JP3390221B2 - Holographic stereogram - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to holographic stereograms. A holographic stereogram is one of the currently widely studied means for visually reproducing a stereoscopic image. This holographic stereogram is formed by arranging a plurality of element holograms. Each element hologram is loaded with its own modulation value corresponding to the stereoscopic image to be reproduced, and by irradiating these element holograms with coherent light,
The stereoscopic image is visually reproduced.

[0002]

2. Description of the Related Art FIG. 9 is a diagram for explaining a conventional computer one-dimensional holographic stereogram. In the figure, 10 is a holographic stereogram to be finally generated, and a plurality of element holograms 11
It is configured by arranging. Each element hologram 11 is loaded with a unique modulation value corresponding to the stereoscopic image to be reproduced. Each element hologram 11 is divided into a large number of cells.

According to the example of the figure, this element hologram 1
One house is shown as a stereoscopic image to be reproduced by 1. This image shows the diffracted light intensity distribution. The computer one-dimensional holographic stereogram 10 described above is known as a method for obtaining a stereoscopic image as a simpler method than an original hologram by omitting the vertical stereoscopic effect.

By the way, in the one-dimensional holographic stereogram, the pattern of element holograms (modulation values to be loaded) is set under the condition that "the viewpoint is sufficiently far compared to the size of element holograms". , It is known that the diffracted light intensity distribution (the image itself in the figure) in the horizontal direction (left and right in the figure) is equivalent to the Fourier transform. This will be apparent from FIG. 8 described later and the description thereof.

Based on this fact, in order to realize a computer one-dimensional holographic stereogram 10, as a conventional method for deriving a modulation value (pattern) to be loaded in each element hologram 11, (a) Fourier series Methods using expansion, (b) methods using discrete Fourier transform by discretizing the distribution of the diffracted light intensity with respect to the angle (the angle at which each point in the section AB is viewed from the center of the element hologram) are known. There is.

FIG. 9 illustrates the concept using the above method (a) or (b). With these techniques,
Since the viewing area is limited to the section AB shown in FIG.
As shown in, the actual intensity distribution of the diffracted light becomes periodic. This is usually called folding, and is represented by the dotted line image in the figure.
The modulation value distribution (element hologram pattern) obtained by the method (a) or (b) is displayed on a display device capable of spatially modulating the light intensity, for example, a liquid crystal,
In the case of (a), the one-dimensional Fourier series of the diffracted light intensity distribution in the section AB is loaded and the element hologram to be obtained is formed. In the same manner, all the other element holograms are formed and a computer one-dimensional holographic stereogram is obtained. The above also applies to the computer two-dimensional holographic stereogram.

FIG. 10 is a diagram for explaining a conventional computer two-dimensional holographic stereogram. This computer two-dimensional holographic stereogram is known as a simpler method than the original hologram as a method for obtaining a stereoscopic image because a simple calculation method is known when using a computer. Has been. Also in the case of this computer two-dimensional holographic stereogram, the method of (a) or (b) described above is adopted, and the viewing area is limited to the area "A" shown in FIG. It is carried out. Therefore, as shown in FIG. 10, the reproduced actual diffracted light intensity distribution is periodic (folded) as in FIG.

Further, as in the case of FIG. 9, the distribution of the modulation values (pattern of element holograms) obtained by the method of (a) or (b) is a display device capable of spatially modulating the light intensity, for example, In the case of (a), which is displayed on the liquid crystal, the element hologram to be obtained is formed by loading the two-dimensional Fourier series of the diffracted light intensity distribution to be reproduced in the area "A". In the same manner, all the other element holograms are formed and a computer two-dimensional holographic stereogram is obtained.

[0009]

When Fourier series expansion or discrete Fourier transform is performed to obtain the above-mentioned modulation value by the above-mentioned conventional method, the Fourier transform (F (ω)) of f (x) is generally obtained.

[0010]

[Equation 1]

Since it is represented by, not only the real number component but also the imaginary number component appears. This is common to both the above-mentioned computer primary and secondary holographic stereograms. For this reason, in order to faithfully reproduce the diffracted light intensity distribution, the display device must be able to modulate not only the amplitude (amplitude modulation) but also the refractive index (phase modulation). . For this reason, the drive system of the display device becomes complicated,
There is the first problem.

