KR101233350B1 - hologram transcoding apparatus and the method thereof - Google Patents

Abstract

The present invention can be restored without distortion in the desired three-dimensional space even when the wavelength of the reference light used in the hologram recording process and the pixel spacing of the recording medium differ from the wavelength of the reference light used in the restoration process and the pixel spacing of the spatial light modulator. A holographic transcoding apparatus and method for converting holograms.
According to an aspect of the present invention, there is provided a hologram transcoding apparatus comprising: a pixel interval resampling unit for resampling a digital hologram obtained using a first light source at pixel intervals of a spatial light modulator; A Fourier transform unit for Fourier transforming the hologram resampled by the pixel interval resampling unit; An inverse Fourier transform of the hologram resampled by the wavelength resampling unit and the wavelength resampling unit for resampling the hologram converted into the spatial frequency region by the Fourier transform unit by the wavelength of the second light source having a wavelength different from that of the first light source Thereby including an inverse Fourier transform unit that generates a hologram that can be restored by the second light source.

Description

Hologram transcoding apparatus and method

The present invention relates to an apparatus and method for hologram transcoding, in particular, even when the wavelength of the reference light used in the digital hologram recording process and the pixel spacing of the recording medium are different from the wavelength of the reference light to be used in the restoration process and the pixel spacing of the spatial light modulator. A holographic transcoding apparatus and method for transforming holograms to be restored without distortion in dimensional space.

As is well known, holograms are created using the principles of holography and refer to a fringe pattern (Fringe Pattern) that reproduces a three-dimensional image or a medium on which such interference fringe is recorded. The principle of holography is to split a coherent beam, for example a beam from a laser, into two by a beam splitter so that one beam directly illuminates the recording medium and the other beam is directed to the object we want to see. will be. In this case, the light directly shining on the recording medium is called a reference light, and the light shining on the object is called an object light. Since the object light is light reflected from each surface of the object, the phase difference (distance from the object surface to the recording medium) appears differently depending on the object surface. At this time, the unmodified reference light interferes with the object light, and the recording medium in which the interference fringe is stored is called a hologram.

Next, in order to reconstruct the image stored in the hologram, the light ray may be irradiated to the recording medium again, and the reconstructed reference light having the same wavelength and phase as the recording time should be irradiated.

Meanwhile, according to the development of computer technology, it is possible to artificially generate a hologram by a numerical method. Thus, a computer generated hologram (CGH) is optically restored. For example, a method has been developed for directly recording Fresnel holograms on a Charge Coupled Device (CCD), which is now an intermediate process that allows full digital recording and processing of holograms without any photographic recording. . Such digital sampling and mathematical hologram reconstruction are called digital holography.

)는 아래의 수학식 1에서와 같이 물체광과 산란광 사이의 최대 회절각(

)에 의해 결정된다.The photosensitive material used to record the hologram should be able to resolve the interference pattern caused by the superposition of the object light and the reference light scattered from all points of the object. Where the maximum spatial frequency with resolution

Is the maximum diffraction angle between the object light and the scattered light, as shown in Equation 1 below.

Is determined by

)을, 예를 들어 대략 10㎛라 할 때 최대 분해능을 갖는 공간주파수(이하 간단히 '최대 공간주파수'라 한다)는 아래의 수학식 2에 의해 대략 50Lp㎜(Linepair per ㎜) 정도가 된다.Spacing between adjacent pixels on the CCD (

), For example, about 10 μm, the spatial frequency having the maximum resolution (hereinafter, simply referred to as “maximum spatial frequency”) is approximately 50 Lp mm (Linepair per mm) by Equation 2 below.

According to Equation 1 above, the maximum diffraction angle between the reference light and the object light is limited to a very small angle. In this case, the sine function in Equation 1 may be approximated as Equation 3 below.

