JPH11202746A - Image data generation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a holographic stereogram capable of observing the change of the shape of two-dimensional or three-dimensional images corresponding to plural subjects by moving the observation view point. SOLUTION: In the case of three-dimensional images, a rendering camera 53 is linearly moved while keeping the distance df of the subject P and the rendering camera 53 fixed and plural images of different view points are generated by animations by CG first. The shape of the subject P to be photographed at this time is three-dimensionally changed by using a morphing processing. Then, a view point conversion processing for converting the position of the view point is executed to the image data of the generated plural images and thus, the image data of the images to be recorded in the holographic stereogram are generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for generating image data of an image to be recorded on a so-called holographic stereogram.

[0002]

2. Description of the Related Art A so-called holographic stereogram is based on a large number of images (parallax images) obtained by sequentially photographing an object from different observation points, and these are formed into a strip-shaped or holographic recording medium. It is created by sequentially recording as dot-shaped element holograms.

[0003] A schematic process of creating a holographic stereogram having parallax information only in the horizontal direction will be described with reference to FIG.

[0004] In FIG. 13, for example, in a process of creating a holographic stereogram having parallax information only in the horizontal direction, first, as shown in FIG. By sequentially photographing from the point, a parallax image sequence GD including a plurality of parallax images having parallax information in the horizontal direction is generated as illustrated in FIG.

Next, as shown in FIG. 13C, the image information processing apparatus 101 performs predetermined image information processing on the parallax image sequence data based on the parallax image sequence GD, Generate As shown in FIG. 13D, an exposure image ge is formed from the exposure image sequence data, and a laser beam LD is modulated by the exposure image ge. The modulated light passes through the optical system 102. As a result, the object light LO is formed into a strip-shaped object light and is irradiated onto the hologram recording medium 103. At the same time, the hologram recording medium 103 is also irradiated with the reference light LR separated from the laser light LD.

On the hologram recording medium 103,
As shown in FIG. 13E, interference fringes due to the object light LO and the reference light LR are sequentially recorded as changes in the refractive index so as to be continuous in the horizontal direction (the direction of the arrow H in the figure). That is, the object light LO recorded as a change in the refractive index
Further, interference fringes due to the reference light LR are formed on the hologram recording medium 103 as strip-shaped element holograms.
Thereby, a holographic stereogram having parallax information in the horizontal direction is obtained.

In this holographic stereogram, information of a plurality of images obtained by sequentially photographing from different observation points in the horizontal direction is sequentially arranged as a strip-shaped element hologram in the horizontal direction as described above. Since the recorded holographic stereogram is recorded with both eyes, the two-dimensional image shown in each eye is slightly different due to parallax between the left and right eyes,
As a result, the image is recognized as a three-dimensional image.

A parallax image sequence GD, which is an image serving as a source of the holographic stereogram, is a state in which the photographing direction of the photographing apparatus 100 at an angle of view θv is kept constant on the subject P side, as shown in FIG. Then, the photographing device 100
Are moved in parallel in the direction indicated by the arrow M in FIG.
The image is created by a shooting method for shooting the image, that is, a so-called straight track shooting method. That is, in this shooting method, the subject P and its background (the width lh of the holographic stereogram)
Is the angle of view θv of the photographing apparatus 100.
(Imaging range) Distance l from the position that falls within the position to the position that deviates
The photographing device 100 is moved in parallel by c, and a large number of images are photographed in the meantime.

[0009]

In the conventional holographic stereogram described above, a three-dimensional stereoscopic image corresponding to a single subject can be observed. 2D or 3
The thing which can observe the change of the shape of a two-dimensional image by moving the observation viewpoint has not been realized yet. That is, for example, when a holographic stereogram is observed from a certain position, for example, a two-dimensional or three-dimensional image corresponding to a certain subject can be observed, and when observed from another position, a two-dimensional or three-dimensional image corresponding to another subject can be obtained. There is no holographic stereogram from which an image can be observed.

Accordingly, the present invention has been proposed in view of the above-described circumstances, and is intended to be capable of observing a change in the shape of a two-dimensional or three-dimensional image corresponding to a plurality of subjects by moving its observation viewpoint. An object of the present invention is to propose an image data generation method capable of realizing a graphic stereogram.

[0011]

An image data generating method according to the present invention generates a plurality of images based on a plurality of different images by interpolating a shape change between the images, and converts the images into the plurality of images. The above-mentioned problem is solved by generating image data of an image to be recorded on the hologram recording medium by performing the following.

That is, for example, in the case of a three-dimensional image,
First, the imaging device is linearly moved while keeping the distance between the subject and the imaging device constant, and a plurality of images with different viewpoints are generated by animation using CG. At this time, the shape of the subject to be photographed is changed three-dimensionally using morphing processing. Next, a viewpoint conversion process for changing the position of the viewpoint is performed on the generated image data of the plurality of images, thereby generating image data of the image to be recorded on the holographic stereogram.

Here, when generating a plurality of images having different viewpoints, for example, every time a subject is photographed, a plurality of images having different viewpoints are generated by rendering by linearly moving the photographing device by a predetermined distance. I do.

When the viewpoint conversion process is performed, data is exchanged for each image sequence so that a reproduced image is formed near the hologram plane of the holographic stereogram. Generates image data of an image to be recorded on the holographic stereogram so that the image becomes a practical observation position.

In the image data generating method according to the present invention as described above, the reproduced image is localized near the hologram surface by the viewpoint conversion, and the observation viewpoint is set to a practical position. Further, since the shape of the subject changes in accordance with the movement of the imaging device, the change in the shape of the subject can be observed three-dimensionally by moving the observation point of the hologram.

By changing the data for each pixel row in the same way for an image obtained by the two-dimensional morphing process, it is possible to two-dimensionally observe the shape change of the object by moving the observation point of the hologram. .

