JP2012008220A - Method for calculating computer-synthesized hologram using lookup table and spatial overlapping of image, and apparatus thereof - Google Patents

Abstract

A computer-generated hologram calculation method and apparatus using a look-up table and spatial overlap of images, in which a memory capacity required for hologram calculation is reduced.
A method for calculating a hologram according to the present invention includes a step of calculating one reference element fringe pattern for each point separated from a reference point on a hologram plane of a target object by the same distance, and a reference element fringe pattern. Storing in accordance with the distance from the reference point to each point of the target object, calculating the identity data indicating whether each point of the input image and the adjacent point are the same, and n references Calculating an n-point element fringe pattern obtained by synthesizing element fringe patterns; and calculating hologram information by matching n-point element fringe patterns obtained from identity data. It is characterized by.
[Selection] Figure 2

Description

  The present invention relates to a method for calculating a hologram, and more particularly, a method for calculating a computer generated hologram (CGH) using a look-up table (LUT) and spatial redundancy (CGH: Computer Generated Hologram) and the method thereof. Relates to the device.

  Recently, research on three-dimensional images and image reproduction technologies has been actively carried out, and development of next-generation displays is expected as a new concept actual image media that further raises the level of visual information. In addition, the demand for 3D images is increasing because 3D images are more realistic than 2D images, appear more natural, and are closer to the reality felt by humans.

  Among three-dimensional image-related technologies, the holography method is a method of observing a stereoscopic image of a virtual image by observing the holography at a predetermined distance away from the front surface of the holography when the holography is illuminated with light.

  The holography method is a method for observing a holography manufactured using a laser so that a stereoscopic image similar to a real object can be felt without wearing special glasses. Therefore, the holography method is excellent in stereoscopic effect, and can be said to be the most ideal method for enjoying a three-dimensional image without a human being feeling tired.

  Usually, when calculating a hologram pattern, a ray-tracing method for calculating light diffraction is mainly used. At this time, the target object is regarded as a set of points, and a hologram pattern for each point is calculated and added. However, this method has a problem that real time reproduction is difficult due to a large amount of calculation.

  In order to overcome such problems, a method for calculating a hologram using a lookup table has been proposed. In this method, after calculating element fringes for all points in a possible area in advance, when calculating a hologram, the element fringes corresponding to the points of the target object are called up and summed up. It was possible. However, this method has a problem that the larger the object area, the larger the number of element fringes required, so that the lookup table becomes very large.

  In order to solve such a problem, a new look-up table N that can dramatically reduce the memory capacity of the look-up table while maintaining the high hologram calculation speed as in the existing look-up table method. A -LUT (novel look-up table) method has been proposed. However, this method cannot be practically applied because the number of points to be calculated increases as the resolution of the image to be calculated increases, and as a result, the calculation time increases.

In view of the problems of the prior art, an object of the present invention is to provide a computer-generated hologram calculation method and apparatus using a look-up table capable of reproducing a moving image hologram in real time and spatial redundancy.
Still other objects of the present invention will be easily understood through the following description.

  According to an embodiment of the present invention, calculating one reference element fringe pattern for each point separated by the same distance from a reference point on the hologram plane of the target object; Storing according to the distance from the point to each point of the target object, calculating the identity data indicating whether each point of the input image and the adjacent point are the same, and n number of the above Calculating an n-point element fringe pattern obtained by synthesizing a reference element fringe pattern; and calculating hologram information by matching an n-continuous point obtained from the identity data with the n-point element fringe pattern; And n is a natural number.

  According to another embodiment of the present invention, a fringe calculation unit that calculates one reference element fringe pattern for each point of the target object that is separated from the reference point on the hologram plane by the same distance, and the reference element fringe pattern And an identity analysis that calculates identity data indicating whether each point of the input image and the adjacent point are the same, and a look-up table that stores information according to the distance from the reference point to each point of the target object A point fringe calculation unit that calculates an n-point element fringe pattern obtained by combining the n reference element fringe patterns, and an n-continuous point obtained from the identity data and the n-point element fringe pattern And a hologram calculation unit for calculating hologram information, wherein n is a natural number It is provided.

