WO2019225778A1 - Procédé d'affichage holographique en couleurs dans une slm unique basée sur un fdm à l'aide d'un procédé de décalage double - Google Patents

Procédé d'affichage holographique en couleurs dans une slm unique basée sur un fdm à l'aide d'un procédé de décalage double Download PDF

Info

Publication number
WO2019225778A1
WO2019225778A1 PCT/KR2018/005857 KR2018005857W WO2019225778A1 WO 2019225778 A1 WO2019225778 A1 WO 2019225778A1 KR 2018005857 W KR2018005857 W KR 2018005857W WO 2019225778 A1 WO2019225778 A1 WO 2019225778A1
Authority
WO
WIPO (PCT)
Prior art keywords
image
channel
frequency spectrum
shifting
hologram
Prior art date
Application number
PCT/KR2018/005857
Other languages
English (en)
Korean (ko)
Inventor
김은수
임술봉
Original Assignee
광운대학교 산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 광운대학교 산학협력단 filed Critical 광운대학교 산학협력단
Priority to PCT/KR2018/005857 priority Critical patent/WO2019225778A1/fr
Publication of WO2019225778A1 publication Critical patent/WO2019225778A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/02—Details of features involved during the holographic process; Replication of holograms without interference recording
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/22—Processes or apparatus for obtaining an optical image from holograms