Further, a holographic image is obtained by combining a two-dimensional image and a three-dimensional image so that, for example, the background can be observed three-dimensionally, and the two-dimensional object can observe a two-dimensional shape change by changing the viewpoint. Creation of stereograms is also possible.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, as one embodiment to which the image data generating method of the present invention is applied, a configuration example of a holographic stereogram creating system will be described.

This holographic stereogram creating system creates a so-called one-step holographic stereogram, in which a film-like holographic recording medium on which interference fringes between object light and reference light are recorded is used as it is as a holographic stereogram. System.

As shown in FIG. 1, the holographic stereogram creating system includes an image data generating unit 1 for generating image data of an exposure image to be recorded as an element hologram on the holographic stereogram. And a holographic stereogram printing apparatus 3 having an optical system for creating a holographic stereogram and the like.

The image data generating unit 1 applies the present invention to generate parallax image sequence data including a plurality of parallax images, and further records the data in a holographic stereogram based on the parallax image sequence data. Then, image data D1 of a plurality of exposure images corresponding to a plurality of element holograms is generated. The generation of the image data D1 by the image data generation unit 1 will be described later in detail.

Each time the image data generating unit 1 sends out image data D1 corresponding to one exposure image to the holographic stereogram printing device 3, the image data generation unit 1 generates one exposure image. A timing signal S1 indicating that the corresponding image data D1 has been transmitted is transmitted to the control computer 2.

The control computer 2 drives the holographic stereogram printing device 3 based on the timing signal S1 from the image data generator 1, and an exposure image based on the image data D1 generated by the image data generator 1. The holographic recording medium set in the holographic stereogram printing apparatus 3 is irradiated with the object light and the reference light, and the interference fringes of the object light and the reference light are sequentially recorded as strip-shaped element holograms.

At this time, the control computer 2 controls a shutter, a recording medium feeding mechanism, and the like provided in the holographic stereogram printing device 3 as described later. That is, the control computer 2 sends a control signal S2 to the holographic stereogram printing device 3 to control the opening and closing of the shutter, the feeding operation of the hologram recording medium by the recording medium feeding mechanism, and the like.

The holographic stereogram printing device 3 will be described in detail with reference to FIG.
FIG. 2A is a view of the entire optical system of the holographic stereogram printing apparatus 3 as viewed from above.
FIG. 2B is a view of a portion for the object light of the optical system of the holographic stereogram printing apparatus 3 as viewed from the lateral direction.

As shown in FIG. 2A, the holographic stereogram printing device 3 has a laser light source 31 for emitting laser light of a predetermined wavelength and a laser light L1 from the laser light source 31 disposed on the optical axis. The shutter 32 and the half mirror 33 are provided. The shutter 32 is
It is controlled by the control computer 2 and is closed when the hologram recording medium 30 is not exposed, and is opened when the hologram recording medium 30 is exposed. Also,
The half mirror 33 is for separating the laser light L2 that has passed through the shutter 32 into a laser light L3 for reference light and a laser light L4 for object light, and the laser light reflected by the half mirror 33. L3 is guided to the reference light optical system, and the laser light L4 transmitted through the half mirror 33.
Is guided to the optical system for the object light.

On the optical axis of the laser light L3 reflected by the half mirror 33, a cylindrical lens 3 for diffusing the laser light L3 is provided as an optical system for reference light.
4, a collimator lens 35 for converting the light diffused by the cylindrical lens 34 into parallel light, and a total reflection mirror 3 for reflecting the parallel light from the collimator lens 35.
6 are arranged in this order.

That is, the laser beam L3 reflected by the half mirror 33 is first transmitted to the cylindrical lens 3
4 is divergent light, and then the collimator lens 35
Is converted into parallel light. Thereafter, the light is reflected by the total reflection mirror 36 and enters the hologram recording medium 30 as reference light.

On the other hand, as shown in FIGS. 2A and 2B, the laser beam L4 transmitted through the half mirror 33 is transmitted through the half mirror 33 as an optical system for object light. A total reflection mirror 38 for reflecting the laser beam L4,
Laser light L4 combining convex lens and pinhole
, A collimator lens 40 for converting the diffused light from the spatial filter 39 into parallel light, and a display device for displaying an exposure image to be recorded based on the image data D1. 41,
A cylindrical lens 42 that condenses the light of the image for exposure from the display device 41 in a slit shape on the hologram recording medium 30 as object light is arranged in this order.

That is, the laser beam L4 transmitted through the half mirror 33 is reflected by the total reflection mirror 38, and is then converted into diffused light from a point light source by the spatial filter 39. Next, the diffused light is converted into parallel light by the collimator lens 40, and thereafter, enters the display device 41. Here, the display device 41 is a transmissive image display device including, for example, a liquid crystal panel, and displays an exposure image based on the image data D1 sent from the image data generation unit 1. Therefore, the parallel light from the collimator lens 40 is modulated according to the exposure image displayed on the display device 41. The modulated light corresponding to the exposure image is incident on the cylindrical lens 42.

The cylindrical lens 42 converges light modulated according to the exposure image in the horizontal direction (parallax direction) by transmitting through the display device 41, and uses the converged light as object light as the hologram recording medium 30. Incident on. Thus, the holographic stereogram printing device 3
Then, the light modulated according to the exposure image by the display device 41, that is, the projection light of the exposure image, enters the hologram recording medium 30 as strip-shaped object light.

Here, the reference light and the object light are such that the reference light is incident on one surface of the hologram recording medium 30 and the object light is incident on the other surface of the hologram recording medium 30. That is, the reference light is made incident on one surface of the hologram recording medium 30 at a predetermined incident angle, and the object light is emitted on the other surface of the hologram recording medium 30 along the optical axis with respect to the hologram recording medium 30. Are made substantially perpendicular. As a result, the reference light and the object light interfere with each other on the hologram recording medium 30, and the interference fringes generated by the interference form the hologram recording medium 3.
Recorded as a change in refractive index at 0. The details of the hologram recording medium 30 used in the present embodiment will be described later.