Further, it is generally known that in the Fourier transform, the transformed energy exists up to higher-order terms. As a result, it becomes difficult to satisfy the above-mentioned condition (the assumption) that the viewpoint is far enough compared to the size of the element hologram, and the faithful reproduction of the diffracted light intensity distribution is hindered. There's a problem. Therefore, in view of the above problems, the present invention can simplify a drive system of a display device for visually reproducing a three-dimensional image, and can also faithfully reproduce a diffracted light intensity distribution exactly as an original three-dimensional image. It is intended to provide a stereogram.

[0013]

FIG. 1 is a diagram for explaining a computer one-dimensional holographic stereogram according to the present invention. FIG. 2 is a diagram for explaining a computer two-dimensional holographic stereogram according to the present invention. A plurality of element holograms 11 each loaded with a unique modulation value corresponding to a stereoscopic image to be reproduced
In the holographic stereogram of the present invention in which these element holograms 11 are irradiated with coherent light to reproduce the stereoscopic image, each element hologram has a diffracted light intensity representing the stereoscopic image to be reproduced. The conversion value obtained by performing sine transformation or discrete sine transformation on the distribution is used as the above-mentioned modulation value.

More specifically, on the display device such as the liquid crystal described above, the amplitude of each element hologram 11 is changed in accordance with the above modulation value to form each element hologram. Loads each element hologram 11 with a modulation value consisting of a one-dimensional sine transform coefficient and arranges it in one direction to realize a computer one-dimensional holographic stereogram. Also in FIG.
A modulation value composed of a two-dimensional sine transform coefficient is loaded into each of the element holograms 11 and arranged two-dimensionally to realize a computer two-dimensional holographic stereogram.

[0015]

First, referring to FIG. 1, although a diffracted light intensity distribution originally required to be reproduced exists in a section AB, a section BC having a virtually bilaterally symmetric diffracted light intensity distribution with inverted intensity. It is also considered that (the "right-left inverted and intensity-inverted distribution" in the figure) is reproduced at the same time as the section AB.
That is, the section AC is formed as a hologram. In the figure, in order to give an image of intensity inversion, the lightness and darkness of each portion is represented by the presence or absence of hatching. In order to reproduce such a diffracted light intensity distribution, the above-mentioned modulation value (pattern) to be loaded on the element hologram 11 is converted into the diffracted light intensity distribution existing in the section AC according to the conventional method described above. On the other hand, the Fourier series expansion or the discrete Fourier transform will be performed.

However, the modulation value of the section AC obtained here has no cosine component. This is because, in FIG. 1, the distribution of the section AC is symmetrical with respect to the point B between them and the intensity is inverted, and the distribution of the section AC is an odd function, so that the above-mentioned e ^jxt (= c
The cosine component of osxt + jsinxt) disappears.

After all, the Fourier transform for the intensity distribution in the section AC is equivalent to the sine or discrete sine transform for the intensity distribution in the section AB. In this case, as the distribution of the section BC, a distribution in which the right and left are inverted and the intensity is inverted is virtually introduced, but this section BC is outside the visual range of the section AB, and there is no problem in introducing the section BC. In the above-mentioned sine transform and discrete sine transform, all transform coefficients (modulation values to be loaded) have a constant phase, that is, π / 2. Therefore, when realizing the display device, only the amplitude needs to be modulated, and the drive system of the display device is simplified. Generally, when considering the vector cos θ + jsin θ, if neither the cos θ component nor the sin θ component is 0, the phase component (θ) represented by tan θ (= sin θ / cos θ) appears, so that not only the amplitude modulation but also the It is also necessary to consider the modulation of the phase (refractive index). However, since the cosine component is 0 as described above, it is only necessary to obtain the modulation value for the amplitude.

Furthermore, it is easily understood that the above-mentioned sine transform and discrete sine transform correspond to the orthogonal transform in the generally known image data processing technique, and therefore the above transform coefficients are concentrated in the low-order terms. To be done. As a result,
It is possible to sufficiently satisfy the above-mentioned condition (assumed) that the viewpoint is sufficiently far compared to the size of the element hologram, and it is possible to faithfully reproduce the diffracted light intensity distribution.