, 기록 매체인 CCD의 픽셀 간격을

이라 하고, 도 1의 (b)에 도시한 바와 같이 홀로그램을 복원(Display)할 때 공간광변조기(Spatial Light Modulation; SLM), 예를 들어 LCD(Liquid Crystal Display)나 LCoS(Liquid Crystal on Silicon)과 같은 공간광변조기에 의해 3차원 공간상에서 디스플레이(복원)될 때의 참조광의 파장을

라 하고, 공간광변조기의 픽셀 간격을

라 할 때 3차원 공간이 왜곡 없이 복원되기 위해서는

가 되어야 한다.1 is a conceptual diagram illustrating a hologram recording and reconstruction process. As shown in Fig. 1A, the wavelength of the light at the recording side is measured when the hologram for the three-dimensional object O is recorded.

The pixel spacing of the CCD

As shown in FIG. 1B, a spatial light modulator (SLM), for example, a liquid crystal display (LCD) or a liquid crystal on silicon (LCoS), is used to recover a hologram. The wavelength of the reference light when displayed (restored) in three-dimensional space by a spatial light modulator such as

And the pixel spacing of the spatial light modulator

In order to restore 3D space without distortion

Should be

FIG. 2 is a diagram illustrating a process of recording a hologram from a 3D object using infrared light, and FIG. 3 is a diagram illustrating a process of restoring the hologram shown in FIG. 2 on a 3D space using visible light. It is also. As shown in FIG. 2, in the process of recording the hologram of the three-dimensional object using the infrared light on the CCD, even if no distortion occurs, the hologram recorded in the three-dimensional space using the visible light has no effect. In the case of not performing the correction, since the physical parameters used in the recording process and the restoration process are different, as shown in Fig. 3, the length increases while the height decreases, so that distortion occurs.

That is, all information corresponding to the original three-dimensional object comes from the diffraction angle. In order to maintain the diffraction angle information, the spatial frequency must be modified according to the wavelength. However, due to the difference in wavelength and pixel spacing, the diffraction angle of the infrared hologram becomes much larger than that of visible light. Therefore, in the optical reconstruction of the hologram, the height of the three-dimensional space is shrunk, while the depth thereof is expanded, thereby causing distortion of the reconstructed image.

Longitudinal distortion and transverse distortion can be obtained by Equations 4 and 5, respectively.

은 홀로그램 기록 과정에서 물체와 기록 매체, 예를 들어 CCD 사이의 거리를 나타내고,

는 홀로그램 복원 과정에서 공간광변조기와 복원 영상 사이의 거리를 나타낸다.

은 기록 과정에서 기록 매체인 CCD에 촬영된 물체의 크기, 즉 높이를 나타내고,

는 복원 과정에서 복원 영상의 크기, 즉 높이를 나타낸다.In Equations 4 and 5 above,

Represents the distance between the object and the recording medium, for example a CCD, during the hologram recording process,

Denotes the distance between the spatial light modulator and the reconstructed image during the hologram restoration process.

Represents the size, i.e., the height of the object photographed on the CCD as the recording medium in the recording process,

Represents the size, that is, the height of the restored image during the restoration process.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is desirable even if the wavelength of the reference light used in the hologram recording process and the pixel spacing of the recording medium are different from the wavelength of the reference light used in the restoration process and the pixel spacing of the spatial light modulator. An object of the present invention is to provide a hologram transcoding apparatus and method for converting holograms to be restored without distortion in three-dimensional space.

According to an aspect of the present invention, there is provided a hologram transcoding apparatus comprising: a pixel interval resampling unit for resampling a digital hologram obtained using a first light source at pixel intervals of a spatial light modulator; A Fourier transform unit for Fourier transforming the hologram resampled by the pixel interval resampling unit; An inverse Fourier transform of the hologram resampled by the wavelength resampling unit and the wavelength resampling unit for resampling the hologram converted into the spatial frequency region by the Fourier transform unit by the wavelength of the second light source having a wavelength different from that of the first light source Thereby including an inverse Fourier transform unit that generates a hologram that can be restored by the second light source.