The holographic stereogram printing apparatus 3 includes a recording medium feeding mechanism 43 that can intermittently feed the hologram recording medium 30 under the control of the control computer 2. The recording medium feeding mechanism 43 is configured to output one exposure image based on the image data D1 generated by the image data generating unit 1 to the hologram recording medium 30 set in a predetermined state in the recording medium feeding mechanism 43. Each time it is recorded as one element hologram,
Based on a control signal S2 from the control computer 2,
The hologram recording medium is intermittently fed by one element hologram. Thereby, the exposure image based on the image data D1 generated by the image data generation unit 1 is sequentially recorded as an element hologram on the hologram recording medium 30 so as to be continuous in the lateral direction (parallax direction). Details of the recording medium feeding mechanism 43 will be described later.

In the holographic stereogram printing apparatus 3, the optical path length of the reference light from the reflection by the half mirror 33 to the incidence on the hologram recording medium 30, and the transmission of the display light through the half mirror 33 to the display device 41 are described. It is preferable that the optical path length of the object light from when the light passes through the hologram recording medium 30 be substantially the same. Thereby, the coherence between the reference light and the object light increases, and the image quality of the holographic stereogram improves.

In the holographic stereogram printing apparatus 3, a diffusion plate may be provided on the optical path of the object light optical system in order to improve the holographic stereogram image quality. By disposing the diffuser in this way, noise included in the object light is dispersed,
Further, the light intensity distribution of the object light incident on the hologram recording medium becomes more uniform, and the image quality of the created holographic stereogram is improved.

However, when disposing the diffusion plate in this manner, a mask having a strip-shaped opening corresponding to the shape of the element hologram may be disposed between the diffusion plate and the hologram recording medium 30. preferable. By disposing the mask in this way, of the light diffused by the diffusion plate,
An extra portion is blocked by the mask, so that a higher-quality holographic stereogram can be created.

Further, in the holographic stereogram printing apparatus 3, in order to give the holographic stereogram a vertical viewing angle, the light is vertically diffused on the optical path of the object light optical system. A two-dimensional diffusion plate may be provided. By arranging the one-dimensional diffusing plate in this way, light is diffused in the vertical direction, that is, in the long axis direction of the element hologram to be created, whereby the created holographic stereogram has a vertical viewing angle. It will be.

However, when such a one-dimensional diffusion plate is provided, it is preferable to provide a louver film having a fine grid-like lattice between the hologram recording medium 30 and the one-dimensional diffusion plate. By disposing the louver film in this way, it is possible to prevent the reference light transmitted through the hologram recording medium 30 from being reflected by the one-dimensional diffusion plate and entering the hologram recording medium 30 again.

Next, the operation of the holographic stereogram creating system will be described.

When creating a holographic stereogram, the image data generator 1 displays the image data D on the display device 41 of the holographic stereogram printing device 3.
1 is transmitted, and an image for exposure based on the image data D1 is displayed on the display device 41. At this time, the image data generation unit 1 sends to the control computer 2 a timing signal S1 indicating that the image data D1 has been sent to the display device 41 of the holographic stereogram printing device 3.

Then, the control computer 2 having received the timing signal S 1 sends the control signal S 2 to the shutter 32.
Is transmitted, the shutter 32 is opened for a predetermined time, and the hologram recording medium 30 is exposed. At this time, the laser light L emitted from the laser light source 31 and transmitted through the shutter 32
2, the laser beam L3 reflected by the half mirror 33 is incident on the hologram recording medium 30 via the reference light optical system. The laser beam L4 transmitted through the half mirror 33 is incident on the optical system for object light, and is incident on the hologram recording medium 30 as object light based on the exposure image displayed on the display device 41. This allows
An interference fringe between the object light and the reference light based on the exposure image displayed on the display device 41 is recorded on the hologram recording medium 30 as a strip-shaped element hologram.

Then, 1 is written to the hologram recording medium 30.
When the recording of the image is completed, the control computer 2 sends a control signal S2 to the recording medium feeding mechanism 43, and
The hologram recording medium 30 is fed by one element hologram.

The above operation is repeated by sequentially changing the exposure images to be displayed on the display device 41 in the order of the parallax images in the parallax image sequence. Thereby, the hologram recording medium 30 includes:
Strip-shaped element holograms are sequentially recorded.

When the element holograms are sequentially recorded in this manner, when the hologram recording medium 30 is fed by the recording medium feeding mechanism 43, the hologram recording medium 30 slightly vibrates. Therefore, each time the hologram recording medium 30 is fed, the vibration is settled, and after the vibration is settled, the element hologram is recorded.

As described above, in this holographic stereogram creating system, the hologram recording medium 3
Each time recording to 0 is performed, the shutter 32 is opened, and a plurality of exposure images based on the image data D1 generated by the image data generation unit 1 are sequentially displayed on the display device 41. The interference fringes between the object light and the reference light are sequentially recorded on the hologram recording medium 30 as strip-shaped element holograms. At this time, since the hologram recording medium 30 is sent by one element hologram for each exposure, each element hologram is continuously arranged in the horizontal direction. As a result, a plurality of images including lateral parallax information are recorded on the hologram recording medium 30 as a plurality of laterally continuous element holograms, and a holographic stereogram having lateral parallax is obtained.

Next, in the holographic stereogram creating system having the above-described configuration, a change in the two-dimensional or three-dimensional shape corresponding to a plurality of subjects can be observed by moving the observation viewpoint. A specific example for realizing the above, that is, details of the image data generating operation in the image data generating unit 1 of FIG. 1 will be described below.

First, as a first embodiment of the present invention,
An image data generation method for realizing a holographic stereogram capable of observing a three-dimensional shape change corresponding to a plurality of subjects will be described.

