Hee-Jin Choi

Prof. Hee-Jin Choi


Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 July 2014 in Optics Express
Verified
Journal Article
Open access
PDF file
YOYongseok Oh
Yongseok Oh
DSDonghak Shin
Donghak Shin
BLByung-Gook Lee
Byung-Gook Lee
SJShin-Il Jeong
Shin-Il Jeong
HCHee-Jin Choi
Hee-Jin Choi
Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.

1 January 2005 in Optics Express
Verified
Journal Article
Open access
PDF file
HCHee-Jin Choi
Hee-Jin Choi
YKYunhee Kim
Yunhee Kim
JPJae-Hyeung Park
Jae-Hyeung Park
JKJoohwan Kim
Joohwan Kim
SCSeongwoo Cho
Seongwoo Cho
Byoungho LeeByoungho Lee
Byoungho Lee
An improved integral imaging process is proposed that can display a depth-enhanced three-dimensional (3D) image by using two parallel-layered display devices. With the use of layered display devices, it is possible to construct 3D images on several depth planes and increase the depth remarkably. In addition, the translucent problem between 3D images was resolved for the first time to the author’s knowledge by a time-multiplexing method. The proposed method was proven and compared with the conventional one by preliminary experiments.

24 June 2019 in IEEE Photonics Journal
Verified
Journal Article
Open access
MPMinyoung Park
Minyoung Park
KJKyung-Il Joo
Kyung-Il Joo
HKHak-Rin Kim
Hak-Rin Kim
HCHee-Jin Choi
Hee-Jin Choi
An augmented-reality (AR) device which presents virtual volumetric images to switchable integrated spaces is proposed and demonstrated. A bi-focal geometric phase (GP) lens can project the integrated volumetric images to switchable integrated spaces by switching the polarization of them. For that purpose, a combination of GP lens and an active polarization switching device (APSD) has been adopted. A demonstration of an AR display with switchable integrations is also provided to verify the proposed concept.

20 January 2014 in Applied Optics
Verified
Journal Article
Closed access
PDF file
MPMinyoung Park
Minyoung Park
JKJoohwan Kim
Joohwan Kim
HCHee-Jin Choi
Hee-Jin Choi
To provide two-eyed views with one device, stereoscopic 3D (S3D) displays interlace the two views either temporally or spatially: temporal interlacing (TI) alternates the two views in time with full resolution, while spatial interlacing (SI) presents the two views simultaneously but with half resolution for each eye. We investigate the effect of interlacing methods on image quality through a psychophysical experiment. We compared four experimental conditions: three S3D interlacing methods (TI, SI with raw sampling, and SI with vertical interpolation), and one nonconventional interlacing method (vertical interpolation). The stimuli were 10 natural stereo images presented at nine levels of pixel sizes (0.64, 0.78, 0.89, 1.00, 1.28, 1.55, 1.78, 2.00, and 2.56 arcmin). To test the effect of interlacing methods per se, we provided all the experimental conditions to the subjects using a single experimental setup: a mirror stereoscope. The results show that TI does not degrade the image quality for any pixel size. SI degrades the image quality when the pixel size is relatively large, but the effect of the two SI methods does not differ significantly. Comparison of SI methods against the vertical interpolation method implies that the primary cause of the degradation in image quality for SI methods is the visibility of the interlacing pattern rather than the loss of high-frequency information.

27 March 2015 in Applied Optics
Verified
Journal Article
Closed access
PDF file
MPMinyoung Park
Minyoung Park
SLSeihyoung Lee
Seihyoung Lee
BLByung-Tak Lee
Byung-Tak Lee
HCHee-Jin Choi
Hee-Jin Choi
In this paper, a method to construct a directional-backlight unit system to separate the left-eye image and the right-eye image by adopting a double-slit barrier array is proposed to enhance the perceived quality of the realized 3D image. Additionally, the two-dimensional/three-dimensional convertible function is also realized by adopting an active diffuser to the spatial interlacing directional-backlight system.

2 November 2022 in Optics Express
Verified
Journal Article
Closed access
HLHyeontaek Lee
Hyeontaek Lee
JLJae-Won Lee
Jae-Won Lee
JSJungYeop Shin
JungYeop Shin
SHSunghee Hong
Sunghee Hong
HKHak-Rin Kim
Hak-Rin Kim
HCHee-Jin Choi
Hee-Jin Choi
A geometric phase (GP) integral floating display can provide multifocal three-dimensional (3D) augmented reality (AR) images with enhanced depth expression by switching the focal modes of the GP lens via polarization control. However, using temporal multiplexing to switch between the focal modes of GP optics causes flickering as each 3D AR image is fully presented in different frames and their temporal luminance profile becomes easily recognizable, particularly as the number of available focal modes increases. Here, we propose a novel integral floating technique to generate pixelated interwoven 3D AR images; a half of each image is spatially mixed with another and presented in both focal modes simultaneously to resolve the flickering issue. The principle was verified via experimental demonstration and optically measured data.