A holographic transcoding device according to a second aspect of the present invention includes a Fourier transform unit for Fourier transforming a digital hologram obtained using a first light source; A wavelength resampling unit for resampling the hologram converted into the spatial frequency region by the Fourier transform unit by the wavelength of the second light source having a wavelength different from that of the first light source; And an inverse Fourier transform unit for inverse Fourier transforming the hologram resampled by the wavelength resampling unit and a pixel interval resampling unit for resampling the hologram converted by the inverse Fourier transform unit at pixel intervals of the spatial light modulator.

In the hologram transcoding apparatus according to the second aspect, the pixel spacing of the hologram to be restored using the second light source is smaller than the pixel spacing of the hologram obtained using the first light source.

)과는 다른 파장(

)을 갖는 제2 광원의 파장(

)으로 리샘플링하는 파장 리샘플링부를 포함하여 이루어지되, 상기 파장 리샘플링의 비율은

인 것을 특징으로 한다.The hologram transcoding apparatus according to the third aspect of the present invention is a pixel spacing resampling unit for resampling a digital hologram obtained using a first light source with a pixel spacing of a spatial light modulator to be used for reconstruction, and the resampling by the pixel spacing resampling unit. The hologram is a wavelength of the first light source (

) And a different wavelength (

Wavelength of the second light source with

Including a wavelength resampling unit for resampling, the ratio of the wavelength resampling is

It is characterized by that.

은 1보다 큰 것을 특징으로 한다.The hologram transcoding device according to the third aspect is

Is greater than one.

축 상의 관심 물체 영역을 적절한 간격으로 샘플링하여 복수의 2차원 이산 영상을 생성하는 (a) 단계; 상기 2차원 이산 영상을 상기 디지털 홀로그램 측으로 후방 전파시켜서 상기

축 상의 원하는 레이어에서의 수학적인 복원 영상을 획득하는 (b) 단계 및 상기 각 샘플링 간격에서 상기 후방 전파를 통해 얻어진 복원 영상을 모두 중첩함으로써 관심 물체 영역에서의 3차원 영상을 복원할 수 있는 가시광 홀로그램을 생성하는 (c) 단계를 포함하여 이루어지되, 상기 2차원 이산 영상은 상기 제1 광원의 파장과 홀로그램의 픽셀 간격을 사용하여 생성되고, 상기 복원 영상은 복원 시 사용될 제2 광원의 파장(≠제1 광원의 파장)과 공간광변조기의 픽셀 간격을 사용하여 생성된다.According to another aspect of the present invention, a hologram transcoding method includes a digital hologram obtained by using a first light source and mathematically reconstructing an image obtained by using the first light source.

(A) sampling a region of interest on the axis at appropriate intervals to generate a plurality of two-dimensional discrete images; Propagating the two-dimensional discrete image backward to the digital hologram

(B) acquiring a mathematically reconstructed image in a desired layer on an axis, and a visible light hologram capable of reconstructing a three-dimensional image in the object region of interest by superimposing all reconstructed images obtained through the back propagation at each sampling interval. And (c) generating an image, wherein the two-dimensional discrete image is generated using the wavelength of the first light source and the pixel spacing of the hologram, and the reconstructed image is a wavelength of the second light source to be used for restoration. The wavelength of the first light source) and the pixel spacing of the spatial light modulator.

According to the hologram transcoding apparatus and method of the present invention, even if the wavelength of the reference light used in the hologram recording process and the pixel spacing of the recording medium are different from the wavelength of the reference light used in the restoration process and the pixel spacing of the spatial light modulator, It is possible to restore without distortion in space.

1 is a conceptual diagram illustrating a hologram recording and restoration process.
2 is a view for explaining a process of recording a hologram from a three-dimensional object using infrared light.
3 is a view for explaining a process of restoring the hologram shown in FIG. 2 on a three-dimensional space using visible light;
Figure 4 is a block diagram of an embodiment of a holographic transcoding device of the present invention.
Figure 5 is a block diagram according to another embodiment of the hologram transcoding apparatus of the present invention.
6 illustrates a visible light hologram with distortion corrected according to the embodiment of FIG. 5;
7 and 8 are diagrams for explaining a transcoding conversion method according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the hologram transcoding apparatus and method of the present invention.