The image data generator 1 in the system of the first embodiment can generate a plurality of images serving as a source of a holographic stereogram, that is, a parallax image sequence by, for example, so-called CG (computer graphic). Has a computer.

At the time of generating a parallax image sequence by CG,
For example, as shown in FIG. 3, a position of a virtual photographing device (hereinafter, referred to as a rendering camera 53) is fixed in a state where a virtual subject P is fixed in a CG space and a virtual photographing distance df is maintained. The viewpoint position is moved in parallel and linearly at regular intervals with respect to the subject P, and the optical axis of the virtual lens PL and the rendering screen surface are maintained at a right angle for each of the equally spaced shooting positions. Lens PL
Is performed in such a manner that the object P is moved in the horizontal direction, and the focused subject P is positioned at the center of the rendering screen to perform rendering. Such a shooting method,
It is called a re-centering photographing method, and is an effective photographing method for eliminating so-called keystone distortion.

That is, when a parallax image sequence is generated by the system using the CG, a virtual subject P is fixed, and a single parallax image (C
Each time a projection image of the subject P in the G space is generated, the rendering camera 53 is linearly moved by a predetermined pitch in a fixed direction indicated by an arrow M in FIG. Generate In this case,
The rendering camera has a distance lb from the position where the virtual subject P and its background (the range 52 corresponding to the width le of the holographic stereogram) fall within the angle of view θc (imaging range) of the rendering camera 53. 53 is translated, during which a number of images are generated.

In the system according to the first embodiment, in order to realize a holographic stereogram capable of observing a three-dimensional shape change corresponding to a plurality of virtual subjects P, the CG is used. So-called 3D
By the morphing process, the three-dimensional shape of the virtual subject P itself is deformed by the CG every time the rendering camera 53 is moved. This makes it possible to obtain a parallax image sequence having a parallax in the horizontal direction and having a three-dimensional shape change of the subject itself. Therefore, if the element holograms generated from the parallax image sequence obtained by changing the shape of the subject P itself three-dimensionally are recorded on the hologram recording medium 30 as described above, 3Ds corresponding to a plurality of subjects can be obtained.
A holographic stereogram capable of observing a dimensional change in shape can be realized.

In the first embodiment, an example in which the subject P itself is three-dimensionally changed in shape by CG to generate a parallax image sequence is described. However, as a second embodiment,
For example, it is also possible to create a holographic stereogram from which a three-dimensional shape change can be observed in the same manner as described above, from an actual image photographed using a CCD (solid-state imaging device) camera or the like.

In the system according to the second embodiment, the recentering photographing method shown in FIG. 3 is applied to an actual photographing system, and a parallax image sequence is photographed by actual photographing using this photographing system.

In the system according to the second embodiment, when creating a holographic stereogram capable of observing a three-dimensional change in shape of, for example, two real maps A and B, first, for example, FIG. As shown in (c) and (c), two sets of parallax image sequences GA and GB are generated by photographing two subjects A and B, respectively, by actual photography.

Next, the two sets of parallax image sequences GA and GB captured by the CCD camera are subjected to a morphing process between the parallax images at the same viewpoint position to obtain a morphing process as shown in FIG. As shown, an intermediate image sequence is generated, and this intermediate image sequence is used as a new parallax image sequence GC. That is, the morphing process is, for example, a process of gradually or instantaneously transforming the shape of one original image into the shape of the other original image in two original images, or a process of combining intermediate images of the original images. is there. Therefore, in the morphing process in the present embodiment, the two sets of parallax image sequences AG and B are used as the two original images.
Generating an intermediate image from the respective parallax images corresponding to G,
A parallax image sequence C composed of the intermediate images is obtained.

In the system according to the second embodiment, a holographic stereogram is created using these parallax image sequences GA, GB, and GC. Here, for example, the created holographic stereogram is observed. When the holographic stereogram is observed from one side in the horizontal direction, for example, an image corresponding to the subject A itself can be observed, and when observed from the opposite side, for example, an image corresponding to the subject B itself can be observed. An image whose shape gradually changes from an image corresponding to the subject A to an image corresponding to the subject B (or from the image corresponding to the subject B to the subject A) between the one side and the opposite side. (An image whose shape gradually changes to an image corresponding to the image) is desired to be observed by morphing as shown in FIG. Using the degree of mixing, performs morphing processing for all the parallax images while changing the degree of mixing of the parallax image string GA and GB, and generates a new parallax image string C. Of course, such a method can also be used when generating a parallax image sequence by CG as in the first embodiment.

Note that the parallax image sequence in the first and second embodiments described above is obtained by moving the rendering camera or CCD camera by a predetermined pitch as shown in FIG. In other words, it is generated by photographing, for example, about 500 images.

However, it takes time to photograph as many as 500 images when generating a parallax image sequence by actual photography as in the second embodiment. Therefore, in this case, when generating a parallax image sequence for one subject, for example, the same subject is photographed from different viewpoints to generate several parallax images, and the viewpoint direction ( Lateral direction)
Is subjected to a morphing process to generate an interpolated image of the parallax image in the parallax direction. That is, in the morphing process in the interpolation process of the parallax image in the parallax direction, parallax images obtained by photographing the same subject from different viewpoints are used as two original images before the morphing process, and the morphing process is performed from these parallax images. The intermediate image is used as the interpolation image. Accordingly, it is possible to generate a parallax image sequence including a large number of parallax images such as the above-described 500 parallax images from a small number of parallax images,
It is possible to reduce the number of shot parallax images and the shooting time.

Incidentally, in the holographic stereogram, the positional relationship between the viewpoint of the photographing device (camera) and the subject at the time of photographing is held even for the reproduced image of the created holographic stereogram. For this reason, when a holographic stereogram is created using image data of a parallax image sequence obtained by photographing a subject as it is, as shown in FIG. 63
Than the distance dv corresponding to the distance from the center of the subject at the time of photographing to the viewpoint of the photographing device (that is, the photographing distance).
An image will be formed in the back by the amount of the image. Further, in particular, in a white reproduction holographic stereogram reproduced by white light, the reproduced image 60 has such a property that the blur becomes smaller as it is localized near the hologram surface 63. When the reproduced image 60 is formed farther away from the hologram surface 63 than the hologram surface 63 as shown in FIG. 5, for example, the reproduced image 60 is blurred.

