JP2001056450A - Stereoscopic picture reproducing device using optical filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stereoscopic picture reproducing device using an optical filter which is different from a light beam reproducing method but which is set on the extension thereof and which is constituted so that the blurring of a picture caused by the spread of a light beam can be reduced. SOLUTION: This stereoscopic picture reproducing device using the optical filter is provided with a white irradiation light source 21, three-dimensionally uniformly distributed white foggy light scattering bodies 22, a pinhole array 23 and a light beam weighing filter 24 having a function executing the spatial weighing of intensity and color with respect to a light beam group passing through the array 23 out of the light beams scattered from the bodies 22. Thus, the bodies 22 can be viewed so that they are not the uniform white foggy bodies but they are the threedimensional bodies having shape and color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional image reproducing apparatus using an optical filter belonging to the fields of video technology, broadcasting technology, art industry, multimedia industry, camera, photography and the like.

[0002]

2. Description of the Related Art Conventional three-dimensional image recording / reproducing technology basically records a three-dimensional image by some method and reproduces the three-dimensional image.
A method in which the observer observes the image as it is, instead of recording a stereoscopic image, a plane image for the right eye and left eye is recorded, and the right eye for the right eye and the left eye for the left eye are reproduced during playback. Can be roughly divided into two types of stereoscopes.

[0003] Representative examples of the former are holograms and integral photography, and representative examples of the latter include a stereoscopic movie using polarized glasses and a stereoscopic television using lenticulars.

In the latter case, since the image looks three-dimensional but does not reproduce a three-dimensional image, the image does not change even if the viewing position is changed, and it cannot be said that the back side is visible. .

In holography, the appearance changes when the viewing position is changed, and a well-formed object is an ideal three-dimensional stereoscopic image recording / reproducing method (hereinafter, referred to as an object) that looks as if there is actually an object there.
3D image is abbreviated as 3D image). In this holography, wavefront information of light from an object is used to record stereoscopic image information. The wavefront information is recorded by causing the reference light and the scattered light from the object to interfere with each other and recording the interference fringes.

For this reason, the optical system and the recording medium need to have a spatial resolution close to the optical wavelength, and at least a coherent light source such as a laser is required for recording. 1,000 lines / m for film for recording and reproduction materials
m or more. For example, if a liquid crystal is used, a very large number of pixels are required, which is expensive and economically problematic as well as technically problematic.

It is even more difficult with moving pictures. Further, since the interference fringe depends on the wavelength, a color image cannot be handled as it is, and color recording requires not only three coherent light sources of three primary colors but also a complicated device.

For these reasons, holography is used for recording media for digital information other than for credit cards and ornaments, but has not been used for real-time 3D image display or stereoscopic movies.

[0009] Integral photography is the same as a stereoscope in that a stereoscopic image is obtained by parallax, but the stereoscope observes images from two viewing angles with both eyes, and obtains a stereoscopic effect from the binocular parallax. On the other hand, an image from a multi-viewing angle is recorded, and a large number of images having different views depending on the viewing position are reproduced based on the image.

Therefore, there is an advantage that the appearance changes when the eye is moved, and no glasses are required. Furthermore, it has many advantages over holography, such as being able to record and reproduce with ordinary light and reproducing scenery at infinity. There are some modifications, and experiments are being conducted on not only the left and right but also the three dimensional ones up and down, the left and right only, the projection type as well as the direct-view type, and even those capable of TV display.

In integral photography, images at all viewing angles are multiplexed and formed at a certain position (of course, only one image can be seen from a specific direction). Since it looks as if it were at the position, the focus position and the visible position do not match, and the unnaturalness is inevitable (for example, even if the image is seen in front of the eyes, the eyes are focused far away).

[0012] Although image recording from multiple viewing angles can be easily performed by a microlens array, when the image is reproduced in the reverse process, the view from the front is viewed from the back (the face can be seen when the face is reproduced, but the nose is concave). ), Which has the disadvantage of requiring a lot of trouble such as a troublesome turning operation.

On the other hand, the stereoscope type is used for expositions, etc.
It is common and enjoyable, but the lack of glasses is still lacking in reality because it has many imperfections and is, after all, simulated. Further, similarly to integral photography, it has a drawback that the focus position and the visible position are different.

In any case, at present, there is no 3D image recording / reproducing apparatus or system which is sufficiently practical, and the application is long-awaited.

