KR20150076526A - APPARATUS AND METHOD FOR PRODUCING 3-Dimension HOLOGRAM IMAGE - Google Patents

Abstract

A method for producing a three-dimension (3D) hologram image according to the present invention comprises the steps of: calculating the size of elemental fringe patterns according to depths in a depth map received from a system; using the size of elemental fringe patterns to detect noise pixels; generating a playback depth map by removing the noise pixels from the depth map; and generating a 3D hologram image using the playback depth image, thereby obtaining a clear 3D hologram image.

Description

TECHNICAL FIELD [0001] The present invention relates to a 3D hologram generating apparatus and a 3D hologram generating apparatus.

The present invention relates to a 3D hologram generating apparatus and a 3D hologram generating method, and more particularly, to a 3D hologram generating apparatus and a 3D hologram generating method capable of obtaining a clear hologram image by noise removal of a depth map.

In recent years, studies on three-dimensional (3D) image and image reproduction technology have been actively conducted. Stereoscopic media is expected to lead the next generation imaging device as a new realistic image media that elevates the level of visual information to a new level. The conventional 2D image system provides the plane image, but the 3D image system is the ultimate image realization technology in terms of showing the actual image information of the object to the observer.

Among the methods for reproducing stereoscopic images, the holography method is a method in which a stereoscopic image identical to a real object can be sensed without attaching special glasses when observing a holography produced using a laser. Therefore, the holographic method has excellent stereoscopic effect and is known to be the ideal method for observers to feel stereoscopic images without fatigue.

The holographic system uses the principle of recording and reproducing an interference signal obtained by superimposing light (object wave) reflected from an object and light (reference wave) having coherence. A hologram is a technique in which an interference fringe formed by causing an object wave scattered by an object to collide with a reference wave incident from another direction is recorded on a scattered film using a highly coherent laser beam. When an object wave and a reference wave meet, an interference fringe due to interference is formed. The amplitude and phase information of the object are also recorded in this fringe pattern. Holography refers to irradiating the recorded interference fringe with reference light and restoring the stereoscopic effect recorded in the hologram into a stereoscopic image.

A computer generated hologram (CGH) has been developed as a method for computer generated holograms for storage, transmission and image processing.

A computer generated hologram (CGH) generates a hologram interference pattern data by calculating an interference pattern between an object light and a reference light using a computer, and transmits the generated hologram interference pattern data to a spatial light modulator (SLM) The stereoscopic image corresponding to the hologram interference pattern realized in the spatial light modulator is restored and reproduced by irradiating reference light using a laser to the spatial light modulator SLM.

In recent years, a sub hologram (CGH) method has been applied to generate a high-speed digital hologram by generating a hologram image only in a region of interest of a user when generating a computer generated hologram (CGH). At this time, the computer generated hologram (CGH) shows one pattern by superimposing the element fringe patterns representing the respective points based on the depth map, which is three-dimensional image information, and applies the sub hologram method The size of the element fringe pattern according to the depth is changed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a reverse direction of a noise pixel and an image pixel upon superposition of an element fringe pattern. FIG.

As can be seen from FIG. 1, if the size of the element fringe pattern of the noise pixel is larger than that of the image pixel, information of adjacent image pixels is lost. This affects the hologram reconstruction image and requires the removal of noise from the depth map before computer generated hologram (CGH) generation.

That is, the 3D hologram generating method of the related art has a problem that the element fringe pattern of the noise pixel covers the element fringe pattern of the image pixel in the process of generating the computer generated hologram of the sub hologram system due to the noise of the depth map, have.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a 3D hologram generating device and a 3D hologram generating method capable of removing noise from a depth map before generation of a computer generated hologram (CGH) have.

In order to accomplish the above object, the present invention provides a method of detecting a depth map, comprising the steps of: calculating a size of an element fringe pattern according to a depth in a depth map received from a system; detecting a noise pixel using the size of the element fringe pattern; Generating a reproduction depth map from which the noise pixels have been removed, and generating a hologram using the reproduction depth map.