The computer-generated hologram calculation method and apparatus using the look-up table and spatial redundancy according to the present invention have an effect that the hologram can be calculated in real time.
In addition, the calculation method and apparatus for a moving image computer-generated hologram using the look-up table and spatial redundancy according to the present invention have the effect of significantly reducing the memory required for hologram calculation.
The above summary of the invention does not enumerate all necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

3 is a diagram illustrating a method for acquiring three-dimensional information using holography technology according to an embodiment of the present invention. 1 is a diagram illustrating a hologram calculation apparatus according to an embodiment of the present invention. 4 is a diagram illustrating a brightness image and a depth image according to an exemplary embodiment of the present invention. 4 is a diagram illustrating an element fringe pattern for three points according to an exemplary embodiment of the present invention. 3 is a diagram illustrating a reference element fringe pattern and an n-point element fringe pattern according to an embodiment of the present invention; 4 is a diagram illustrating a method of calculating a hologram pattern using spatial redundancy data and an element fringe pattern for n points calculated according to an embodiment of the present invention. 3 is a diagram illustrating a hologram calculation process according to an exemplary embodiment of the present invention. 6 is a diagram illustrating a process of calculating hologram information by matching a reference element fringe pattern and an n-point element fringe pattern according to an embodiment of the present invention.

  Since the present invention can be modified in various ways and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail herein. However, this is not to be construed as limiting the invention to the specific embodiments, but is to be understood as including all transformations, equivalents, and alternatives falling within the spirit and scope of the invention.

  The terms used in the present application are merely used to describe particular embodiments, and are not intended to limit the present invention. A singular expression includes the plural expression unless it is explicitly expressed in a sentence. In this application, terms such as “comprising” or “having” specify the presence of a feature, number, step, action, component, part, or combination thereof as described in the specification, It should be understood that the existence or additional possibilities of one or more other features or numbers, steps, actions, components, parts, or combinations thereof are not excluded in advance.

  Unless otherwise defined, all terms used herein, including technical or scientific terms, are those commonly understood by those having ordinary skill in the art to which this invention belongs. Have the same meaning. Terms commonly defined as used should be construed as having a meaning consistent with the contextual meaning of the related art, and are ideal or overly formal unless clearly defined herein. Do not interpret as meaning.

  Hereinafter, a preferred embodiment of a computer-generated hologram calculation method and apparatus using a look-up table and image spatial overlap according to the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted. In the description of the present invention, when it is determined that the specific description of the known technology is obscured instead of the gist of the present invention, the detailed description thereof is omitted. Also, before describing the preferred embodiment of the present invention in detail, a general principle and system for acquiring three-dimensional information using holographic techniques will be described.

  FIG. 1 is a diagram illustrating a 3D information acquisition method using a holography technique according to an embodiment of the present invention.

  The principle of the hologram is that the light emitted from the laser is split into two, one light directly illuminates the screen and the other light illuminates the target object. At this time, a light beam that directly illuminates the screen is referred to as a reference beam (reference beam 120), and a light beam that illuminates an object is referred to as an object beam.

  Since the object light is a light beam reflected from each surface of the object, the phase difference appears differently depending on the distance from the object surface to the screen. At this time, the reference light that is not deformed interferes with the object light, and the interference fringes at this time are stored in the screen. A film in which such interference fringes are stored is called a hologram.

  The pattern of a computer generated hologram (CGH: Computer Generated Hologram, hereinafter also referred to as CGH) is calculated by computer calculation based on the (x, y, z) coordinate value and the intensity value (I) of the pixel. The calculated CGH is used to acquire a three-dimensional hologram image. FIG. 1 shows a geometric calculation model of a hologram. Hereinafter, the description will focus on such CGH, but the present invention is not limited to this.

Hologram is located on the x-y plane 130, the object p-th point position _{(x p, y p,} z p) in 110. a _p and Φ _p indicate the strength and phase of each point, and these are used by the computer to calculate the following general formula.

  The complex amplitude O (x, y) in the hologram is obtained by superimposing the object light as shown in the following general formula (1).

In the equation, p indicates a point (object point) constituting the object, and N is the total number of points constituting the object. _ap indicates the intensity of object light, k is a wave vector, and is defined as k = 2π / λ. λ is the wavelength of light in free space. r _p represents the distance of the diagonal between the p-th object point and the point in the hologram (x, y, 0), is defined by the following general formula (2).

  Further, the complex amplitude R (x, y) of the reference light that is planar light is obtained from the following general formula (3).

In the formula, a _R and θ _R indicate the intensity and incident angle of the reference light, respectively. The overall grating intensity I (x, y) on the hologram surface is an interference pattern between the object light O (x, y) and the reference light R (x, y), and is represented by the following general formula (4). expressed.