[0015] Recording and reproduction of 3D images, particularly moving images, are the most important image information media, and are useful in various fields such as information, broadcasting, movies, and entertainment, and have the potential to become a large industry in the future. ,until now,
At home and abroad, many companies, universities, private and public research institutes have tried this, but at present there is no such thing.

[0016]

To overcome such a situation, the inventor of the present application first projects a group of light rays corresponding to scattered light from an object using a multi-viewpoint image group with a point light source array. A “light beam reproduction method” for artificially generating a 3D image by applying the method has been proposed and filed (Japanese Patent Application Laid-Open No. 10-239).
785).

According to this method, although similar to integral photography (IP) in that a multi-viewpoint image group is used, a 3D image itself having a depth is reproduced and parallax is not used. If you take a picture with the camera, it will be blurred except for the in-focus area.

Already a 3D image has been successfully generated with a simple object, but there remains problems such as sharpness of the image. This is because the light rays that make up the point image are light from independent point light sources.Therefore, mutual coherence is lacking, and the point image is a superimposition of the thickness of each light ray that is spreading by diffraction. There is a cause that it does not become.

The present invention eliminates the above-mentioned problems and is different from the light beam reproduction method, but is on an extension of the light beam reproduction method and uses a light filter capable of reducing the blur of an image due to the spread of light beams. The purpose is to provide.

[0020]

According to the present invention, there is provided a stereoscopic image reproducing apparatus using an optical filter.
A white illumination light source, a white cloud-like light scattering object having a three-dimensionally uniform distribution, a pinhole array, and a light beam passing through the pinhole array among scattered light from the white cloud-like light scattering object. A color transmission spatial distribution filter having a function of spatially weighting the intensity and the color, wherein the white cloud-like light scattering object is not a uniform white cloud-like object but has a three-dimensional shape and color. It is characterized by being made to look like an object.

[2] In the three-dimensional image reproducing apparatus using the optical filter according to [1], a plurality of one-to-one images may be provided between the white cloud-like light scattering object and the color transmission space distribution filter or further behind it. It is characterized by arranging two lenses.

[0022]

Embodiments of the present invention will be described below in detail.

The present invention is different from the light beam reproduction method, but is an extension of the light beam reproduction method, and is newly proposed to solve the problem. Therefore, first, the light beam reproducing method will be described.

FIG. 4 is a diagram showing the principle of stereoscopic vision.

Here, for simplicity, the object is shown by two points having different distances. That is, two point objects P and Q are considered. Since a general object is a group of point objects, it can be easily extended to a general object. Light rays reach the eyes of the observer 1 from different directions at different spread angles. The direction of the light beam provides two-dimensional position information, and the spread of the light beam causes a difference in the appearance (parallax) of the left and right eyes and a shift in focus, and gives distance information.

According to the "ray beam reconstruction method" of the above-mentioned prior application of the inventor of the present invention, at the observer, a group of rays as shown in FIG. It is a way to show.

Next, FIG. 5 shows a principle diagram of 3D image reproduction by the light beam reproduction method.

As shown in FIG. 5, the white point light source array 11
When the color filter 12 that can transmit only one point in the space is opposed to the color filter, a colored light ray that travels in a linear direction connecting the two points can be reproduced. If the color filter 12 is used in a planar manner, all rays from a virtual object (for example, P ′, Q ′) in front of the white point light source array 11 that pass through the point light source can be reproduced as much as possible.

As can be seen from a comparison between FIG. 4 and FIG. 5, when the system of FIG. 5 is used, the observer looks as if there is an object even though there is actually no object ahead in the reproduced light beam. become.

When the lens 13 is used as shown in FIG. 6, the observer 1 observes not the object but the 3D image formed by the lens 13. Also in this case, the light beam reproduction method can be used as shown in FIG. In FIG. 7, the point P, the light beam, and the lens in front of the white point light source array 11 do not actually exist, but are shown as if they were present by the observer 1, and are indicated by dotted lines. Although the image becomes an inverted image as it is, if the white point light source array 11 and the color filter 12 are simply rotated by 180 degrees, the image becomes an erect image (there is no need to make modifications as in the case of integral photography). Although a point image is seen in FIGS. 6 and 7, an arbitrary 3D image can be actually reproduced as shown in FIG.

In FIG. 8, the point light source array is a white light source 1.
4. A combination of a scattering plate (such as frosted glass) 15 and a pinhole array 16 is used instead.

The substance of the color filter 17 is a point light source section of the point light source array or the pinhole array 16 in FIG.
This is equivalent to the fact that a color image viewed as if there is an observation object from the pinhole portion is recorded as an inverted image, and is basically the same as the recorded image of integral photography.