The present invention also relates to an image processing apparatus including an element fringe pattern size calculating unit for calculating a size of an element fringe pattern according to a depth in a depth map received from a system, a noise pixel detecting unit detecting a noise pixel using the size of the element fringe pattern, And a hologram generating unit for generating a hologram using the reproduction depth map, and a hologram generating unit for generating a hologram using the reproduction depth map.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

According to the present invention as described above, the following effects can be obtained.

The present invention compares the size of the element fringe pattern of the noise pixel with the adjacent image pixels before generating the computer generated hologram (CGH) to detect the element fringe pattern of adjacent noise pixels larger than the size of the element fringe pattern of the image pixel, By removing the element fringe pattern of the noise pixel from the depth map, a clear holographic image can be obtained.

In addition, other features and advantages of the present invention may be newly understood through embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram showing the reverse orientation of a noise pixel and an image pixel upon superposition of an element fringe pattern.
2 is a block diagram showing a detailed configuration of a 3D hologram generating device.
Fig. 3 is a diagram showing that the element fringe pattern varies in size according to depth; Fig.
Figure 4 illustrates a method for calculating the size of an element fringe pattern according to an embodiment of the present invention.
5 is a diagram illustrating a process of superimposing an element fringe pattern on the basis of a depth map;
FIG. 6 is a flowchart illustrating a process of generating a 3D hologram in the 3D hologram generating apparatus of FIG. 2. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing the detailed configuration of the 3D hologram generating device.

2, a 3D (Dimension) hologram generating apparatus 100 includes an element fringe pattern size calculating unit 101, a noise pixel detecting unit 102, a noise removing unit 103, and a hologram generating unit 104 .

The element fringe pattern size calculating unit 101 may calculate a size of an element fringe pattern according to a depth of a depth map.

Here, the depth map is a map showing a three-dimensional distance difference between objects in an image, and the pixels included in the depth map may be represented by a gray level, Lt; / RTI > At this time, the higher value (255), that is, the closer to white, indicates the closer to the viewer window and the lower the value (0), that is, the closer to black the viewer window (View Window)

FIG. 3 is a diagram showing that the element fringe pattern varies in size according to the depth. FIG.

Referring to FIG. 3, the element fringe pattern 200 for each point changes its size according to the depth. As the element fringe pattern 200 becomes closer to the spatial light modulator 300 (SLM), the size of the element fringe pattern 200 becomes smaller The larger the distance, the larger.

Computer generated holograms represent a pattern through superposition of the element fringe patterns calculated for each object point. That is, the element fringe pattern varies in size depending on the depth, which can be an important factor in restoring the hologram image.

4 is a diagram illustrating a method for calculating the size of an element fringe pattern according to an embodiment of the present invention.

_{Here, (slm x1, slm y1,} slm z) and _{(slm x2, slm y2, slm} z) is a component coordinate on slm (300, spatial light modulators) of the fringe pattern _{(200), (holo x,} holo y, holo _z) are the coordinates of the object point (400), (view _{x1, y1} view, view _z) and (view _{x2, y2} view, view _z) represents the coordinates of the viewer 500. the

At this time, the size of the element fringe pattern 200 can be calculated by the following equation.

,

,

,

와 같이 계산될 수 있다.First, the size of the element fringe pattern in the X direction is calculated as follows: slm _x2 -slm _x1 , size of the element fringe pattern in the Y direction = slm _y2 -slm _y1, and the coordinates of the element fringe pattern 200 on the slm (300)

,

,

,

Can be calculated as follows.

Referring again to FIG. 2, the noise pixel detector 102 compares the size of the element fringe pattern according to the depth calculated by the element fringe pattern size calculator 101, and detects noise pixels acting as noise in adjacent pixels can do.

Hereinafter, a process of generating noise in the boundary region between the image region and the noise region will be described with reference to FIG.

5 is a diagram illustrating a process of superimposing an element fringe pattern on the basis of a depth map.

Referring to FIG. 5, a depth map of a bicycle image is displayed, and when the handle portion of the bicycle image is enlarged, a depth map of the bicycle image may not be displayed clearly by unwanted noise pixels.