Table 1 below is an exemplary table showing various physical parameters on the recording side and the restoration side and the relationship between them.

Pixel spacing Spatial frequency wavelength Diffraction angle Object distance Object size Record side

Restoration side

가 된다. 여기에서,

은 기록측, 즉 CCD의 픽셀 간격이고,

는 복원측, 즉 공간광변조기인 LCD나 LCoS의 픽셀 간격인데, 본 실시예에서와 같이,

가

보다 작은 경우에는 업샘플링이 되는 반면에 큰 경우에는 다운샘플링될 것이다.4 is a block diagram illustrating a hologram transcoding apparatus according to an embodiment of the present invention, which illustrates the use of infrared light for hologram recording and visible light for reconstruction. As shown in FIG. 4, first, the pixel spacing resample unit 20 resamples the digital hologram 10 obtained by using infrared light at the pixel spacing of the spatial light modulator. In this case, a magnification ratio is shown. Is

. From here,

Is the pixel spacing of the recording side, i.e., the CCD,

Is the pixel spacing of the restoration side, i.e. LCD or LCoS, which is a spatial light modulator.

end

Smaller ones will be upsampled while larger ones will be downsampled.

)을 갖는 가시광 홀로그램으로 만들어주기 위해 주파수 영역에서 재차 리샘플링을 수행, 즉

로 리샘플링함으로써 스펙트럼의 분포를 변화시킨다.Next, the Fourier transform unit 30 transforms the resampled hologram into Fourier transform and transforms it into a spatial frequency region, thereby creating a dispersion pattern that is dependent on the diffraction angle, that is, the diffraction angle. Next, the wavelength resample unit 40 obtains the hologram converted into the spatial frequency domain in such a manner that a desired diffraction angle (

Resampling again in the frequency domain to produce a visible light hologram with

By resampling to change the distribution of the spectrum.

Finally, the inverse Fourier transform unit 50 generates the visible light hologram 60 that can be restored without distortion by inverse Fourier transforming the resampled visible light hologram.

가

보다 큰 경우에는 다운샘플링이 되어 정보가 손실되기 때문에 문제가 발생하지만

가

보다 작은 경우에는 업샘플링이 되어 정보의 손실이 없기 때문에 푸리에 변환부와 파장 리샘플부를 전단에 두어 적외광 홀로그램을 공간주파수 영역으로 변환시킨 상태에서 파장 리샘플링을 수행하고, 파장 리샘플부의 후단에 역푸리에 변환부와 픽셀간격 리샘플부를 두어 인버스 푸리에 변환과 픽셀간격 리샘플링을 순차적으로 수행해도 왜곡 없는 3차원 영상을 복원할 수 있다.From here,

end

If it is larger, the problem occurs because it is downsampled and information is lost.

end

If smaller, upsampling results in no loss of information, so the Fourier transform section and the wavelength resample section are placed at the front end to perform wavelength resampling while converting the infrared hologram into the spatial frequency domain. The inverse Fourier transform and the pixel interval resampling may be sequentially provided by the Fourier transform unit and the pixel spacing resampler to restore a 3D image without distortion.

가 된다. 여기에서,

은 기록측, 즉 CCD의 픽셀 간격이고,

는 복원측, 즉 공간광변조기인 LCD나 LCoS의 픽셀 간격인데, 본 실시예에서와 같이,

가

보다 작은 경우에는 업샘플링이 되는 반면에 큰 경우에는 다운샘플링될 것이다.FIG. 5 is a block diagram according to another embodiment of the hologram transcoding apparatus of the present invention, which exemplarily reduces the amount of computation by omitting the Fourier transform unit and the inverse Fourier transform unit in FIG. 4. FIG. 6 illustrates a visible light hologram in which distortion is corrected according to the exemplary embodiment of FIG. 5. First, according to the present embodiment as shown in FIG. 5, first, the pixel interval resample unit 20 resamples the digital hologram 10 obtained by using infrared light. In this case, the magnification ratio is As in the case of Figure 4

. From here,

Is the pixel spacing of the recording side, i.e., the CCD,

Is the pixel spacing of the restoration side, i.e., LCD or LCoS, which is a spatial light modulator, as in this embodiment,

end

Smaller ones will be upsampled while larger ones will be downsampled.