In the equation, | R (x, y) | ² indicates the intensity of the reference light, and | O (x, y) | ² indicates the intensity of the object light. 2 | R (x, y) || O (x, y) | cos [kr p + kxsinθ R + φ p] denotes the interference pattern between the object beam and the reference light including a hologram information partially object Contains phase information for spatial position of light.

In the following general formula (5), the hologram information is included only in 2 | R (x, y) || O (x, y) | cos [kr _p + kxsin θ _R + φ _p ], so I (x, y) can be expressed as:

  In the case of the conventional ray tracing method, the hologram pattern is calculated from the general formula (5). However, as shown in the general formula (5), the formula for calculating the hologram pattern is very complicated, and it is difficult to calculate in real time.

  In order to solve such a problem, an element fringe pattern representing all points in an arbitrary object space is created in advance and stored in a lookup table, and each corresponding to the three-dimensional image to be calculated is calculated. A method using a look-up table in which an element fringe pattern is taken out and a hologram is calculated has been proposed.

  Prior to describing such components, the premise of the embodiment of the present invention will be described below. In general, the image space is not discrete. However, due to the limited capabilities of the human visual system, if the degree of discretization is so small that it is not perceptible to the human eye, the two points are perceived as not separated, ie continuous. . For example, a human recognizes two points having an interval of 3 milliradians as one point. Therefore, when an image is viewed at a distance of 500 mm, two points having an interval of 500 mm × 0.003 = 150 microns or less are recognized as one point. Hereinafter, an embodiment according to the present invention will be described with the vertical and horizontal discretization levels set to 150 microns.

When using a lookup table, the element fringe pattern must be calculated in advance. It is an element fringe pattern T (x, y; x _p , y _p , z _p ) of the reference brightness expressing each point, and is expressed by the general formula (5) as in the general formula (6). Can be represented.

Wherein the r _p a distance between the p-th point and the (x, y, 0), is obtained from the formula (2).

According to this method, when calculating the hologram, the fringe pattern for each point is not calculated from the general formula (5) whenever necessary, but each point (x _p , y _p , z calculated in advance) is calculated. It is calculated using a look-up table that is a set of fringe patterns for _p ). Accordingly, the hologram information I (x, y) in the look-up table method is finally expressed by the general formula (7), where N indicates the number of object points.

  According to the method using such a lookup table, the generation speed of the hologram can be improved by using the element fringe pattern calculated in advance for all possible points of the object image. However, the biggest disadvantage of this method is that the amount of the element fringe pattern calculated in advance is very large, so that the memory of the look-up table for storing this is considerably increased. For example, in the lookup table method, assuming that the object space is 100 (horizontal) × 100 (vertical) × 100 (depth) and the capacity of each element fringe pattern is 1 MB, the memory capacity of the entire lookup table is 1 MB. * 100 * 100 * 100 = 1 TB is required.

  In order to solve such a problem, it is a new type of lookup table that can dramatically reduce the memory capacity of the lookup table while maintaining a high calculation speed as it is in the existing lookup table method. An N-LUT has been proposed, and a high-speed digital hologram calculation method using the N-LUT has been proposed. That is, in the N-LUT method, only the element fringe pattern with respect to the depth direction of the object is calculated and stored. Then, when one depth direction of the object is determined, the element fringe pattern of the object point existing on the surface is calculated and stored in advance, and the element fringe pattern of the depth is moved to the left and right to each object point. Can be calculated and added to calculate the hologram pattern in the depth plane.

  By calculating and adding holograms in all depth planes of the object in a similar manner, a hologram pattern for the entire object can be calculated. Therefore, in the existing look-up table method, the element fringe pattern for the object points in all the horizontal, vertical, and depth directions must be stored. In the proposed N-LUT method, the depth of the object is stored. Since only the element fringe pattern for the direction needs to be stored in advance, the memory requirement is significantly reduced.

Even in the N-LUT method, the element fringe pattern must be calculated in advance. That is, each element fringe pattern T (x, y; z _p ) is a Fresnel zone plate having a reference strength with respect to each depth, and can be expressed as follows.

Wherein the r _p a distance between the p-th point and the (x, y, 0), is obtained from the formula (2). Therefore, in the newly presented N-LUT method, only the element fringe pattern (hereinafter referred to as a reference element fringe pattern) with respect to the depth direction of the object is calculated and stored, and when one depth direction of the object is determined, The element fringe pattern of the object point existing in the object can be calculated by moving the reference element fringe pattern of the depth stored in advance to each object point and calculating the fringe pattern. . A hologram pattern for the entire object can be calculated by calculating and summing up the respective holograms in all depth planes of the object in a similar manner. Therefore, in the look-up table method, the hologram information I (x, y) can be finally expressed as in the general formula (9).