The element fringe pattern size calculating unit 101 according to the embodiment of the present invention divides the depth map into the image area 10a and the noise area 10b and then the image area 10a and the noise area 10b The size of the element fringe pattern along the depth can be calculated.

That is, the image area 10a is an area where an image of an object is formed, and the noise area 10b is a background area rather than an image of an object. At this time, noise occurs in the boundary region between the image region 10a and the noise region 10b.

More specifically, in an area where the element fringe pattern of the noise area 10b is larger than the element fringe pattern of the adjacent image area 10a, the element fringing pattern of the noise pixel covers the element fringing pattern of the image pixel, Which may degrade the quality of the hologram image.

In order to solve such a problem, the 3D hologram generating apparatus according to the embodiment of the present invention compares the element fringe pattern sizes of the adjacent image region 10a and the noise region 10b, It is possible to detect an element fringe pattern of adjacent noise pixels larger than the size.

Referring again to FIG. 2, the noise removing unit 103 may remove the noise pixels detected by the noise detecting unit 102 in the depth map.

Specifically, the noise removing unit 103 processes the gray of the noise pixel detected by the noise detecting unit 102 to 0, that is, a black background in a depth map of an image of a desired object, You can create a map.

The hologram generating unit 104 may generate a 3D hologram based on the depth map filtered by the noise removing unit 103. [

The hologram generating unit 104 includes a calculation method based on a ray tracing method for calculating the diffraction of light based on the depth map filtered by the noise removing unit 103, a look-up table ), A method using fast Fourier transform, or the like, to generate a 3D hologram. In addition, the apparatus for generating a 3D hologram according to an embodiment of the present invention may use a sub hologram system in which a viewing angle is limited, instead of a general hologram system having a large viewing angle.

Computer generated hologram (CGH) is used for 3D hologram image acquisition. The core of the present invention is not limited to the generation of a computer generated hologram (CGH), and thus a detailed description thereof will be omitted.

As described above, the 3D hologram generating apparatus according to the embodiment of the present invention compares the size of the element fringe pattern of the noise pixel 10b with that of the adjacent image pixel 10a before generation of the computer generated hologram CGH, A sharp hologram image can be obtained by detecting an element fringing pattern of an adjacent noise pixel 10b larger than the size of the element fringe pattern of the detected noise pixel 10b and removing the element fringing pattern of the detected noise pixel 10b from the depth map.

FIG. 6 is a flowchart illustrating a process of generating a 3D hologram in the 3D hologram generating apparatus of FIG. 2. Referring to FIG.

First, in step S601, the 3D hologram generating apparatus 100 can calculate the size of the element fringe pattern according to the depth of the depth map.

At this time, the size of the element fringe pattern 200 can be calculated by the following equation.

,

,

,

와 같이 계산될 수 있다.First, the size of the element fringe pattern in the X direction is calculated as follows: slm _x2 -slm _x1 , size of the element fringe pattern in the Y direction = slm _y2 -slm _y1, and the coordinates of the element fringe pattern 200 on the slm (300)

,

,

,

Can be calculated as follows.

_{Here, (slm x1, slm y1,} slm z) and _{(slm x2, slm y2, slm} z) is a component coordinate on slm (300, spatial light modulators) of the fringe pattern _{(200), (holo x,} holo y, holo _z) are the coordinates of the object point (400), (view _{x1, y1} view, view _z) and (view _{x2, y2} view, view _z) represents the coordinates of the viewer 500. the

Then, in step S602, the 3D hologram generating apparatus 100 may detect a noise pixel acting as a noise in adjacent pixels by comparing the size of the element fringe pattern according to the depth.

For example, the 3D hologram generating device 100 may compare the sizes of the element fringe patterns of adjacent image areas and noise areas to detect an element fringe pattern of adjacent noise pixels larger than the size of the element fringe pattern of the image pixels .

Next, in step S603, the noise pixel detected in the depth map can be removed.

As an example, a filtered depth map can be generated by processing the gray of the detected noise pixel in the depth map for the image of the desired object to zero, i.e., a black background.

In step S604, the 3D hologram may be generated based on the filtered depth map. At this time, a computer generated hologram (CGH) is used to acquire a 3D holographic image.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. Will be apparent to those of ordinary skill in the art.