의 비율로서 리샘플링하여 최종적으로 원하는 가시광 홀로그램(60′)을 생성한다.Next, in this embodiment, the wavelength resample unit 40 immediately resamples the wavelength without performing Fourier transform. Unlike the case of FIG.

Resampling as a ratio yields the desired visible light hologram 60 '.

에 대한 공간주파수

가

에 대한 공간주파수

보다 큰 상태에서 푸리에 변환을 행함이 없이 바로 파장에 대한 리샘플링을 수행하기 때문에

가 작고

이 크면

가 1보다 작은 값을 갖는데,

이 1보다 작은 값을 갖는다는 것은 복원에 사용될 홀로그램의 사이즈가 줄어든다는 것을 의미하고, 따라서 이를 3차원 공간상에서 복원함에 있어서는 도 6에 도시한 바와 같이 관심 물체 영역을 복원 영상에 대한 높이를 충족시키는 거리까지 이동시켜야 한다. 반면에

이 1보다 클 경우, 즉 업샘플링의 경우에는 완전한 해상도를 얻을 수 있기 때문에 푸리에 변환과 인버스 푸리에 변환을 거치지 않더라도 원하는 3차원 공간에 풀 해상도의 영상을 복원시킬 수가 있다.According to this embodiment,

Spatial frequency for

end

Spatial frequency for

Because resampling is performed directly on the wavelength without performing Fourier transform

Is small

Is big

Has a value less than 1,

Having a value smaller than 1 means that the size of the hologram to be used for the restoration is reduced, and therefore, in restoring it in three-dimensional space, as shown in FIG. You must move to the street. On the other hand

If it is larger than 1, that is, in the case of upsampling, the full resolution can be obtained, and the full resolution image can be reconstructed in the desired three-dimensional space without performing the Fourier transform and the Inverse Fourier transform.

Tables 2 and 3 below are exemplary tables showing various physical parameters at the time of recording and restoring, respectively.

Pixel spacing Spatial frequency wavelength Diffraction angle Object distance Object size Record side 25 μm 2,000 Lpm 10.6㎛ 12.24 ㅀ 300 mm 880 mm Magnification

0.05

20

0.05

300 mm 880 mm Restoration side 1.25 μm 40,000Lpm 0.532 μm 12.24 ㅀ 300 mm 880 mm

Pixel spacing Spatial frequency wavelength Diffraction angle Object distance Object size Record side 25 μm 2,000 Lpm 10.6㎛ 12.24 ㅀ 300 mm 880 mm Magnification

0.32

3.125

0.05

0.156

0.32

2.048

Restoration side 8㎛ 6,250Lpm 0.532 μm 1.9 ㅀ 96 mm 1,800 mm

이 10.6㎛, 그 최대 회절각이 12.24°, CCD의 픽셀 간격이 25㎛인 경우에

가 0.532㎛이기 때문에 가시광을 사용하여 적외광으로 기록된 홀로그램을 복원하기 위해서는 LCD나 LCoS의 픽셀 간격이 1.25㎛가 되어야 하는데, 이 정도의 픽셀 간격은 현재의 기술로는 구현할 수가 없다.In case of using infrared light for hologram recording and visible light for restoration, as shown in Table 2,

Is 10.6 µm, the maximum diffraction angle is 12.24 °, and the pixel spacing of the CCD is 25 µm.

Is 0.532µm, the pixel spacing of LCD or LCoS should be 1.25µm in order to recover the hologram recorded with infrared light using visible light. This pixel spacing cannot be realized by current technology.