The above also applies to the computer two-dimensional holographic stereogram shown in FIG. First, referring to FIG. 2, although the diffracted light intensity distribution originally required to be reproduced exists in the region “A”, it is virtually a region “A” having a vertically and horizontally symmetrical diffracted light intensity distribution. B "," C "and" D "(" horizontal inversion "in the figure,
"Upside down, left and right inversion" and "Upside down, upside down" are also the area
At the same time, consider reproducing. That is, areas "A", "B", "C" and "D" are formed as the hologram. The intensity inversion is indicated by hatching. According to the above-mentioned conventional method, the modulation values (patterns) to be loaded on the element hologram 11 in order to reproduce such a diffracted light intensity distribution are the areas "A", "B", "C". Then, the two-dimensional Fourier series expansion or the two-dimensional discrete Fourier transform is performed on the diffracted light intensity distribution existing in “D”.

However, the areas "A", "B", obtained here,
As described above, the cosine component does not exist in the “C” and “D” modulation values. After all, the two-dimensional Fourier transform for the intensity distribution in the areas "A" to "D" is equivalent to the two-dimensional sine transform or the two-dimensional discrete sine transform for the intensity distribution in the area "A". In this case, as the distributions of the regions "B", "C" and "D", a distribution which is inverted vertically and horizontally and is inverted in intensity is virtually introduced, but these regions "B", "C" and "D" are , Out of the viewing area of area “A”, and in areas “B”, “C” and “D”
There is no problem with the introduction of.

In the above-mentioned two-dimensional sine transform and two-dimensional discrete sine transform, a two-dimensional transform coefficient (modulation value to be loaded)
Are all real numbers. Therefore, when realizing the display device, only the amplitude needs to be modulated, and the drive system of the display device is simplified. Furthermore, the above-mentioned two-dimensional sine transform and two-dimensional discrete sine transform correspond to orthogonal transform in a generally known image data processing technique, and therefore, the above-mentioned two-dimensional transform coefficient can be concentrated on low-order terms. Easily understood. As a result, it is possible to sufficiently satisfy the above-mentioned condition (the assumption) that the viewpoint is far enough compared to the size of the element hologram, and it is possible to faithfully reproduce the diffracted light intensity distribution.

[0022]

FIG. 3 is a diagram showing an embodiment of a procedure for creating a holographic stereogram according to the present invention. It should be noted that the embodiment of this figure can be commonly applied to both the computer one-dimensional holographic stereogram and the computer two-dimensional holographic stereogram. In this embodiment, CAD data is displayed as a stereoscopic image using a workstation.
The CAD data is three-dimensional (Dimension) data representing the three-dimensional coordinates of the stereoscopic image. This is shown as 3D data in block a in the figure.

Next, a diffracted light intensity distribution (corresponding to an image of a single house shown in FIG. 1 or 2) to be reproduced by a certain element hologram 11 is obtained. This is shown in block b in the figure. The steps up to this point are conventional. The feature of the present invention is shown in block c, where sine transformation is performed on the diffracted light intensity distribution. The one-dimensional or two-dimensional conversion coefficient obtained here is loaded into each element hologram as the modulation value.

A modulation value corresponding to each element hologram is loaded on the display device 12 formed of, for example, liquid crystal to obtain a desired pattern. When the display device 12 thus realized is irradiated with the coherent light (reproduction light) 13, the stereoscopic image specified by the 3D data can be viewed. In FIG. 3, an example of a method of loading the one-dimensional or two-dimensional conversion coefficient (modulation value) obtained by performing the sine conversion on the display device 12 corresponding to each element hologram is as follows.

That is, assuming that the number of samples for each elementary hologram 11 is N (N is a positive integer), the sine transform coefficient is loaded into 2N points. Each sine transform coefficient corresponding thereto is loaded as described later with reference to FIGS. 4 and 5.

FIG. 4 is a diagram showing how to load the sine transform coefficient into the display device. Further, FIG. 5 is a diagram for mathematically explaining the discrete sine transform for the 2N-point samples. Generally speaking, assuming that the number of samples of each element hologram is N (N is a positive integer), N sine transform coefficients and other N sine transform coefficients obtained by rearranging or inverting the sine transform coefficients. Both sine transform coefficients are generated over the 2N modulator elements, which are loaded onto the display device. In this case, the description has been made with reference to a one-dimensional holographic stereogram, but a similar description applies to a two-dimensional holographic stereogram. In the latter two-dimensional case, not only the 2N modulator elements described above are developed along the X axis as described above, but also the Y element is developed along the Y axis.
Here, these XY axes are two-dimensional holograms (2N × 2
N) defines the orthogonal axis.