  A hologram pattern can be calculated at high speed and restored using the above-described N-LUT method. However, this method also has a problem that the number of points to be calculated increases and the calculation becomes complicated as the resolution of the image to be calculated increases.

  FIG. 2 is a diagram illustrating a hologram calculation apparatus according to an embodiment of the present invention, FIG. 3 is a diagram illustrating a brightness image and a depth image according to an embodiment of the present invention, and FIG. FIG. 5 illustrates an element fringe pattern for three points according to an embodiment, and FIG. 5 illustrates a reference element fringe pattern and an n-point element fringe pattern according to an embodiment of the present invention.

  Referring to FIG. 2, the hologram calculation apparatus includes an extraction unit 210, an identity analysis unit 220, a fringe calculation unit 230, a point fringe calculation unit 240, a lookup table 250, and a hologram calculation unit 260.

  The extraction unit 210 extracts a brightness image and a depth image. The brightness image indicates the brightness of an image included in a general two-dimensional image. The depth image is an image indicating depth information of the brightness image. FIG. 3 shows the output of the brightness image 310 and the depth image 320. The extraction unit 210 combines the brightness image 310 and the depth image 320 in a predetermined format and outputs an input image to the identity analysis unit 220.

  The identity analysis unit 220 extracts identity data from the three-dimensional image according to spatial redundancy. In a typical image, adjacent pixels have similar brightness values. That is, a general image has spatial redundancy. Even in a three-dimensional image, adjacent pixels have similar brightness and depth values. In addition, there are points having the same brightness and depth values in some areas.

The identity analysis unit 220 calculates identity data that collectively extracts points having the same brightness and depth values. For example, the identity analysis unit 220 compares the brightness and depth values of the point A (0, 0, 0) and the point B (1, 0, 0) existing on the three-dimensional coordinates, and if they are the same, , Identity data indicating the identity of points A and B is generated. Further, the identity analysis unit 220 can perform identity analysis not only on two points but also on three or more consecutive points. Hereinafter, when the brightness and depth values of adjacent n points are the same, the adjacent n points are referred to as n-continuous points.
The identity analyzer 220 outputs the calculated identity data to the point fringe calculator 240 and the hologram calculator 260.

  The fringe calculation unit 230 calculates a reference element fringe pattern for the target object. As described in detail in the example of the general formula (9), the fringe calculation unit 230 calculates a reference element fringe pattern required when using the N-LUT method and outputs the reference element fringe pattern to the lookup table 250.

  The point fringe calculation unit 240 receives the identity data and the reference element fringe pattern and calculates an n-point element fringe pattern. The n-point element fringe pattern is an element fringe pattern that represents a hologram pattern for n-continuous points. Hereinafter, the n-point element fringe pattern will be described in detail with reference to FIG.

  An n-point element fringe pattern capable of calculating a hologram pattern corresponding to a plurality of points at once can be obtained as shown in FIG. If there is a reference element fringe pattern 420 for one point, and a distance between adjacent points is assumed to be d, and a 3-point element fringe pattern 420 for three adjacent points 410 is formed, the reference element fringe pattern 420 for one point is Shift according to the position of each point. That is, the element fringe pattern 431 at the original position, the element fringe pattern 432 shifted by d to represent a point separated by d, and the element fringe shifted by 2d to represent a point separated by 2d A pattern 433 is calculated. By adding the three element fringe patterns, a 3-point element fringe pattern 440 that can represent three adjacent points is calculated.

Therefore, the n-point element fringe pattern Tn (x, y; z _p ) for the n-continuous points can be finally expressed as in the general formula (10).

  In the above description, the element fringe pattern for 3-continuous points has been calculated. However, it is obvious that a similar method can be used to express other numbers of adjacent points. FIG. 5 shows a 2-point element fringe pattern 520 and a 3-point element fringe pattern 530 generated using the reference element fringe pattern 510 by the method described above.

  Referring to FIG. 2 again, the point fringe calculation unit 240 calculates an n-point element fringe pattern and outputs it to the lookup table 250.

  The look-up table 250 is a space for storing one reference element fringe pattern and n-point element fringe pattern for each point of the target object separated from the reference point on the hologram plane by the same distance. The reference element fringe pattern of the lookup table 250 can be calculated from the general formula (8) described above. Here, the lookup table 250 outputs the reference element fringe pattern and the n-point element fringe pattern to the hologram calculation unit 260.