이 10.6㎛, 최대 회절각이 12.24°, CCD의 픽셀 간격이 25㎛이고

가 0.532㎛인 경우에 현 수준에서 가장 낮은 8㎛의 픽셀 간격을 갖는 LCD나 LCoS를 사용하게 되면, 회절각이 1.9°밖에 되지 않기 때문에 도 6에 도시한 바와 같이 LCD나 LCoS로부터 복원 영상까지의 거리를, 기록시 CCD와 물체까지의 거리(

)보다 2.048배만큼 이동시켜야 비로소 기록된 물체의 크기(

)보다 0.32배 작은 복원 영상을 구현할 수가 있다. 이와 같이 본 실시예는 적외광 대 가시광 같이 파장 차이가 너무 큰 경우에 사용하기에는 무리가 따르며, 적색광이나 청색광 대 녹생광과 같이 파장 차이가 크지 않는 경우에 바람직하게 적용될 수 있을 것이다. 본 실시예에서도 전술한 실시예와 마찬가지로 업샘플링이 되는 한 파장 리샘플링을 먼저 수행한 후에 픽셀간격 리샘플링을 수행할 수도 있을 것이다.On the other hand, as shown in Table 3

10.6 µm, the maximum diffraction angle is 12.24 °, and the pixel spacing of the CCD is 25 µm.

Is 0.532 μm, when using the LCD or LCoS having the lowest pixel spacing of 8 μm at the current level, since the diffraction angle is only 1.9 °, as shown in FIG. The distance between the CCD and the object

Must be 2.048 times larger than

It is possible to realize a reconstructed image 0.32 times smaller than). As such, the present embodiment is difficult to use when the wavelength difference is too large, such as infrared light and visible light, and may be preferably applied when the wavelength difference is not large, such as red light or blue light versus green light. In the present exemplary embodiment, the wavelength resampling may be performed first, and then the pixel interval resampling may be performed as long as upsampling is performed.

7 and 8 illustrate a transcoding transform method according to another embodiment of the present invention.

가 너무 작아지게 되는데, 이 경우에는 푸리에 변환을 행하지 않고서는 현재의 픽셀 간격을 갖는 공간광변조기로는 구현이 어렵다. 이를 감안하여 본 실시예에서는 도 7에 도시한 바와 같이 적외광으로 기록된 홀로그램을 적외광을 사용하여 수학적으로 복원한 영상의

축 상의 관심 물체 영역을 적절한 간격으로 샘플링하여 복수의 2차원 이산 영상을 만든다. 이 경우에 예를 들어, 망원 카메라의 줌 배율을 높이면 어떤 영역은 포커싱이 이루어지나 나머지 영역은 디포커싱되는 것과 같이 현재 샘플링된 이산 영상을 제외한 나머지 부분은 블러링(blurring) 영상으로 된다.As described above, for example, the wavelength is 10.6 mu m in the case of infrared light and 0.533 mu m in the case of visible light. Thus, if the difference between the wavelength of the light used at the time of recording and the wavelength used at the time of restoration is too large,

Becomes too small, in which case it is difficult to implement with a spatial light modulator having the current pixel spacing without performing Fourier transform. In view of this, in the present embodiment, as shown in FIG. 7, a hologram recorded with infrared light is mathematically reconstructed using infrared light.

Sample the region of interest on the axis at appropriate intervals to produce a plurality of two-dimensional discrete images. In this case, for example, when the zoom magnification of the telephoto camera is increased, a portion of the image except for the currently sampled discrete image is a blurring image, such that a certain area is focused but the remaining area is defocused.

