment response and the convergence angle response are
Perform a co-ordinated movement related to each other. When viewing a binocular stereoscopic image, it can be considered that the distance between the screen (CRT) and the observer is always constant. Therefore, while observing a stereoscopic image, the focal length of the crystalline lens should not change,
When a stereoscopic image is presented and a vergence movement occurs corresponding to the displacement (parallax) of the left and right images on the screen, the focal length of the crystalline lens also changes. That is, as the angle of convergence increases, this corresponds to looking closer and the lens becomes thicker. On the other hand, as the vergence angle becomes parallel, the crystalline lens becomes thinner corresponding to the further viewing. These changes in the lens naturally cause blurring of the image, resulting in a force that returns the lens to a thickness corresponding to the original viewing distance. Therefore,
Eye strain occurs in the lens regulatory system, which eventually leads to mental fatigue.

In order to minimize this fatigue, the distance to the position corresponding to the center of the convergence angle change range of the stereoscopic image presented by the observer (≈the center of the adjustment change range) is the standard viewing distance of the screen or CRT, such as a television. 6H for the John standard system, and 3H for the high-definition system.

Here, when shooting an object in which the distant view and the near view are evenly present, the image of the object at about 1.8 m, which is in the middle of the range of 0.5 to 3 m in which vergence motion occurs, has no parallax on the screen, that is, on the right. If the television standard method is 6H and the high-definition method is 3H so that the image and the left image match, it is converted into a convergence angle, and if the convergence angle is used for shooting,
It is considered that a natural stereoscopic image can be obtained with no discomfort with the control system.

In the case of actually shooting a program, the distribution of shooting distance may be biased in a studio or the like such as only a close view, and the standard convergence angle is in the middle of the back and front of the shooting target ( Make sure there is no parallax on the screen of the image of the object in the depth center.

FIG. 5 is a characteristic diagram showing the relationship between the shooting distance d and the convergence angle θ of the camera.

The figure shows an example of data in the case where an image whose depth center of the shooting target is 1.5 m is displayed at a standard viewing distance of 6H. The vergence angle of 1.5m in natural vision is point A, but this is 6H
In order to shoot at the convergence angle of point B corresponding to (corresponding to 1.8 m in the case of 21 inch monitor), as shown in the figure,
The viewing distance vs. vergence angle data (solid line in the figure) in FIG. 3 is converted into a curve indicated by a broken line so that the vergence angle B becomes 1.5 m. In this case, the stereoscopic effect is suppressed. The convergence angle corresponding to the shooting distance can be calculated based on this conversion data.

The relationship between the vergence angle by the binocular vision of a human and the vergence angle of the camera for capturing a stereoscopic image has been described above in detail, and the embodiment will be described in detail below based on these.

Therefore, FIG. 1 is a block diagram showing the configuration of an embodiment according to the present invention.

In FIG. 1, 1 and 2 are left and right photographing cameras, and 0 is a photographing target. A distance measuring device 3 measures the distance between the photographing cameras 1 and 2 and the photographing target 0.

Reference numeral 4 is a potentiometer, and 4A is an A / D converter, which detects the angle of convergence of the photographing cameras 1 and 2 and outputs digital data. A motor 5 controls the angle of convergence of the photographing cameras 1 and 2.

A CPU 6 and a ROM 6A calculate a desired convergence angle θ from the distance d between the photographing cameras 1 and 2 and the photographing target 0 measured by the distance measuring device 3.

Reference numeral 7 denotes an input device, which specifies a distance for viewing a stereoscopic image and inputs it to the CPU 6. Reference numeral 8 is a three-dimensional amount control circuit, which generates a coefficient α for controlling the strength of the three-dimensional effect. Reference numeral 9 is a comparator that detects a difference Δθ from a desired convergence angle.

Reference numeral 10 is an integrator, and 11 is a drive circuit, which drives the motor 5 in accordance with the time constant determined by the integrator 10.

The operation of this embodiment will be described below.

First, the distance measuring device 3 measures the distance d between the photographing cameras 1 and 2 and the photographing target 0, and the data is sent to the CPU 6. In this case, the viewing distance of the image projected on the screen has already been specified and is input from the input device 7 to the CPU 6. The CPU 6 refers to a table stored and stored in advance from the ROM 6A to calculate and output a convergence angle θ corresponding to the shooting distance d and the viewing distance.

The vergence angle θ output from the CPU 6 is given to the comparator 9.
On the other hand, the vergence angle detected by the potentiometer 4 is converted into digital data θ ₁ by the A / D converter 4A and given to the comparator 9. Further, the three-dimensional amount control circuit 8 provides the comparator 9 with a three-dimensional amount control coefficient α that provides an appropriate three-dimensional effect.

In the comparator 9, a desired adjustment angle Δθ = α (θ is calculated based on the above-mentioned input convergence angle data θ ₁ and θ and the stereoscopic control coefficient α.
−θ ₁ ) is detected.

The output Δθ detected by the comparator 9 is sent to the integrator 10, and a predetermined time constant is set. The output of the integrator 10 is the drive circuit 11
The motor 5 is driven with an appropriate time constant to control the convergence angle θ of the photographing cameras 1 and 2.

〔The invention's effect〕

As is apparent from the above, according to the present invention, it is possible to capture the captured images for the left and right eyes so that a stereoscopic image close to natural vision can be obtained according to the movement of the human eye.

Furthermore, according to the present invention, by a simple operation,
Moreover, it is possible to automatically take a proper stereoscopic image.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIGS. 2 (A) to (C) are explanatory diagrams showing the relationship between the vergence angle and a photographing (visual) object, and FIG. 3 is a visual distance. FIG. 4 is a characteristic diagram showing a correlation of vergence angles, FIG. 4 is a characteristic diagram showing adjustment and step response of vergence angles when viewing with both eyes, and FIG. 5 is a characteristic diagram showing a relationship between a shooting distance d and a vergence angle θ of the camera. Is. 1, 2 ... Shooting camera, 3 ... Distance measuring device, 4 ... Potentiometer, 4A ... A / D converter, 5 ... Motor, 6 ... CPU, 6A ... ROM, 7 ... Input device, 8 ... 3D control circuit, 9 ... comparator, 10 ... integrator, 11 ... drive circuit.

Claims (1)

[Claims] 1. A photographing camera for photographing two images for a left eye and a right eye, a measuring means for measuring a distance to a photographing object, and a photographing camera for intersecting respective optical axes for photographing the two images. Measuring means for measuring the vergence angle, storage means for storing and storing data of the vergence angle at which the line of sight stereoscopically viewed by a human with the left and right eyes looks at the visual target, and the distance from the eye to the visual target With the data stored in the storage means, a calculating means for calculating the convergence angle from the value of the distance measured by the measuring means, a convergence angle calculated by the calculating means, and the measuring means A comparing means for comparing the measured convergence angle of the photographing camera, an integrating means for integrating the output taken out from the comparing means, and an output from the integrating means for controlling and adjusting the convergence angle of the photographing camera. Do Convergence angle control device for stereoscopic picture camera, characterized in that it comprises a stage.