Therefore, in such a holographic stereogram 62, in order to observe the reproduced image 60 in a good state without distortion or blur, the distance dv between the reproduced image 60 and the viewpoint 61 is determined by changing the distance dv at the time of photographing. As long as the observation is not performed so as to coincide with the shooting distance from the center of the imaging device to the viewpoint of the imaging apparatus, that is, unless the viewpoint 61 is viewed on the hologram plane 63, the reproduction image 6
Distortion and blurring occur at 0. However, if such a use state is actually applied, the eyes must be pressed against the hologram surface, which is not practical.

Therefore, in the first and second embodiments of the present invention, in order to solve this problem, when generating image data from a parallax image sequence, as shown in FIG. A viewpoint conversion process is performed so that the holographic stereogram 62 is localized near the hologram surface 63 of the holographic stereogram 62.

That is, the image data generation unit 1 of the system according to the embodiment of the present invention includes means for performing a viewpoint conversion process for reconstructing image data of an exposure image sequence from image data of a parallax image sequence. In the holographic stereogram printing device 3, each image for exposure corresponding to the image data subjected to the viewpoint conversion process from the image data generating unit 1 is sequentially displayed on the display device 41, and the holographic stereogram printing device 3 displays the images for exposure. An interference fringe between the image-modulated object light and the reference light is recorded on the hologram recording medium 30 as each element hologram. As a result, the holographic stereogram 62 is such that, as shown in FIG. 6, the reproduced image 64 is localized near the hologram surface 63, so that the observer does not look at the hologram surface 63 and observes it. In both cases, it is possible to observe a clear reproduced image 64 without distortion or blur.

Here, the viewpoint conversion process is an image process of reconstructing a new image (exposure image) by replacing the parallax information of a plurality of parallax images constituting the parallax image sequence. When the parallax direction is only the horizontal direction as in the present embodiment, the image for exposure is subjected to a viewpoint conversion process in which the order of the slit-shaped pixel columns in the vertical direction of the parallax image is changed. Rebuild. More specifically, the parallax image includes, for example, 640 pixels in the vertical direction and 480 pixels in the horizontal direction (parallax direction), and the image for exposure also includes, for example, 640 pixels in the vertical direction and horizontal direction (parallax direction).
Assuming that the image is configured with a resolution and an image size of 480 pixels, in the viewpoint conversion processing, the minimum unit for replacing the parallax information of the parallax image is 6 in the vertical direction.
One column of slit-shaped image information consisting of 40 pixels and one pixel in the horizontal direction (parallax direction) is extracted from the parallax image, and the order of each slit-shaped image information is changed to combine 640 pixels in the vertical direction and horizontal (parallax direction). (Direction) A process of reconstructing an image of 480 pixels as the exposure image is performed.

Hereinafter, the above viewpoint conversion processing will be described in detail with reference to FIGS. 7 and 8. 7 and 8 show n exposure images g21 and g2 from a parallax image sequence GD composed of m pieces of parallax images g11, g12,...
It is a figure for explaining the principle of viewpoint conversion processing which reconstructs exposure image sequence GE consisting of 2, ..., g2n.

FIG. 7 shows the exposure points ep (ep1,..., Ep) on the hologram surface 63 of the holographic stereogram 62 having a length of le in the parallax direction (lateral direction).
n), exposure images g21, g22,..., g2n for exposing and recording each element hologram (the long axis direction of the strip-shaped element hologram is perpendicular to the paper surface), and a parallax image sequence GD Of each parallax image g11, g12, ..., g
It is a figure for explaining a positional relationship with 1m.

In FIG. 7, le indicates the length of the holographic stereogram 62 in the parallax direction (lateral direction), and Δle indicates the respective exposure points ep on the hologram surface 63 of the holographic stereogram 62. Is the hologram exposure angle (the condensing angle θ of the cylindrical lens 42 in FIG. 2).
s). In the figure, lb represents m parallax images g11,
.., g1m correspond to the actual photographing width (moving distance of the photographing device) when generating the parallax image sequence GD, and Δlb in the figure represents the photographing width at the time of photographing each parallax image (the photographing device). In the drawing, Is is the exposure image screen width (the display screen width of the display device 41), and dv is the distance from the hologram surface 63 to the observer's viewpoint when observing the holographic stereogram 62 (moving pitch). Viewpoint distance)
In the figure, df corresponds to the distance from the center of the subject at the time of shooting to the viewpoint of the shooting device (camera) (ie, the shooting distance of the parallax image). Although Δlb and Δle are not always equal, the viewpoint distance dv is equal to the shooting distance df of the parallax image.

In FIG. 7, for convenience of explanation, ep1, ep2 and ep of the respective exposure points ep1,.
Only three points of pn are shown. Of course, these exposure points e
The number n of p differs depending on the length le of the holographic stereogram 62 in the parallax direction and the exposure pitch Δle (the pitch of the element hologram) which is one parameter indicating the resolution of the hologram. Δle is an equal pitch of, for example, 0.2 mm, and the length le of the holographic stereogram 62 in the parallax direction.
Is 100 mm, for example, the number of exposure points ep is n = 5
It is about 00. Further, the exposure pitch Δl of the exposure point ep
e is equal to the pitch of each exposure image g21, g22,..., g2n, and the holographic stereogram 62
Is related to the length le of the parallax direction as follows: le = n × Δle (1)