100: 3D hologram generating apparatus 101: Element fringe pattern size calculating unit
102: Noise pixel detection unit 103: Noise removal unit
104: hologram generating unit 200: element fringe pattern
300: spatial light modulator 400: object point
500: viewers

Claims (10)

Calculating a size of an element fringe pattern according to depth in a depth map received from the system;
Detecting a noise pixel using the size of the element fringe pattern;
Generating a reproduction depth map from which the noise pixels have been removed from the depth map; And
And generating a hologram using the reproduction depth map. The method according to claim 1,
Wherein the size of the element fringe pattern is calculated by the following equation.
1. Size of element fringe pattern in X direction ≡ slm _x2 - slm _x1
2. Size of element fringe pattern in Y direction ≡ slm _y2 - slm _y1
Where slm _x1 is the x1 coordinate of the element fringe pattern on slm (spatial light modulator), slm _x2 is the x2 coordinate of the element fringe pattern on slm (spatial light modulator), slm _y1 is the element fringe pattern on slm (spatial light modulator) y1 coordinate, slm _y2 is the y2 coordinate of the element fringe pattern on slm (spatial light modulator). 3. The method of claim 2,
and the coordinates of the element fringe pattern on the slm (spatial light modulator) are calculated by the following equation.
One.

2.

3.

4.

_{Here, (slm x1, slm y1,} slm z) and _{(slm x2, slm y2, slm} z) are the coordinates on the element fringe pattern slm (spatial light _{modulator), (holo x, holo y} , holo z) is the object point (View _x1 , view _y1 , view _z ) and (view _x2 , view _y2 , view _z ) are the coordinates of the viewer. The method according to claim 1,
Wherein the step of calculating the element fringe pattern size comprises:
Wherein the depth map is divided into an image area and a noise area, and a size of an element fringe pattern is calculated according to a depth in a boundary area between the image area and the noise area. 5. The method of claim 4,
Wherein the step of detecting the noise pixel comprises:
Wherein the size of the element fringe pattern of the noise region is larger than the size of the element fringe pattern of the image region by comparing sizes of the element fringe patterns of the adjacent image region and the noise region. An element fringe pattern size calculator for calculating a size of an element fringe pattern according to a depth in a depth map received from the system;
A noise pixel detector for detecting a noise pixel using the size of the element fringe pattern;
A noise removing unit for generating a reproduction depth map in which the noise pixels are removed from the depth map; And
And a hologram generating unit for generating a hologram using the reproduction depth map. The method according to claim 6,
Wherein the size of the element fringe pattern is calculated by the following equation.
1. Size of element fringe pattern in X direction ≡ slm _x2 - slm _x1
2. Size of element fringe pattern in Y direction ≡ slm _y2 - slm _y1
Where slm _x1 is the x1 coordinate of the element fringe pattern on slm (spatial light modulator), slm _x2 is the x2 coordinate of the element fringe pattern on slm (spatial light modulator), slm _y1 is the element fringe pattern on slm (spatial light modulator) y1 coordinate, slm _y2 is the y2 coordinate of the element fringe pattern on slm (spatial light modulator). The method according to claim 6,
and the coordinates of the element fringe pattern on the slm (spatial light modulator) are calculated by the following equation.
One.

2.

3.

4.

_{Here, (slm x1, slm y1,} slm z) and _{(slm x2, slm y2, slm} z) are the coordinates on the element fringe pattern slm (spatial light _{modulator), (holo x, holo y} , holo z) is the object point (View _x1 , view _y1 , view _z ) and (view _x2 , view _y2 , view _z ) are the coordinates of the viewer. 9. The method of claim 8,
Wherein the element fringe pattern size calculating unit calculates,
Wherein the depth map is divided into an image area and a noise area, and a size of an element fringe pattern is calculated according to a depth in a boundary area between the image area and the noise area. 10. The method of claim 9,
Wherein the noise pixel detecting unit comprises:
Wherein the size of the element fringe pattern of the noise region is larger than the size of the element fringe pattern of the image region by comparing the size of the element fringe pattern of the adjacent image region and the noise region.

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