That is, if a microlens is arranged in a point light source section or a pinhole section and an image is taken by a filter section,
It becomes a color filter. If you do not care about the resolution, if you record a pinhole photograph while keeping the pinhole, the ray trajectory is recorded as it is. CG (computer graphics) or animation, etc. do not actually shoot,
It can be calculated and drawn with a computer.

The present inventor has already succeeded in generating a reasonable color stereoscopic image by this method.

Next, problems of the light beam reproducing method will be described.

In the light beam reproduction method, as shown in FIG. 5, light coming from different point light sources is emitted from one point and spreads variously, or as shown in FIG. 7, it gathers at one point and spreads further from there. Yes, and observing it, it looks like there is one object there.

A disadvantage is that this one point does not become too small. It is natural that the light beam generated by the point light source and the filter spreads by diffraction. In addition, even if the light beams emitted from independent light sources are collected at one point, the temporal and spatial coherence (phase relationship) between the light beams is quite low. Since they are not, they will not be narrower than the width of each ray.

On the other hand, as shown in FIG. 4 or FIG.
Even if the light beam emitted from one point is white light, there is coherence between the light beams, and although it differs depending on the wavelength, it can be collected at a small point up to the point determined by the lens aberration and the diffraction limit, and can be observed as a small point. This is because FIGS. 4 and 6 show an actual point or an image of the point in a simple manner.

FIG. 1 is a block diagram of a three-dimensional image reproducing apparatus using an optical filter according to a first embodiment of the present invention. Here, a basic configuration without using a lens is shown.

A three-dimensional image reproducing apparatus using this optical filter receives a light from a white light source 21 and scatters white light in an arbitrary direction. Or a cloud-shaped distribution white light source) (WCSO) 2
2, a pinhole array 23, and a light weighting filter (LCF) 24.

Light rays scattered from the white cloud-like scattering object 22 and passing through the pinhole are cut off by the light weighting filter 24, or pass through with an appropriate intensity and color. Note that P 'and Q' are the observers 1
3 shows a three-dimensional reproduced image, and 25 denotes a reproduced light beam group.

Hereinafter, the operation principle of the three-dimensional image reproducing apparatus using the optical filter will be described.

When the light weighting filter 24 is made transparent, the observer 1 can observe the entire white cloud-like scattering object 22 in three dimensions. On the other hand, if a straight line is drawn from the specific point P 'in the WCSO 22 to each pinhole of the pinhole array 23 and only the point of the LCF 24 on the extension is made transparent, only the light rays coming from the specific P' point will be observable. Since it is observed at 1,
The observer 1 looks as if the white point object is at the point P '.

If a color filter is added so that only a specific color passes through the transparent area, the point object can be colored. The same applies to the case of two points. Since the three-dimensional object is a set of point objects, if the number of points is increased steadily, light rays similar to the scattered light rays from the three-dimensional object can be reproduced in color.

In other words, the LCF 24 is the WCSO 22
Has the function of selecting and passing only the light rays from a specific part of the WCSO2.
It can be said that 2 makes it look like an object having a specific shape and color. It is the same as the previous ray reconstruction method in the sense that it reproduces light rays from an object, but that many of the rays that reproduce a specific point are rays coming from the same point of the scattering object, There is a significant difference in that only a three-dimensional object that actually exists or an image thereof is selectively observed. This difference causes the resolution of the observed image to be improved as much as the direct observation of an ordinary object.

In the example shown in FIG. 1, the points other than the points P 'and Q' of the WCSO 22 are cut off by the LCF 24 and cannot be seen.
It is observed as if there is a point object at P 'and Q'.

FIG. 2 is a block diagram of a three-dimensional image reproducing apparatus using an optical filter according to a second embodiment of the present invention. Here, a configuration example using a lens is shown.

In FIG. 2, reference numeral 31 denotes a white light source;
Is a white cloud-like scatterer, 33 is a lens, 34 is a pinhole array, 35 is a light weighting filter (liquid crystal, etc.), 3
6 is a generated image.

In this case, only the selected portion of the white cloud-like scatterer 34 is imaged by the lens 33, and the observer 1 observes the generated image 36. Pinhole array 3
By setting the position 4 and the position of the light weighting filter (liquid crystal etc.) 35 and the focal length of the lens 33, it is possible to make it difficult to observe behind the scenes at the position of the observer 1.