FIG. 8 shows one exposure image (eg, g21) out of the plurality of exposure images g21, g22,..., G2n shown in FIG.
1 shows a state in which elementary holograms are reconstructed from a parallax image (for example, g11) by a viewpoint conversion process and an element hologram is exposed on an exposure point ep1 with the exposure image g21.
In the figure, DV is a holographic stereogram 62.
Shows a virtual plane (hereinafter, referred to as a mapping plane) corresponding to a position separated from the hologram plane 63 by a parallax distance dv. In the drawing, DD denotes a shooting distance df (=
dv) are separated by mp (mp11, mp12,..., mp) in the figure.
1k) indicates the sampling points of the exposure image g21 on the mapping plane DV, and op (op11, op12,.
···, opij, op21, ...) is the screen surface D
Each sampling point of the parallax images g11, g21,... On D is shown. Here, for example, assuming that the image for exposure is an image having 640 pixels in the vertical direction and 480 pixels in the horizontal direction, the sampling number (pixel number) in the parallax direction of the exposure image is 480, and thus, k is 480. . If the parallax image is an image having 640 pixels in the vertical direction and 480 pixels in the horizontal direction, the sampling number (the number of pixels) in the parallax direction of the parallax image is 480, and thus j = 480.

In FIG. 7 and FIG. 8 described above, the viewpoint conversion process is, for example, a process in which the image information at each of the sampling points mp11, mp12,. Which parallax information of the parallax images g11, g21,... In the column GD (sampling points op11, op12,.
.., Opij, op21,...) To perform image reconstruction.

That is, for example, the exposure point ep1 corresponding to the exposure image g21 and the sampling points mp11, mp1
2,... Mp1k and a straight line (a line shown by a thick line in FIG. 8) extending to the screen surface DD is referred to as a mapping line ml. Parallax image g1
One of the sampling points op1, g1,.
, Op1j, op21,..., The mapping line ml is the screen surface D
The processing is such that the closest parallax image and its sampling point op are selected for the points that intersect D.

This processing will be described in more detail by taking the sampling point mp11 as an example. In this mapping, a mapping line ml passing through the sampling point mp11 is used.
The point closest to the intersection between the screen and the screen surface DD is shown in FIG.
And the sampling point op1j of the parallax image g11 is selected. Other sampling points mp12, mp13, ..., mp1
By performing the same processing for k, one new exposure image g21 can be reconstructed. Further, by performing the same processing for the other exposure points ep2, ep3,..., And epn, the exposure images g22, g23,. In the example of FIG. 8, for convenience of explanation, each sampling point op11, op12,... Of the parallax image g11.
, Opij and each sampling point m of the image for exposure g21
The example in which p11, mp12,..., mp1k are present on the mapping line ml is described. Each sampling point of the parallax image does not always exist.

In the case where the parallax direction is only the horizontal direction as in the present embodiment,
A parallax image having a shooting viewpoint closest to the point where the mapping line ml intersects the mapping surface DV is selected, and a vertical line at a position where a mapping line connecting the shooting viewpoint and the exposure point intersects the screen surface DD. This is a process of selecting a slit-like pixel row in the direction. More specifically, the parallax image includes, for example, 640 pixels in the vertical direction and 480 pixels in the horizontal direction (parallax direction), and the image for exposure also includes, for example, 640 pixels in the vertical direction and 4 pixels in the horizontal direction (parallax direction).
Assuming that the image is configured with a resolution and an image size of 80 pixels, in the mapping, 640 pixels in the vertical direction and 1 in the horizontal direction (parallax direction) of the parallax image located at the point where the new mapping line intersects the screen surface DD.
The process is such that one line of pixels is selected.

Further, as described above, instead of selecting the sampling points op closest to the point where the mapping line ml intersects the screen plane DD, the sampling points op are generated by interpolation from a plurality of sampling points op near the mapping line ml. It is also possible to use the obtained image information as a calculation result by mapping. of course,
Instead of selecting one line closest to the point where the mapping line ml intersects the screen surface DD,
Line image information generated by interpolation from a plurality of lines near the mapping line ml can be used as a calculation result by mapping.

The exposure image sequence GE (g21, g22,..., G) reconstructed by the viewpoint conversion process as described above
2n) is recorded as an elementary hologram on the hologram recording medium 30 as described above to generate a holographic stereogram, and as shown in FIG. As a result, the reproduced image 64 moves toward the observer from the surface by the distance dv, and accordingly, the reproduced image 64 also moves toward the observer by the distance dv. As a result, the reproduced image 64 is localized near the hologram surface 63. If the observer observes the holographic stereogram 62 at a distance dv,
It is possible to observe a clear reproduced image 64 with no spatial distortion and little blur.

In the first and second embodiments described above, the image data generating method for realizing a holographic stereogram capable of observing a three-dimensional shape change corresponding to a plurality of subjects has been described. However, in the following third embodiment, a description will be given of an image data generating method for realizing a holographic stereogram capable of observing a two-dimensional shape change corresponding to a plurality of subjects. In the following description, a holographic stereogram capable of observing a two-dimensional shape change is defined as a holographic stereogram.
D Morphing Hologram (2D Morphing)
(Hologram).

In the third embodiment, first,
A plurality of (two or more) two-dimensional still images serving as original images of the 2D morphing hologram are captured by, for example, a digital still camera. This photographed image is called a key image. Then, an intermediate image is generated from these key images using a morphing process. At this time, the number of morphing images generated including the key image is made equal to the number of morphing samples in the time axis direction.

The image data generating method according to the third embodiment will be described with reference to FIG. In FIG. 9, the number of morphing samples is 3 for simplicity.

FIG. 9A shows key image sequences GK1 and GK2 and an intermediate image sequence GM generated by morphing processing using these key image sequences GK1 and GK2. In the following description, these key image sequences G
K1, GK2 and the intermediate image sequence GM are collectively called a morphing image sequence.

Here, in order to create a 2D morphing hologram, it is necessary to generate an exposure image from these morphing image sequences.