  The hologram calculation unit 260 receives the reference element fringe pattern, the identity data, and the n-point element fringe pattern and calculates a hologram.

FIG. 6 is a diagram illustrating a method of calculating a hologram pattern using spatial redundancy data and an element fringe pattern for n-continuous points calculated according to an embodiment of the present invention. Referring to FIG. 6, six point light sources are shown in an input image 610 according to an embodiment of the present invention. Among these, the z ₁ depth plane image 620 includes (−x ₁ , y ₁ , z ₁ ) and 3-continuous points composed of two adjacent points, and the z ₂ depth plane image 650 includes ( x ₂ , −y ₂ , z ₂ ) and two consecutive points adjacent thereto. In the composite image 640 with respect to the z ₁ depth plane, since the reference point light source A is located at (−x ₁ , y ₁ , z ₁ ), the hologram calculator 260 converts the three-point element fringe pattern 440 from the z ₁ depth to x. , Shift in the y direction by −x1, y1. In the case of the composite image 660 with respect to the z ₂ depth plane, since the reference point light source D is located at (x ₁ , −y ₁ , z ₁ ), the hologram calculator 260 generates the three-point element fringe pattern 440 from the z ₂ depth. Shift in the x and y directions by x ₁ and −y ₁ .

  Subsequently, the hologram calculation unit 260 combines the n-point element fringe pattern as indicated by reference numeral 670 in FIG. 6 to calculate CGH. In addition, the hologram calculation unit 260 calculates the hologram information 680 as represented by the general formula (9) using CGH.

  Hereinafter, a hologram calculation method using a lookup table and spatial redundancy will be described with reference to FIG. Here, for the sake of clarity, each functional unit constituting the hologram calculation apparatus will be referred to as a “hologram calculation apparatus”. Hereinafter, in the hologram calculation process, portions overlapping with the description of the hologram calculation apparatus are omitted for the sake of clear description of the invention.

FIG. 7 is a diagram illustrating a hologram calculation process according to an embodiment of the present invention.
In step 710, the hologram calculation apparatus calculates a reference element fringe pattern with reference to the input image. The reference element fringe pattern is an element fringe pattern stored in the lookup table 250 in the above-described N-LUT method, and is an element fringe pattern with respect to the depth direction of the object.

  In step 720, the hologram calculation apparatus stores the reference element fringe pattern in a lookup table.

  In step 730, the hologram calculation apparatus calculates the identity data of the input image. That is, the hologram calculation apparatus calculates identity data in which adjacent points having the same brightness and depth values are extracted in a lump.

  In step 740, the hologram calculation apparatus calculates an n-point element fringe pattern using the identity data and the reference element fringe pattern.

  In step 750, the hologram calculation apparatus matches the reference element fringe pattern, the identity data, and the n-point element fringe pattern with each point of the target object, calculates CGH, and calculates hologram information using the CGH. Hereinafter, step 750 will be described in detail with reference to FIG.

  FIG. 8 is a diagram illustrating a process of calculating hologram information by matching a reference element fringe pattern and an n-point element fringe pattern according to an embodiment of the present invention.

  In step 810, the hologram calculation apparatus matches a reference element fringe pattern with a point that is not included in the identity data (an adjacent point that does not have the same brightness and depth value). Also, n is set to 1. Here, n is an arbitrary natural number.

  In step 830, the hologram calculation apparatus determines whether there is a continuous point including n or more points in the identity data.

  If there is a continuous point including n or more points, the hologram calculation apparatus increments n by 1 in step 835.

  In step 840, the hologram calculator matches the n-point element fringe pattern with the n-continuous points. Subsequently, the hologram calculation apparatus returns to Step 830.

  If there is no continuous point including n or more points, in step 850, the hologram calculation apparatus calculates hologram information using CGH. The method for calculating a hologram using CGH has been described above with reference to general formula (9).

  In the process of calculating the hologram information described above, the element fringe pattern is matched by determining the order based on the number of consecutive points of the identity data. However, the element fringe pattern can be matched in the order of the coordinates of the target object. . At this time, the n-point element fringe pattern can be stored in the lookup table.

  The hologram calculation apparatus and method described above have the effect of reducing the calculation complexity for hologram calculation. Below, the effect of the hologram calculation apparatus according to an embodiment of the present invention will be described with reference to the table. Table 1 compares the number of calculation points for calculating a hologram by the above-described method.