The loading of the transform coefficient of the holographic stereogram when the discrete sine transform coefficient is used will be described below. N arranged along the spatial axis
The function f _n (n = 0 to N−1) at each point is represented by the function F _k of the following equation according to the discrete sine transform. Here, the function f _n represents an image to be reproduced in the actual space.

[0028]

[Equation 2]

The above equation (2) represents the definition of the discrete sine transform. In order to actually display the image to be reproduced, it is necessary to load 2N coefficients on the display device 12. This will be described with reference to the following two cases, that is, Case 1 and Case 2.

Case 1 The 2N points, that is, F ₀ to F _2N−1 , have k from 0 to N.
It is then loaded onto the display device by taking up to 2N-1 (see Figure 4). When 2N-1 ≧ k ≧ N and k ′ is k ′ = 2N−k, k is k = 2N−
It can be expressed as k '. Substituting this into equation (2) above,
The following equation (3) is obtained.

[0031]

[Equation 3]

When k = 0, the formula F ₀ = 0 holds. The above 2N points are loaded on the display device 12. The display device 12 thus loaded is shown in FIG.
As shown in, the light intensity at the point m in the space (see FIG. 8) where the image is to be displayed by irradiation with the coherent light 13 is calculated by the following equation (4).

[0033]

[Equation 4]

In the above equation (4), the first term, that is,

[0035]

[Equation 5]

Represents the wave front that reaches the point m in the display space when the light illuminates the display device at the point k. On the other hand, the second term, or "F _k ", represents the modulation factor at point k on the display device. The above equation (4) can be rewritten as the following equation (5).

[0037]

[Equation 6]

In the above equation, F _N = 0 and

[0039]

[Equation 7]

Since the above condition is established, it can be rewritten as the following equation.

[0041]

[Equation 8]

In the above equation,

[0043]

[Equation 9]

The term of represents the inverse discrete sine transform for reproducing the original image at the point m, ie f _m . Therefore, the following equation holds. j2Nαf _m ∝f _m, that is, j2Nαf _m representing the result is proportional to the intensity of the image to be reproduced. In case 1 described above, the N discrete sine transform coefficients are expanded over the 2N points indicated by "2N modulator elements (case 1)" in FIG.

Case 2 Case 2 differs from Case 1 described above in the way of loading.
In case 2, the 2N points are selected by taking k from-(N-1) to N. Of these, k =-(N-
Regarding 1) to N, the above-mentioned expression (2) is expressed as the following expression (8).

[0046]

[Equation 10]

The above 2N points are loaded on the display device 12. The display device 12 thus loaded is
Illuminated by coherent light 13 as shown in FIG.
The light intensity at the point m on the space where the image is to be displayed (see FIG. 8) is calculated by the following equation (9).

[0048]

[Equation 11]

The term in the above equation (9), that is,

[0050]

[Equation 12]

The term of represents the inverse discrete sine transform for reproducing the original image at the point m, ie f _m . Therefore, the following equation holds. j2Nαf _m ∝f _m, that is, j2Nαf _m representing the result is proportional to the intensity of the image to be reproduced. In case 2 described above, the N discrete sine transform coefficients are expanded over the 2N points indicated by "2N modulator elements (case 2)" in FIG.

As described above, the holographic stereogram is established under the condition that "the viewpoint is far away from the size of the element hologram". Therefore, if this condition is not satisfied, the desired diffracted light intensity distribution cannot be obtained. Specifically, the high frequency component of the diffracted light intensity distribution is lost, resulting in a blurry distribution.

Therefore, in order to reproduce the desired diffracted light intensity distribution of each element hologram, in the present invention, further, (i) in each element hologram, the refractive index gradually increases as the distance from the center thereof increases. Compensation is added in advance so that the modulation degree changes. (Ii) Further, the compensation amount is corrected according to the variation in the distance between the element hologram and the viewpoint.