Definitions

  • the present invention relates to a full color holographic display method in a single SLM based FDM using a double shifting method. More specifically, the present invention relates to the frequency spectrum position of an RGB channel hologram simultaneously with a simplified image shift and phase shifting process. It is to provide a full color holographic display method in a single SLM based FDM using a dual shifting method that can be directly controlled.
  • Korean Patent Laid-Open Publication No. 10-2013-0099650 discloses a method for generating a hologram using redundancy of a 3D video, wherein the 3D points included in the 3D video frame based on the current 3D video frame and the previous 3D video frame. Generating an update map indicating a three-dimensional point among which updates are required; And modifying the update map to further include information indicating an update for a 3D point associated with a 3D point that requires the update. It is open.
  • Korean Patent Laid-Open Publication No. 10-2013-0096872 discloses a holographic display device for generating a hologram, which includes at least a partial size of a size of a sub-hologram for reconstructing an object point included in a scene reconstructed into the hologram A storage unit for storing one reference table; And calculating a hologram value of sub-holograms for reconstructing each of at least one object point among the object points included in the scene by using the at least one reference table having the partial size, and overlapping the sub-holograms
  • a holographic display device comprising a control unit for generating a hologram is disclosed.
  • a full color hologram display system requires three SLMs separately for the RGB channel since the RGB color holograms must be recorded and reconstructed separately based on the interference and diffraction optics. Therefore, much more SLM is required to reconstruct full color large images using basic spatial multiplexing methods.
  • the time multiplexing method can reduce the SLM to a single SLM or a group of SLM arrays, this method requires a high refresh rate SLM to overcome the flicker effect and complex synchronization system.
  • the present invention has been made to solve the above problems, and a dual shifting method composed of two types of image position correction methods for simplifying the operation of the FDM for implementing a full color holographic display in a single SLM. to provide.
  • This method is the image shift method and phase shift method.
  • the shift invariance of the NLUT method allows simple control of the image position by moving the center position of the precomputed main fringe pattern (PFP).
  • the present invention relates to a full color holographic display method in a single SLM based FDM using a double shifting method, wherein a group of three PFPs with different center offsets has three channel images-shift with the same offset as the corresponding PFP A pre-calculated to generate a hologram (ISH), and then the reverse image position correction process is performed by multiplying three different phase shifting factors to restore the three channel main images to their original overlap positions, and 4-f
  • ISH hologram
  • the optical pinhole array filter on the Fourier side of the lens system easily blocks the image caused by color scattering and can be removed from the final primary color image because the spatial position of the frequency spectrum is shifted individually.
  • a full color holographic display method extracts an input 3D object image into one frame input image group consisting of R, G, and B images and a depth image.
  • the image shifted R, G, and B-holograms are computed by the NLUT method with three groups of modulated precomputed PFPs, during which only the image position changes with three groups of modulated PFPs, but the spatial position of each channel's frequency spectrum Does not change, and then the three image shifted holograms are multiplied by three different phase shifting factors to recover the position shifted image caused by the image shifting process to the original overlapping position, this process
  • the frequency spectrum of each channel hologram After the two types of image position correction process, the position of each channel main image is in the same original position and the frequency spectrum is well separated in the Fourier plane, encoded by three channel DS-holograms When the CMH is loaded into the SLM, the frequency spectrum
  • the present invention has a remarkable effect of directly controlling the frequency spectrum position of the RGB channel hologram at the same time as the simplified image shifting and phase shifting process.
  • Figure 2 is a video moving process of the DS method: (a) the original NLUT calculation process, (b) (a), (a ') NLUT calculation process using the position-shifted PFP, (b') image shifted hologram (a ' And (c) the plan view of the image affected by the spatial position and image shifting process on the Fourier plane
  • phase shifting process of the DS method (a) an image shifted hologram calculated by the NLUT method with image shift processing, and (c) a spatial position diagram on the Fourier plane and the image plane affected by the phase shift process.
  • ISH image-shift-holograms
  • the reverse image position correction process is performed by multiplying three different phase shifting factors to restore the three channel main images to their original overlap positions.
  • the optical pinhole array filter on the Fourier side of the 4-f lens system can easily block the image caused by color dispersion and remove it from the final primary color image because the spatial position of the frequency spectrum is shifted separately.
  • the method shifts to another position by the phase shift process.
  • the method proposed in the present invention can directly control the frequency spectral position of the RGB channel hologram at the same time as the simplified image shifting and phase shifting process than the direct frequency spectrum processing method.
  • the flowchart of Fig. 1 shows a flowchart of the proposed system, which consists of two main step processes: digital process and optical process.
  • the input 3D object image is extracted into one frame input image group consisting of R, G, and B images and a depth image.
  • Image-shifted R, G and B-holograms are calculated by the NLUT method into three groups of modulated pre-calculated PFP. In this process, only the image position changes to three groups of modulated PFP, but the spatial position of the frequency spectrum of each channel does not change.
  • the three image shifted holograms are multiplied by three different phase shifting factors to recover the position shifted image caused by the image shifting process to the original overlapping position.
  • the CGH of an object image can be calculated simply by moving and adding the cropped PFP. This is why the NLUT method is adopted instead of other CGH algorithms. Then, by moving the center of the concentric circle of each channel PFP group to the same distance, the reconstructed image of the calculated hologram pattern will also have the same distance shift without further processing. As shown in Fig. 2 (a), the hologram patterns for the three points A, B and C of the input image are cut out in areas different from the original PFP.
  • the points A, B, and C in the image are the hologram pattern of the center object point A of the crop region of the PFP because the positions of the distance movement with the center point O are (0, 0), (-xb, -yb) and (xc, yc), respectively.
  • B and C must move (0, 0), (xb, -yb) and (-xc, -yc) to the center position with a predetermined area.
  • the proposed image shifting method can provide the image in any shifting manner by shifting the center position of the precalculated PFP in the NLUT method. (One).
  • H, ap, and PFP represent the final hologram, the intensity value of the pth target point, and the precomputed fringe pattern of the zPth depth, respectively.
  • x, y, a and b are the coordinates and travel distance of the recorded image along the x and y axes, respectively.
  • xp and yp are the travel distances of the center of the predetermined cropping area for the pth point.
  • the precomputed fringe pattern can be precomputed by equation (5). (2)
  • k0 2p / ⁇ and ⁇ means the wave number and wavelength of the light source.
  • the resolution of the PFP should be set large enough for side shifting, addition and cutting operations in the hologram generation process.
  • the minimum resolution of the PFP can be expressed as follows. (3-4). Eqs. In (3-4), hx and hy represent the horizontal resolution and the vertical resolution of the hologram pattern, and Ox and Oy represent the sampling step and the horizontal and vertical image sizes, respectively.
  • fori (fx, fy) F ⁇ hori (x, y) ⁇
  • fshifted_c and fori mean the frequency spectrum of the image shifted hologram and the original hologram.
  • the parameters ac, bc, fa_c and fb_c represent the image shifted distance along the x and y axes and the phase coefficients of the frequency spectrum, respectively.
  • the subscript c means other colors such as R, G, B.
  • the frequency spectrum of the image shifted hologram is equal to the result of multiplying the phase factor which causes a change in propagation direction when the image position is shifted.
  • the image shifting process separates the R, G, and B channel images into different shifting distances, so the phase shift process recovers the R, G, and B channel images together so that the RGB channel main image and the final color image.
  • three different phase shifting factors are each multiplied by three image shifted holograms, which are represented by equation (6).
  • the propagation direction of the reconstructed image is changed by the phase shifting factor so that the R, G, B channel reconstructed image of the hologram shifted to the R, G, B image is moved to the original position through the propagation angle correction.
  • this method will cause a depth change due to the image point rotated around the center of the hologram when the reconstructed image position is changed using the propagation angle correction by the proposed phase shift method. Depth change can be calculated by equation (5).
  • ⁇ x, ⁇ y, ⁇ y, z are the total depth change, the depth change by the image rotating along the x-axis, the depth change by the image rotating along the y-axis, the image shifted distance the image rotating along the x-axis, rotating along the y-axis
  • the image is represented by the image shifted distance by the angle rotated along the x-axis, the angle rotated along the y-axis, and the reconstructed distance away from the hologram.
  • the depth change amount ⁇ D can be ignored. But if not, you need to take into account the change in depth. However, the present invention ignores this depth change due to the huge difference between the reconstructed distance z and the moved distance ⁇ x and ⁇ y.
  • Equation (8) the effect of the frequency spectrum by the phase shift method is expressed by Equation (8).
  • the frequency spectrum of the phase shifted hologram has the same result as shifted by a constant distance along the X and Y axes in the frequency spectrum, which can also cause a change when the phase shifting factor is multiplied during the inverse-modulation process, which
  • the proposed phase shift method can modulate the image position by changing the direction of propagation that occurs by multiplying the hologram with the phase factor. It adopts the proposed image shift method and phase shift method as the modulation and demodulation process for separating and reconstructing this three channel reconstruction image.
  • the difference with the image shift method is that the phase shift method modulates the spatial coordinates of the frequency spectrum on the Fourier plane, as well as the image position on the reconstructed image plane.
  • SLM-CD and CMH-CD are two types of color dispersion that are unavoidable in a CMH-based single SLM full color hologram display system.
  • unwanted color dispersion images caused by SLM-CD are removed by color filters or pinhole filters on the Fourier plane, other unwanted component images by CMH-CD are removed by separating these three channel spectra, Filter out unwanted spectrum. Therefore, in the present invention, by using a double shifting method combining image shift and phase shift, it is possible to separate the three-channel spectrum in the region other than the messed up image, and the unwanted image due to the SLM-CD and CMH-CD is a Fourier plane. Use a specially designed pinhole array filter.
  • the MD-CMH is loaded into an SLM located in the input plane of the 4-f lens system and illuminated by a parallel light source consisting of three R, G and B-lasers.
  • the DS-CMH is optically converted to the Fourier domain, where separate R, G and B channel spatial frequency spectra of the DS-CMH are obtained. That is, as shown in Figure 4, the frequency spectra Rr, Gr and Br, reconstructed from the R channel DS-hologram due to color dispersion, appear on the left side of the G and B channel spectra, which leads to an image shifting and phase shifting process. Illustrated. 2 and 3.
  • an optical pinhole array filter on the Fourier plane of a 4-f lens system can block all color scattered spectra, as shown in Figure 4 (b), and the original primary Rr, Gg And the Bb-frequency spectrum are transmitted as shown in FIG. Therefore, through the band pass filtering process using the optical pinhole filter, the proposed system can solve related images due to color dispersion.
  • frequency spectral aliasing occurs because of the low pass filtering process for each spectrum in the separate R, G, and B channel spectra.
  • most of the energy in each frequency spectrum is concentrated in the center of the high light spot, and a pinhole filter is used to filter the high frequency region of each spectrum. The aliased portion of the spectrum is then blocked by the pinhole filter in this method without using an extra low pass filtering process.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Holo Graphy (AREA)