The 1-point element fringe pattern indicates a method using an existing N-LUT. In this case, a total of 78,726 points must be calculated to calculate the hologram. In contrast, in the case of the 2-point element fringe pattern to the 4-point element fringe pattern, the points are 82.9%, 79.4%, and 78.3%, respectively, compared to the 1-point element fringe pattern. It turns out that it is sufficient to calculate.
Table 2 compares the calculation times of holograms by the above-described methods.

  According to the existing N-LUT method, the average time for calculating one point is 11.76 ms, but when using the 2-point element fringe pattern, the average time for calculating one point is 9.53 ms. It was found that the calculation time was 81% compared with the existing method. It was found that the calculation time was 9.16 ms for 3-points and 9.05 ms for 4-points, which took 77.9% and 77.0% respectively. Therefore, the hologram calculation method according to the embodiment of the present invention has an effect of reducing the calculation complexity as compared with the existing N-LUT method.

  The computer-generated hologram calculation and reproduction method using the look-up table and the spatial redundancy according to the above-described embodiment of the present invention is stored in a recording medium and then linked to a predetermined device, for example, a mobile communication terminal. Can be done. Here, the recording medium may be a magnetic or optical recording medium such as a hard disk, video tape, CD, VCD, DVD, or may be a database of a client or server computer constructed offline or online. Good.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention. In particular, the spatial redundancy analysis can be performed in various ways such as horizontal, vertical, diagonal, and block units. It is also possible to create an n-point element fringe pattern in advance and calculate a hologram. By forming a 1-point element fringe pattern and forming an n-point element fringe pattern when necessary It is also possible to calculate a hologram.

210 Extraction unit 220 Identity analysis unit 230 Fringe calculation unit 240 Point fringe calculation unit 250 Look-up table 260 Hologram calculation unit

Claims (8)

Calculating one reference element fringe pattern for each point separated by the same distance from a reference point on the hologram plane of the target object;
Storing the reference element fringe pattern according to the distance from the reference point to each point of the target object;
Calculating identity data indicating whether each point of the input image and adjacent points are the same;
calculating an n-point element fringe pattern obtained by combining the n reference element fringe patterns;
Matching the n-continuous points grasped from the identity data with the n-point element fringe pattern to calculate hologram information,
The n is a natural number, and a hologram calculation method. The hologram calculation method according to claim 1, wherein the reference element fringe pattern is calculated by the following general formula (8).
(Wherein, p is an arbitrary natural number, T is the distance between the reference element fringe pattern, r _p is the p-th point and (x, y, 0), the value k is obtained by dividing the 2π in lambda, lambda Is the wavelength of light in the air, θ _R is the angle between the reference light and the object light, and _{ｐ p} is the phase value of the object light at the p-th point of the target object.) The hologram pattern calculation method according to claim 1, wherein the n-point element fringe pattern is calculated by the following general formula (10).
(Wherein, T _n is the n-point element fringe pattern.) The hologram calculation method according to claim 1, wherein the hologram information is calculated by the following general formula (3).
(In the formula, I is hologram information, _ap is the intensity value of object light at the p-th point of the target object, and N is the total number of points constituting the target object.) A fringe calculation unit that calculates one reference element fringe pattern for each point of the target object separated from the reference point of the hologram plane by the same distance;
A lookup table that stores the reference element fringe pattern according to the distance from the reference point to each point of the target object;
An identity analyzer that calculates identity data representing whether each point of the input image and adjacent points are the same;
a point fringe calculation unit for calculating an n-point element fringe pattern obtained by combining the n reference element fringe patterns;
A hologram calculation unit that calculates hologram information by matching the n-continuous points obtained from the identity data and the n-point element fringe pattern,
The n is a natural number. The hologram calculation apparatus according to claim 5, wherein the reference element fringe pattern is calculated by the following general formula (8).
(Wherein, p is an arbitrary natural number, T is the distance between the reference element fringe pattern, r _p is the p-th point and (x, y, 0), the value k is obtained by dividing the 2π in lambda, lambda Is the wavelength of light in the air, θ _R is the angle between the reference light and the object light, and _{ｐ p} is the phase value of the object light at the p-th point of the target object.) 7. The hologram pattern calculation apparatus according to claim 5, wherein the n-point element fringe pattern is calculated by the following general formula (10).
(Wherein, T _n is the n-point element fringe pattern.) The hologram calculation apparatus according to claim 5, wherein the hologram information is calculated by the following general formula (9).
(In the formula, I is hologram information, _ap is the intensity value of object light at the p-th point of the target object, and N is the total number of points constituting the target object.)