In the third embodiment, an exposure image for realizing a 2D morphing hologram is shown in FIG.
(B) It is generated by image conversion as shown by the arrow in the middle. That is, the image conversion is performed as shown in FIG.
As shown in FIG. 9B, pixel information at the same position is extracted from each of the key image rows GK1, GK2 and the intermediate image row GM, and as shown in FIG. This is realized by reconstructing the image for use. In these newly reconstructed exposure images, a temporal change in morphing at a certain position of the original image in the horizontal direction can be observed.

In the example shown in FIG. 9, the number of morphing samples is set to 3 for simplicity of explanation. It is set to about 500.

A more specific example will be described with reference to an example of parameter setting for image generation. For example, consider a case where a 2D morphing hologram is created with a width of 60 mm, a height of 80 mm, and a morphing sampling number of 480. In the 2D morphing image sequence, assuming that the morphing sampling number and the horizontal sampling number of the image are the same, 480 image sequences having a width of 480 pixels and a height of 640 pixels are generated by the morphing process. Furthermore, the element hologram width is 0.2 m
If m, the number of element holograms of the holographic stereogram to be created is 60.0 / 0.2 = 300. Therefore, it is sufficient to generate an exposure image to be exposed at the position of the element hologram, so that 300 new exposure images are generated from the 480 morphing image sequence.

In the third embodiment, as shown in FIG. 10, an exposure image is reconstructed from an original image of, for example, 640 pixels in the vertical direction and 480 pixels in the horizontal direction. The holographic stereogram 6
By exposing 2 (hologram recording medium),
A 2D morphing hologram in which a two-dimensional shape change can be observed when the eye is moved in the lateral direction indicated by an arrow MI in the drawing can be created.

In the third embodiment, an example in which a two-dimensional still image is photographed by a digital still camera has been described. However, a two-dimensional still image generated by CG may be used.

In each of the above-described embodiments, an example is described in which parallax is provided only in the horizontal direction. However, the present invention can also be applied to a device having parallax in the vertical direction. It is possible to apply the present invention to those having.

Next, the hologram recording medium 30 will be specifically described.

The hologram recording medium 30 has the structure shown in FIG.
As shown in (a), the tape-shaped film base material 83
A photopolymer layer 82 made of a photopolymerizable photopolymer is formed thereon.
Is formed, and a so-called coating-type film-shaped recording medium in which a cover sheet layer 81 is formed on the photopolymer layer 82 is used. Of course, any other suitable photosensitive film having a different layer configuration may be used as the hologram recording medium 30.

FIG. 11B to FIG. 11D show
FIG. 4 is a diagram illustrating the principle of recording element holograms on the hologram recording medium 30. In the initial state of the hologram recording medium 30, as shown in FIG. 11B, the photopolymerizable photopolymer constituting the photopolymer layer 82 is in a state where the monomers M are uniformly dispersed in the matrix polymer. It is in.

The photopolymerizable photopolymer is 10 mJ / cm
^By irradiating the laser beam LA having a power of ^{2 to} 400 mJ / cm ² , as shown in FIG. 11C, the monomer MO uniformly dispersed in the matrix polymer in the exposed portion is polymerized to form a polymer. It will be in the state of having done. In the photopolymerizable photopolymer, since the concentration of the monomer MO becomes non-uniform due to movement from the periphery of the monomer MO due to polymerization, the refractive index is modulated between the exposed portion and the unexposed portion.

Thereafter, the photopolymerizable photopolymer will be described with reference to FIG.
As shown in (d), the entire surface is irradiated with ultraviolet light or visible light LB having a power of about 1000 mJ / cm ² , thereby completing the polymerization of the monomer MO in the matrix polymer. The hologram recording medium 30 is such that the photopolymerizable photopolymer constituting the photopolymer layer 82 is
Since the refractive index changes according to the incident laser light LA, the interference fringes generated by the interference between the object light and the reference light are recorded as the change in the refractive index as described above.

In the holographic stereogram printing apparatus 3, by using the above-mentioned coating type film-shaped recording medium in which the photopolymer layer 82 is formed by the above-mentioned photopolymerizable photopolymer as the hologram recording medium 30,
After exposing and recording the element hologram, a step of performing a special development process on the hologram recording medium 30 is not required. Accordingly, the holographic stereogram printing device 3 is simplified in its configuration by eliminating the need for a developing device and the like, and can quickly create a holographic stereogram.

Next, details of the holographic stereogram printing device 3 will be described with reference to FIG.

In FIG. 12, the recording medium feeding mechanism 43 of the holographic stereogram printing device 3
A supply roller 97 rotatably provided in the film cartridge 96 and having the hologram recording medium 30 wound thereon; a driving roller 90 for intermittently running the hologram recording medium 30 unwound from the film cartridge 96; The hologram recording medium 30 includes a torsion spring (not shown) that applies a predetermined running tension to the hologram recording medium 30.

The recording medium feeding mechanism 43 includes a supply roller 97.
And the driving roller 90, the hologram recording medium 30
Are supported so as to be perpendicular to the optical axes of the object light optical system and the reference light optical system, respectively. In addition, the recording medium feeding mechanism 43 is intermittently driven to rotate by a driving stepping motor (not shown) of the driving roller 90. The stepping motor has a control output S2 sent from the control computer 2.
As a result, each time one element hologram is exposed, it is driven to rotate by a predetermined angle. Accordingly, the hologram recording medium 30 is intermittently driven by the stepping motor via the driving roller 90 which is driven to rotate by the stepping motor for each exposure and recording of one element hologram, thereby providing the object light LO.
The element holograms due to the interference fringes between the light and the reference light LR are sequentially exposed and recorded in the parallax direction.