Abstract

La présente invention concerne un procédé d'affichage holographique en couleurs dans une SLM unique basée sur un FDM à l'aide d'un procédé de décalage double, dans lequel trois groupes PFP ayant des décalages centraux différents sont précalculés de façon à produire trois hologrammes de décalage d'image de canal (ISH) avec les mêmes décalages que les PFP correspondants, ensuite un processus de correction de position d'image inverse est effectué en multipliant trois images principales de canal par trois facteurs de décalage de phase différents de façon à restaurer les trois images principales de canal vers des positions de chevauchement d'origine, et une position spatiale d'un spectre de fréquence individuellement mobile en tant qu'image résultant de la dispersion chromatique est facilement bloquée par un filtre à réseau sténopéique optique sur le côté de Fourier d'un système de lentille 4-f de sorte qu'il soit possible d'effectuer une élimination d'une image de couleur primaire finale. En conséquence, la présente invention a un effet significatif selon lequel il est possible de commander directement une position d'un spectre de fréquence d'un hologramme de canal RVB simultanément avec un mouvement d'image simplifié et un processus de décalage de phase.
PCT/KR2018/005857 2018-05-23 2018-05-23 Procédé d'affichage holographique en couleurs dans une slm unique basée sur un fdm à l'aide d'un procédé de décalage double WO2019225778A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/KR2018/005857 WO2019225778A1 (fr) 2018-05-23 2018-05-23 Procédé d'affichage holographique en couleurs dans une slm unique basée sur un fdm à l'aide d'un procédé de décalage double

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/KR2018/005857 WO2019225778A1 (fr) 2018-05-23 2018-05-23 Procédé d'affichage holographique en couleurs dans une slm unique basée sur un fdm à l'aide d'un procédé de décalage double