FIG. 3 is a block diagram of a three-dimensional image reproducing apparatus using an optical filter according to a third embodiment of the present invention. Here, the background at infinity can also be reproduced.

In FIG. 3, reference numeral 41 denotes a white light source;
Is a white solid cloud scatterer, 43 is an infinity generating lens, 44
Is a pinhole array, 45 is a ray weighting filter,
P ″ and Q ″ are three-dimensional reproduced images viewed by the observer 1.

Since the white cloud-like scatterers 22 and 32 shown in the first and second embodiments have a finite size, infinity cannot be reproduced in the first and second embodiments. In the third embodiment, if the parallel light is reproduced on the observer 1 side by using the infinity generation lens 43, the background at infinity can be reproduced.

The white solid cloud-like scatterers 22, 32, 4
Reference numeral 2 denotes a cloud-like translucent scatterer (may be a luminous body) in which white light can be seen to be scattered from any part inside the object. If it is too dense, you cannot see inside.

Light weighting filters 24, 35, 45
Is a film coated with dye, a color film,
In addition, liquid crystal shutters, which are spatially distributed and can control light transmittance and transmitted color, are collectively referred to.

The specific operation of the above embodiment will be described.

(1) Preparation of Filter by Recording Real Object The white cloud-like scatterers of the first and second embodiments are removed, and the object to be recorded is irradiated with a white light source.
The scattered light from the object passing through each pinhole reaches the ray weighting filter with each color.

As a result, on the ray weighting filter, all the holes become pinholes of the pinhole camera, and an image with a slightly different viewing angle appears, but this is also the trajectory of the ray. If it records like a positive film, it can act as a ray weighting filter. Since the resolution of the pinhole camera is not good, the resolution can be increased by inserting a microlens in the pinhole and forming a microlens array.

Since this image recording is the same as the integral photography or the light beam reproducing method, the method used therefor can be used here (it is not a feature itself). Needless to say, a pinhole array is required for reproduction. There is a method in which this image is captured by an electronic camera or a TV camera by some method and the liquid crystal shutter is used as a light beam weighting filter based on the captured image.

It is also possible to calculate a light beam passing through each pinhole and a light beam weighting filter by a computer, and to operate the film or the liquid crystal shutter based on the calculated light weight filter.

The product names to which the present invention can be applied include a three-dimensional display, a three-dimensional signboard, a wall-mounted show window, and the like.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0062]

As described above, according to the present invention, the following effects can be obtained.

(A) It is possible to reduce the image blur due to the spread of the light beam which cannot be avoided in the previous light beam reproduction method.

(B) By placing a lens between the observer and the pinhole array, the array can be out-of-focus and the array can be made invisible.

(C) By placing a lens between the white cloud-like light scattering object and the pinhole array, an image at infinity can be reproduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a three-dimensional image reproducing apparatus using an optical filter according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a three-dimensional image reproducing apparatus using an optical filter according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a three-dimensional image reproducing apparatus using an optical filter according to a third embodiment of the present invention.

FIG. 4 is a diagram illustrating the principle of stereoscopic vision.

FIG. 5 is a principle diagram of a light beam reproduction method.

FIG. 6 is a diagram illustrating an example of a three-dimensional image observation via a lens.

FIG. 7 is a diagram illustrating an example of a light beam reproduction method (simple object) via a lens.

FIG. 8 is a diagram illustrating an example of a light beam reproduction method (an ordinary object) via a lens.

[Explanation of symbols]

21, 31, 41 White illumination light source 22, 32, 42 White cloud-like scattering object (WCSO) 23, 34, 44 Pinhole array 24, 35, 45 Light weighting filter (LC
F) 25 Reconstructed ray group 33 Lens 36 Generated image 43 Lens at infinity

Claims (2)

[Claims] 1. A white illumination light source, (b) a white cloud light scattering object having a three-dimensionally uniform distribution, (c) a pinhole array, and (d) the white cloud light scattering. A color transmission spatial distribution filter having a function of spatially weighting the intensity and color of a group of light rays passing through the pinhole array out of the scattered light from the object, and (e) the white cloud-like light The scattering object is shaped rather than a uniform white cloud,
A three-dimensional image reproducing apparatus using an optical filter, characterized in that it looks like a three-dimensional object having a color. 2. A three-dimensional image reproducing apparatus using the optical filter according to claim 1, wherein one or more sheets are provided between the white cloud-like light scattering object and the color transmission space distribution filter or further behind the same. A three-dimensional image reproducing apparatus using an optical filter, wherein a lens is arranged.