• Journal of the Korean Physical Society
• /
• 제73권12호
• /
• pp.1845-1848
• /
• 2018

We introduce a process for optically reconstructing full-color holographic images recorded by optical scanning holography. A complex RGB-color hologram was recorded and converted into a binary hologram using a direct binary search (DBS) algorithm. The generated binary hologram was then optically reconstructed using a spatial light modulator. The discrepancies between the reconstructed object sizes and colors due to chromatic aberration were corrected by adjusting the reconstruction parameters in the DBS algorithm. To the best of our knowledge, this represents the first optical reconstruction of a full-color hologram recorded by optical scanning holography.

• Journal of the Optical Society of Korea
• /
• 제13권4호
• /
• pp.406-415
• /
• 2009

Optical scanning holography (OSH) is a distinct digital holographic technique in that real-time holographic recording a three-dimensional (3-D) object can be acquired by using two-dimensional active optical heterodyne scanning. Applications of the technique so far have included optical scanning cryptography, optical scanning microscopy, 3-D pattern recognition, 3-D holographic TV, and 3-D optical remote sensing. This paper reviews some of the recent progress in OSH. Some possible further works are also discussed.

• ETRI Journal
• /
• 제38권4호
• /
• pp.599-605
• /
• 2016

For the implementation of a real-time holographic camera, fast and automatic holographic image reconstruction is an essential technology. In this paper, we propose a new automatic depth-detection algorithm for fast holography reconstruction, which is particularly useful for optical scanning holography. The proposed algorithm is based on the inherent phase difference information in the heterodyne signals, and operates without any additional optical or electrical components. An optical scanning holography setup was created using a heterodyne frequency of 4 MHz with a 500-mm distance and 5-mm depth resolution. The reconstruction processing time was measured to be 0.76 s, showing a 62% time reduction compared to a recent study.

• Journal of the Optical Society of Korea
• /
• 제16권2호
• /
• pp.121-126
• /
• 2012

We propose a novel technique that records the horizontal-parallax-only (HPO) hologram of a real object using optical scanning holography (OSH). The proposing HPO-OSH is composed of a conventional OSH and an electronics low pass filter. When we scan an object along vertical direction before horizontal direction, the electronic low pass filter filters the vertical fringes with preserving horizontal fringes and gives an HPO hologram. To the best of our knowledge, this is the first time to record the HPO hologram using OSH without either truncation of the scanning beam or digital post processing.

• Journal of Information Display
• /
• 제3권3호
• /
• pp.12-16
• /
• 2002

We first review a real-time three-dimensional (3-D) holographic recording technique called optical scanning holography (OSH) and discuss holographic reconstruction using spatial light modulators (SLMs). We then present how the overall system can be used for 3-D holographic television (TV) display with a wide-angle view of a 3-D image, and address some of the issues encountered. Finally, we suggest some techniques to alleviate the issues encountered in such a 3-D holographic TV system.

• Current Optics and Photonics
• /
• 제5권6호
• /
• pp.680-685
• /
• 2021

We propose a technique that reconstructs a hologram whose pixel number is greater than the pixel numbers of a conventional image sensor. The pixel numbers of the hologram recorded by optical scanning holography (OSH) increases as the scan area becomes larger. The reconstruction time also increases drastically as the size of the hologram increases. The holographic information of a three-dimensional (3D) scene is distributed throughout the recorded hologram; this makes the simple divide-and-stitch approach fail. We propose a technique that reconstructs the hologram without loss of holographic information. First, we record the hologram of a 3D scene using OSH. Second, we segment the hologram into sub-holograms that contain complete holographic information. Third, we reconstruct the sub-holograms simultaneously. Finally, we rearrange the reconstructions of the sub-holograms.

• 한국광학회지
• /
• 제26권5호
• /
• pp.249-254
• /
• 2015

본 논문에서는 광 스캐닝 홀로그래피를 이용한 양안식 3차원 홀로그래픽 영상 시스템을 제안하였다. 양안식 3차원 홀로그래픽 영상 시스템을 구현하기 위하여 사람의 두 눈 사이의 거리와 동공의 크기를 고려하여 양안식 3차원 홀로그래픽 디스플레이 시스템을 설계한 뒤 실제 물체의 홀로그램 정보를 획득하였고 수치적인 신호 처리 후 세기 형태의 공간 광 변조기를 이용하여 광학적인 방법으로 복원하였다. 이를 통하여 광 스캐닝 홀로그래피를 이용한 양안식 3차원 홀로그래픽 영상 시스템의 구현 가능성을 실험적으로 확인하였다.

• Journal of the Optical Society of Korea
• /
• 제4권1호
• /
• pp.48-53
• /
• 2000

In Optical Scanning Holography(OSH), 3-D holographic information of an object is generated by 2-D active optical scanning. The optical scanning beam can be a time-dependent Gaussian apodized Fresnel zone plate. In this technique, the holographic information manifests itself as an electric signal which can be sent to an electron-beam-addressed spatial light modulator for coherent image reconstruction. In this paper, we briefly review optical scanning holography and analyze the resolution achievable with the system. We also present mathmatical expressions of real and virtual images which are responsible for holographic image reconstruction. We then show the twin-image noise effect on the reconstruction in conjunction with the size of the Fresnel zone pattern through computer simulation.

• 한국광학회지
• /
• 제25권3호
• /
• pp.142-145
• /
• 2014

본 논문에서는 광 스캐닝 홀로그래피 기술을 이용하여 실제 물체의 복소 홀로그램 정보를 스펙클 잡음 없이 촬영하였다. 촬영된 복소 홀로그램 정보를 수치적인 방법으로 복원한 뒤 결맞음 광원과 CCD 카메라를 이용하여 촬영한 실제 물체의 영상과 비교하여 스펙클 잡음에 의한 오염도를 평가하였다. 스펙클 잡음에 의한 오염도를 정량적으로 평가하기 위하여 두 영상의 스펙클 패턴의 대비 수치를 이용하였다.

• 한국광학회지
• /
• 제22권1호
• /
• pp.10-15
• /
• 2011

본 논문에서 홀로그램의 일부 영역만을 선택하여 자동 초점 맺는 방법을 제안하고 이를 실험적으로 보였다. 먼저 광 스캐닝 홀로그래피를 이용하여 복소 홀로그램을 추출한다. 그 다음 홀로그램의 일부 영역만을 선택하고 가우시안 저대역 필터링, Real-only 홀로그램 합성, Power fringe-adjusted 필터링, 주파수축 변환 등의 과정을 통해 깊이 정보를 추출한다. 이렇게 추출된 깊이 위치를 이용하여 홀로그램을 자동적으로 복원하게 된다.