FIG. 6 is a diagram showing a state in which the degree of refractive index modulation is compensated for the element hologram, and FIG. 7 shows that the compensation amount is corrected in accordance with the change in the distance between the element hologram and the viewpoint. FIG. FIG. 6 corresponds to (i) above, and FIG. 7 corresponds to (ii) above. As described above, the degree of modulation in each element hologram is only a value that depends on the distance from the center on the element hologram to the point where the incident coherent light 13 is actually modulated and the distance from the element hologram to the viewpoint. By correcting, it is possible to realize a holographic stereogram that can faithfully reproduce the diffracted light intensity distribution up to high frequency components. Hereinafter, the above items will be described in detail.

First, the value for modulating the incident coherent light is exp (jkx ² / 2L) from the value obtained by performing the Fourier transform (the same applies to the sine transform) at each point of the element hologram, where j: complex unit x : The distance from the center of the element hologram of the coefficient k: The wave number L of the incident coherent light beam: The distance from the element hologram to the viewpoint is deviated by a multiple. This is proved below.

FIG. 8 is a diagram for explaining compensation of the refractive index modulation degree. Holographic image as shown in Figure 8
Consider a stereogram element hologram 11. The incident angle of coherent light on the element hologram 11 is φ. On the circular screen where the light modulation degree distribution n (x) of the element hologram is separated from the center O of this element hologram by L,
Consider generation of diffraction having a light intensity distribution of I (θ).

Now, point O (x = 0) and point P (x
= X₀), The point Q (θ
= Θ₀) To find the optical path difference. First, enter points O and P
Optical path difference l of incoming light 13₁Is l₁= X₀・ Sin φ Becomes Also, the optical path difference l of (OQ-PQ)₂Is l₂= OQ-PQ = L- (L²+ X₀ ²-2x₀・ L ・ sin θ₀)^1/2 ≒ x₀・ Sin θ₀-X₀ ²/ 2L Therefore, the total optical path difference l is l = l₁-L₂ = X₀・ Sin φ-x₀・ Sin θ₀+ X₀ ²/ 2L From this, the light intensity observed at point Q is k
As the wave number of the coherent light, the entire surface of the element hologram 11
Integrate the light from   I (θ₀) ＝ ∫n (x) ・ exp (-jk (x ・ sinφ-x ・ sinθ₀+ x²/ 2L)) ・ dx           ＝ ∫n (x) ・ exp (-jkx²/ 2L) ・ exp (-jk (sin φ-sin θ₀) x) ・ dx here, Θ = sin φ-sin θ₀ When the variable conversion is I (Θ) =∫n (x) ・ exp (-jkx ² / 2L)・exp (-jkΘx)・ Dx Next I (Θ) isn (x) · exp (-jkx 2/2
L)You can see that it is the inverse Fourier transform of. this
Rather thann (x) · exp (-jkx ² / 2L)Section
Is the Fourier transform of I (Θ). That is, n (x) ・ exp (-jkx²/ 2L) ∝∫I (Θ) ・ exp (jkΘx) ・ dΘ Is. From the above, the desired diffracted light intensity distribution is reproduced
The optical modulation distribution of the element hologram is And the Fourier (sine) change of the desired diffracted light intensity distribution
Alternatively, it can be obtained by multiplying the compensation term in the same way. In addition,
The above discussion is the same for both one-dimensional and two-dimensional cases.
Is established.

As seen from the last equation above, the value of the compensation term depends only on the distance x from the center of each element hologram and the distance L from the center of the element hologram to the viewpoint, and does not depend on the viewing angle θ. . This fact is the same even when the two-dimensional Fourier transform (two-dimensional sine transform) is used. Further, this compensation value is only the phase component. This actually means that only the optical path difference in the display device 12, that is, the refractive index needs to be changed. From these facts, in order to reproduce the desired diffracted light intensity distribution, the following compensation may be applied.

First, consider the case where the position of the viewer's viewpoint from the hologram is made substantially constant. In this case, among the compensation terms described above, L is almost fixed, so this compensation term depends only on the value from the center of each element hologram. That is, it can be calculated in advance. Therefore, change the refractive index by this optical path difference with respect to the calculated modulation value,
Alternatively, it is possible to embed the refractive index for realizing this optical path difference in the display device 12 from the beginning (FIG. 6).

Further, when the viewer's viewpoint changes, the hologram (1
It is possible to measure the distance from (0) to the viewer's head, calculate the compensation value calculated according to the distance, and multiply it by the value obtained by the Fourier transform (FIG. 7). With the above method, you can obtain the desired diffracted light intensity distribution,
It is possible to realize a holographic stereogram that can faithfully reproduce even high-frequency components.