As shown in FIG. 12, the holographic stereogram printing device 3 has a recording medium feeding mechanism 4.
3, an ultraviolet irradiation device 91 is provided along the traveling path of the hologram recording medium 30. The ultraviolet irradiating device 91 is a hologram recording medium 3 on which an element hologram is exposed and recorded by interference fringes between object light and reference light.
By irradiating ultraviolet light LB with a power of about 1000 mJ / cm ² to 0, polymerization of the monomer MO in the matrix polymer of the photopolymer layer 82 is completed as described above.

The holographic stereogram printing apparatus 3 includes a heat roller 92 provided with a heater 93 inside the holographic recording medium 30 along the traveling path of the hologram recording medium 30 at a stage subsequent to the ultraviolet irradiation apparatus 91. A pair of discharge feed rollers 94 and a cutter mechanism 95 are sequentially arranged. The heat roller 92 travels with the hologram recording medium 30 being wound around the outer peripheral portion thereof at a winding angle of about half a circumference. Further, the heat roller 92 is connected to the heater 9.
By keeping the temperature at about 120 degrees Celsius by 3, the hologram recording medium 30 is heated to increase the refractive index modulation degree of the photopolymer layer 82.

The discharge feed roller 94 is driven to rotate in synchronization with the drive roller 90 of the recording medium feed mechanism 43 by the control output S2 sent from the control computer 2. The discharge feed roller 94 intermittently feeds the hologram recording medium 30 every time one element hologram is exposed and recorded. Therefore, the hologram recording medium 30 is
Uniform heating is performed by running between the discharge feed roller 94 and the drive roller 90 in a state of being tightly contacted with the outer peripheral portion of the heat roller 92 without bending.

The cutter mechanism 95 is driven by a control output S2 sent from the control computer 2, and moves the traveling hologram recording medium 30 to a fixed length, that is, all the element holograms are stored in the hologram recording medium 30 in the parallax direction. A holographic stereogram is formed by arranging the holographic stereograms arranged side by side and cutting the recording portion in a state of being discharged to the outside.

The recording medium feeding mechanism 43 is
The rollers are not limited to the supply roller 97, the drive roller 90, and the discharge feed roller 94. As the recording medium feeding mechanism 43, for example, a feeding mechanism composed of a sprocket having perforations formed on a film body at a constant pitch and having feeding claws engaged with the perforations, a lever intermittently swinging, A conventionally well-known film body feeding mechanism including a feeding mechanism may be appropriately employed.

[0101]

As described above in detail, according to the image data generating method of the present invention, based on a plurality of different multi-dimensional images, a plurality of multi-dimensional interpolations of shape changes between the images are performed. By generating image data of an image to be recorded on the hologram recording medium by generating image data of the plurality of multidimensional images and generating image data of an image to be recorded on the hologram recording medium, for example, a two-dimensional or three-dimensional image It is possible to realize a holographic stereogram in which a change in shape can be observed by moving the observation viewpoint. That is, in the present invention, a holographic stereogram that can be subjected to image conversion for hologram recording on a parallax image that has been subjected to morphing processing and combined with an image obtained by CG or actual shooting to observe a change in shape is created. Is possible.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a holographic stereogram creating system.

FIG. 2 is a diagram illustrating a configuration example of an optical system of a holographic stereogram printing apparatus.

FIG. 3 is a diagram illustrating an example of a system for generating a parallax image sequence by a re-centering photographing method.

FIG. 4 is a diagram illustrating an example of generating a parallax image sequence for 3D morphing.

FIG. 5 is a diagram illustrating a state in which a reproduced image from a holographic stereogram created without performing a viewpoint conversion process is observed.

FIG. 6 is a diagram illustrating a state in which a reproduced image from a holographic stereogram created after performing a viewpoint conversion process is observed.

FIG. 7 is a diagram used for describing viewpoint conversion processing.

FIG. 8 is a partially enlarged view used for describing a viewpoint conversion process.

FIG. 9 is a diagram used to explain the relationship between a 2D morphing image for a 2D morphing hologram and an image for exposure.

FIG. 10 is a diagram showing how a holographic stereogram is generated by a 2D morphing hologram.

FIG. 11 is a diagram used to describe a hologram recording medium.

FIG. 12 is a diagram used to describe a specific configuration of a holographic stereogram printing apparatus.

FIG. 13 is a diagram for explaining a holographic stereogram creating process.

FIG. 14 is a diagram illustrating an example of a system for generating a parallax image sequence by a straight track photographing method.

[Explanation of symbols]

1 image data generation unit, 2 control computer,
3 holographic stereogram printing device,
31 laser light source, 32 shutter, 33 half mirror, 34, 42 cylindrical lens, 35,
40 collimator lens 35, 36, 38 total reflection mirror, 39 spatial filter, 41 display device, 30 hologram recording medium, 43 recording medium feeding mechanism

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hikaru Ishimoto 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (5)

[Claims] 1. A method for generating a plurality of images based on a plurality of different images by interpolating a shape change between the images, performing image conversion on the plurality of images, and storing image data of an image to be recorded on a hologram recording medium. Generating an image data. 2. A method for generating a plurality of two-dimensional images by two-dimensionally interpolating a shape change between the two-dimensional images based on a plurality of different two-dimensional images, and performing image conversion on the plurality of two-dimensional images. 2. The image data generating method according to claim 1, further comprising generating image data of an image to be recorded on the hologram recording medium. 3. A method for generating a plurality of three-dimensional images by three-dimensionally interpolating a shape change between the three-dimensional images based on a plurality of different three-dimensional images, and two-dimensionally projecting the plurality of three-dimensional images. 2. The image data generating method according to claim 1, wherein image conversion is performed on the image to generate image data of the image to be recorded on the hologram recording medium. 4. The plurality of different images are subjected to an interpolation process for interpolating a shape change between different parallax images at the same viewpoint position on all of the parallax images based on a plurality of sets of parallax image sequences. 2. The image data generating method according to claim 1, further comprising an image generated by the image processing. 5. The image data generation method according to claim 3, wherein an interpolation process for interpolating a change in shape is performed on the parallax direction of the parallax image sequence.