Publications (1)

Publication Number Publication Date
WO2019225778A1 true WO2019225778A1 (fr) 2019-11-28

Family

ID=68616771

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2018/005857 WO2019225778A1 (fr) 2018-05-23 2018-05-23 Procédé d'affichage holographique en couleurs dans une slm unique basée sur un fdm à l'aide d'un procédé de décalage double

Country Status (1)

Country Link
WO (1) WO2019225778A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130099650A (ko) * 2012-02-29 2013-09-06 엘지전자 주식회사 홀로그래픽 디스플레이 장치 및 3차원 동영상의 중복성을 이용한 홀로그램 생성 방법
KR20140062883A (ko) * 2012-11-15 2014-05-26 삼성전자주식회사 홀로그래픽 디스플레이
JP2014197002A (ja) * 2014-04-15 2014-10-16 セルオプティック、インコーポレイテッドＣｅｌｌｏｐｔｉｃ， Ｉｎｃ． 受信電磁放射線から物体の３次元情報を抽出するシステム、装置および方法
KR20170132452A (ko) * 2016-05-24 2017-12-04 연세대학교 산학협력단 다파장 디지털 홀로그래피 시스템

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130099650A (ko) * 2012-02-29 2013-09-06 엘지전자 주식회사 홀로그래픽 디스플레이 장치 및 3차원 동영상의 중복성을 이용한 홀로그램 생성 방법
KR20140062883A (ko) * 2012-11-15 2014-05-26 삼성전자주식회사 홀로그래픽 디스플레이
JP2014197002A (ja) * 2014-04-15 2014-10-16 セルオプティック、インコーポレイテッドＣｅｌｌｏｐｔｉｃ， Ｉｎｃ． 受信電磁放射線から物体の３次元情報を抽出するシステム、装置および方法
KR20170132452A (ko) * 2016-05-24 2017-12-04 연세대학교 산학협력단 다파장 디지털 홀로그래피 시스템

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SHU-FENG LIN: "Single SLM full-color holographic 3-D display based on sa mpling and selective frequency-filtering methods", OPTICS EXPRESS, 15 May 2017 (2017-05-15), pages 11389 - 11404, XP055658157 *

Similar Documents

Publication Publication Date Title
JP6349282B2 (ja) ホログラムを計算する方法
KR100923523B1 (ko) 컴퓨터 생성 비디오 홀로그램을 인코딩하고 재구성하는방법 및 장치
Lin et al. Full-color holographic 3D display system using off-axis color-multiplexed-hologram on single SLM
CN105954993B (zh) 一种基于空间划分的彩色全息三维显示方法及其系统
JP2010528324A5 (fr)
Kang et al. Color holographic wavefront printing technique for realistic representation
WO2015108272A1 (fr) Dispositif d'enregistrement de front d'onde holographique et procédé de reproduction d'images holographiques en couleur sans discontinuité
DK0921449T3 (da) Computerstyret holografisk metode og indretning
WO2019225778A1 (fr) Procédé d'affichage holographique en couleurs dans une slm unique basée sur un fdm à l'aide d'un procédé de décalage double
KR101423163B1 (ko) 홀로그래픽 프린지 패턴을 호겔 단위로 필터링하여 홀로그래픽 기록매질에 기록하는 홀로그래픽 프린터 및 그의 홀로그래픽 프린팅 방법
Yang et al. Large scale and high resolution computer generated synthetic color rainbow hologram
US20140009807A1 (en) Method and apparatus for space division multiplexed color holographic display
WO2019225776A1 (fr) Système d'affichage vidéo tridimensionnel basé sur un hologramme en ligne avec une structure simple ayant un angle de vision omnidirectionnel sur la base d'un procédé de filtrage de bande multifréquence à symétrie centrale
JP3886036B2 (ja) 立体表示装置
CN113406874B (zh) 单空间光调制器实现彩色立体点云裸眼显示系统和方法
GB2214651A (en) Colour Holograms
KR20200122917A (ko) 디지털 홀로그램 영상 화질 개선 장치 및 그 방법
CN110308610A (zh) 一种基于全息投影的多视图三维显示装置及控制方法
Yu et al. White light transmission color holography: a review
Kang et al. Color holographic wave-front printing technique
Li et al. Large-size holographic display method based on effective utilization of two spatial light modulators
CN111880390B (zh) 一种基于白光照明的彩色全息3d显示系统
Kang et al. Color holographic wave-front printing method based on partitioned elemental hologram
Nakamura et al. Approach to the multicolor imaging from computer-generated hologram
CN115657434A (zh) 一种基于频移和像移复用的全息图频谱操纵方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18919684

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18919684

Country of ref document: EP

Kind code of ref document: A1