The following are some specific numerical examples. Distance to viewpoint: L = 300 mm = 3.00 × 10 ⁻¹ m Wavelength of incident light: λ = 633 nm = 6.33 × 10 ⁻⁷ m Wave number: k = 2π / λ = 9.93 × 10 ⁶ rad /
m In this case, the compensation term is

[0062]

[Equation 13]

It becomes From the above, assuming that x is the distance (μm) from the center of the element hologram, the refractive index distribution n (x) to be actually compensated is given that the thickness Δ of the refractive index variable portion is 2 μm.

[0064]

[Equation 14]

It becomes Actually, the phase can be changed from 0 to 2π, so the refractive index

[0066]

[Equation 15]

It becomes Compensation is performed by applying a concentric refractive index distribution as shown in FIG. 6 to the display device 12 according to this equation.

[0068]

As described above, according to the present invention, since only the amplitude modulation needs to be handled, there is an advantage that the drive system of the display device for reproducing a stereoscopic image is simplified. Further, since the sine transform is essentially equivalent to the orthogonal transform of the image data, the sine transform coefficient concentrates on the low-order terms, and therefore the original stereoscopic image can be reproduced faithfully.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a computer one-dimensional holographic stereogram according to the present invention.

FIG. 2 is a diagram for explaining a computer two-dimensional holographic stereogram according to the present invention.

FIG. 3 is a diagram showing an embodiment of a procedure for creating a holographic stereogram according to the present invention.

FIG. 4 is a diagram showing how to load a sine transform coefficient into a display device.

FIG. 5 is a diagram for mathematically explaining discrete sine transform for 2N-point samples.

FIG. 6 is a diagram showing a state in which compensation for a refractive index modulation degree is added to an element hologram.

FIG. 7 is a diagram showing that the compensation amount is corrected according to the variation in the distance between the element hologram and the viewpoint.

FIG. 8 is a diagram for explaining compensation of a refractive index modulation degree.

FIG. 9 is a diagram for explaining a conventional computer one-dimensional holographic stereogram.

FIG. 10 is a diagram for explaining a conventional computer two-dimensional holographic stereogram.

[Explanation of symbols]

10 ... Holographic stereogram 11 ... Element hologram 12 ... Display device 13 ... Coherent light

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiichi Matsuda 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) References JP-A-6-110370 (JP, A) JP-A-6-195017 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03H 1/08

Claims (7)

(57) [Claims] 1. A plurality of element holograms (1) each loaded with a unique modulation value corresponding to a stereoscopic image to be reproduced.
In the holographic stereogram (10) which is configured by arranging 1) and reproduces the stereoscopic image by irradiating these element holograms with coherent light (13), each of the element holograms is the stereoscopic image to be reproduced. A holographic stereogram characterized in that a sine transform coefficient obtained by performing a sine transform or a discrete sine transform on a diffracted light intensity distribution representing is a modulation value. 2. The holographic stereogram according to claim 1, wherein on the display device (12), the element hologram is formed by changing the amplitude according to the modulation value corresponding to each of the element holograms (11). . 3. When the number of samples of each element hologram (11) is N (N is a positive integer), N sine transform coefficients obtained by rearranging or inverting the sine transform coefficients and others. 3. The holographic stereogram according to claim 2, wherein both N sine transform coefficients are generated over the 2N modulator elements, which are loaded on the display device (12). 4. The holographic stereogram according to claim 2, wherein in each of said elementary holograms, compensation is added in advance so that the degree of refractive index modulation gradually changes as the distance from the center thereof increases. . 5. The holographic stereogram according to claim 4, wherein the compensation amount is corrected in accordance with a change in the distance between the element hologram (11) and the viewpoint. 6. A computer one-dimensional holographic stereogram is realized by loading each of the elementary holograms (11) with the modulation value consisting of a one-dimensional sine transform coefficient and arranging the modulation values in one direction. Holographic stereogram. 7. The computer generated two-dimensional holographic stereogram according to claim 2, wherein each of the element holograms (11) is loaded with the modulation value composed of a two-dimensional sine transform coefficient and arranged two-dimensionally. Holographic stereogram described.