축 상의 관심 물체 영역을 소정의 샘플링 간격으로 이산화시킨 2차원 영상을 수학적인 방법을 사용하여 다시 적외광 홀로그램 측으로 후방 전파(back propagation)시키면 원하는 깊이, 즉

축 상의 원하는 레이어에서의 수학적인 복원 영상을 획득할 수가 있다. 이 경우에 물론 디포커싱된 부분에서는 블러링 현상이 발생하지만 샘플링 간격을 적절하게 설정하면 2차원의 복수의 이산 영상을 연속적인 3차원 영상으로 인지하게 된다.On the other hand, since the hologram is encoded in two dimensions rather than in three dimensions, the hologram is also two-dimensionally decoded. therefore

The back propagation of a two-dimensional image discretizing the region of interest on the axis at a predetermined sampling interval back to the infrared hologram side using a mathematical method, results in a desired depth,

A mathematical reconstruction image of a desired layer on the axis can be obtained. In this case, of course, blurring occurs in the defocused part. However, if the sampling interval is set appropriately, a plurality of two-dimensional discrete images are recognized as continuous three-dimensional images.

Here, the mathematically reconstructed image from the infrared hologram is reconstructed using the physical parameters used in the infrared hologram recording, that is, the wavelength of the infrared light and the pixel spacing of the CCD, while the reconstructed image obtained by the back propagation is The physical parameters to be used, i.e. the wavelength of visible light and the pixel spacing of LCD or LCoS, are reconstructed so that the mathematically reconstructed image from the infrared hologram and the reconstructed image obtained by back propagation differ in the pattern itself.

As described above, in the present exemplary embodiment, a visible light hologram capable of reconstructing the 3D image in the object region of interest may be generated by superimposing all the reconstructed images obtained through the rear wave propagation at each sampling interval.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the technical idea of the present invention.

10: infrared hologram, 20: pixel interval resample section,
30: Fourier transform unit, 40: wavelength resample unit,
50: inverse Fourier transform unit, 60, 60 ': visible light hologram

Claims (6)

A pixel interval resampling unit for resampling the digital hologram obtained using the first light source with the pixel interval of the spatial light modulator;
A Fourier transform unit for Fourier transforming the hologram resampled by the pixel interval resampling unit;
A wavelength resampling unit for resampling the hologram converted into the spatial frequency region by the Fourier transform unit by the wavelength of the second light source having a wavelength different from that of the first light source;
And an inverse Fourier transform unit for generating a hologram that can be restored by the second light source by inverse Fourier transforming the hologram resampled by the wavelength resampling unit. A Fourier transform unit for Fourier transforming the digital hologram obtained using the first light source;
A wavelength resampling unit for resampling the hologram converted into the spatial frequency region by the Fourier transform unit by the wavelength of the second light source having a wavelength different from that of the first light source;
An inverse Fourier transform unit for inverse Fourier transforming the resampled hologram by the wavelength resampling unit;
And a pixel interval resampling unit for resampling the hologram converted by the inverse Fourier transform unit at pixel intervals of the spatial light modulator. The method of claim 2,
And the pixel spacing of the hologram to be reconstructed using the second light source is smaller than the pixel spacing of the hologram obtained using the first light source. A pixel spacing resampling unit for resampling the digital hologram obtained using the first light source with the pixel spacing of the spatial light modulator to be used for restoration;
The hologram resampled by the pixel spacing resampling unit has a wavelength of the first light source (

Wavelength of the second light source having a wavelength different from

Including a wavelength resampling unit to resample to,
The wavelength resampling unit

Hologram transcoding device, characterized in that for resampling as the ratio of. The method of claim 4, wherein
remind

Hologram transcoding device, characterized in that greater than one. The digital hologram obtained using the first light source is mathematically reconstructed using the first light source.

(A) sampling a region of interest on the axis to generate a plurality of two-dimensional discrete images;
Propagating the two-dimensional discrete image backward to the digital hologram

(B) obtaining a mathematical reconstructed image in the layer on the axis, and
(C) generating a visible light hologram capable of reconstructing a three-dimensional image in the object region of interest by overlapping the reconstructed image obtained through the rearward wave at each interval sampled in the step (a),
The two-dimensional discrete image is generated using the wavelength of the first light source and the pixel spacing of the hologram, and the reconstructed image is a wavelength and spatial light of a second light source having a wavelength different from that of the first light source to be used for restoration. Hologram transcoding method generated using the pixel spacing of a modulator.

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