• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.79-87
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• 2008

Purpose: This study measured Y-intercept that means a fixation disparity, X-intercept that means a associated phoria and slope of a fixation disparity curve (FDC), which are variables of dissociated phoria and the FDC. We searched for the result value and examined the direction, distribution pattern and a variable that give an most affect on dissociated phoria and the FDC at distance and near. Also this study examined that there were statistically significant differences between distance and near, comparing the result value. Methods: We measured the dissociated phoria and the fixation disparity for 51 subjects at distance and near in June, 2007. All subjects ranged from 20 to 25 years of age (average 21.72${\pm}$1.88 years old) and had no eye disease. At distance the dissociated phoria measured with the distance MIM card (muscle imbalance measure card, Bernell co., USA), and the fixation disparity measured with the modified Mallett Far Unit (Bernell co., USA). At near the dissociated phoria measured with the near MIM card (muscle imbalance measure card, Bernell co., USA), and the fixation disparity measured with the Wesson fixation disparity card (American Optical co., USA). Results: The percentage distribution of types of fixation disparity curves was that at distance prevalence of Type I (74.6%) was the highest, followed by Type IV (17.6%) and Type II (3.9%), Type III (3.9%) and that at near prevalence of Type I (53.0%) was the highest, followed by Type III (29.4%), Type IV (13.7%) and Type II (3.9%). 2. There were significantly correlation in dissociated phoria, fixation disparity (Y-intercept) and associated phoria (X-intercept). 3. The fixation disparity at distance was most affected by associated phoria (X-intercept) (p=0.000). The distance dissociated phoria was most affected by fixation disparity (Y-intercept) (p=0.342), but the influence was weak. 4. The fixation disparity at near was most affected by associated phoria (X-intercept) (p=0.000). The near also dissociated phoria was most affected by associated phoria (X-intercept) (p=0.009). The result that compared the each variables with the same variables at distance and near had statistically significant on paired t-test for among dissociated phoria (t=7.529, p=0.000), X-intercept (t=5.860, p=0.000), the Y-intercept (t=4.640, p=0.000) but slope of the FDC did not differ significant (t=1.336 p=0.188). Conclusions: Relationship of fixation disparity and Heterophoria had close correlation at distance and near.

• Korean Journal of Optics and Photonics
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• v.25 no.1
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• pp.21-28
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• 2014

In this paper a Super Multi-view display method using a pinhole array with full parallax was proposed. The proposed method was simulated and its parameters analyzed. Also, the distribution and irradiance of light through each pinhole on the retina receiver, according to the change of crystalline lens focal length, were found by simulation. As a result, an image free of blurring was obtained while the crystalline lens focused on the depth plane of the three-dimensional image created by the imaging lens.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.369-375
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• 2009

In this paper, we propose a 2D-3D convertible display system having a background of full-parallax integral images. The proposed system is composed of integral imaging system and conventional 2D flat display and is able to operate either 3D mode or 2D mode. In 3D mode, the 3D image is generated by combining the 2D main image with the background image based on integral imaging. In 2D mode, the integral imaging system plays a role as the back-light of 2D flat display and then 2D image is observed through 2D flat display. To show the usefulness of the proposed system, we carry out the preliminary experiments and present the successful experimental results.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.93-104
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• 2004

In order to have a comfortable vision without any asthenopia in work place, it is very necessary to make a complete binocular correction in addition to the perfect correction of refractive deficits. For this, At first, the exact understanding of the required corrective value of the existing angular ametropia(associated phoria) is needed. The fact likely seems fact that a correction of refractive deficits could not to be reached with single optotype, the corrections of angular ametropia(associated phoria) with single optotype is impossible. The reason is that a most ametropia(associated phoria) is accompanied with the fixation disparity. To make a perfect measurement of ametropia(associated phoria), at least, 3 kinds of optotype is essential. This fact could be explained by stating the fusional stimulus in the binocular refraction tests on each eye. If these types of three tests have not practical practice. The most of many cases may result in undercorrection.

• Information and Communications Magazine
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• v.32 no.3
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• pp.52-59
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• 2015

렌즈어레이 기반의 3D 집적 영상 디스플레이 기술은 비교적 간단한 시스템 구조에서 무안경 방식의 완전시차(full parallax)를 가지는 3D 영상 표시가 가능하기 때문에 차세대 디스플레이 기술 중에 하나로 여겨지고 있다. 본 고에서는 이러한 렌즈어레이 기반의 3D 집적 영상 디스플레이에 대해서 소개하고, 최근에 성능 향상을 위하여 개발이 진행 중인 시간다중화 3D 집적 영상 디스플레이 기술과 콘텐츠 생성 기술에 대해서 설명한다.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.521-524
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• 2010

영상을 입체적으로 보는 방법에는 안경을 이용한 편광 방식과 시분할 방식, 안경이 필요 없는 패럴랙스 베리어, 렌티큘러, 다시점 방식 그리고 완전 3차원 방법들이 있다. 그 중에서도 안경을 이용하여 가장 쉽게 제작이 가능하고, 비용이 저렴한 애너그리프(Anaglyph) 방법이 흔히 사용된다. 애너그리프 영상을 생성하는 방법에도 여러 가지가 존재하고 최근까지 눈에 피로를 적게 하면서 입체감을 최대한 표현할 수 있는 영상을 생성하기 위한 연구가 진행되고 있다. 본 논문에서는 이러한 조건을 만족시키기 위하여 새로운 애너그리프 영상 생성 방법을 제안한다. 본 논문에서 제안하는 방법은 깊이 맵과 양안시차를 계산하여 가장 입체감 있는 애너그리프 영상을 생성 하는 방법이다. 깊이 맵의 계산을 통해 얻은 변이 정보와 실험적으로 계산한 사람 눈의 양안시차를 좌측 영상에 적용한다. 좌측 영상과 우측 영상을 최적화된 색상혼합방법을 사용하여 합성하면 제안한 방식의 애너그리프 영상이 생성된다. 본 논문에서 제안하는 방법은 기존의 초점을 고려하지 않는 애너그리프 방식의 문제점을 깊이 맵을 이용하여 해결할 수 있고 또한 양안시차를 고려하고 최적화된 색상혼합을 사용하기 때문에 눈에 피로가 적어진다.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.3
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• pp.321-327
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• 2013

Purpose: To investigate a correlation between vertical fixation disparity and stereopsis by analyzing distribution of types of vertical fixation disparity. Methods: In this study, RANDOT(R) stereotest partly using random dot was used in stereopsis tests. The vertical fixation disparity in close proximity categorized fixation disparity slope into six types on the basis of the result of measurement in when two thin lines, one for one eye looks, become overlapped as a line by adding into prism with Wesson fixation disparity card while maintaining a distance of 25 cm from patients. Results: In the types of near vertical fixation disparity curve, targeting 43 people, the first type 55.82% was the most distributed, the second type is the least 23.25%, the third type of 4.65%, the fourth type of 4.65%, the fifth type of 6.98%, the sixths types of 4.65% were distributed. The result of a correlation analysis, which shows the degree of linear correlation between two variables, represented that stereopsis is not correlated with Y-intercept (r = -0.07) which show vertical fixation disparity, associated phoria (r = -0.03) and dissociated phoria (r = -0.00), but it was not statistically significant (p>0.05). Fixation disparity slope of vertical fixation disparity (r = 0.36) was shown to have a positive correlation with stereopsis. It has a low positive correlation and a meaningful statistics (p<0.05). The Y-intercept which indicates vertical fixation disparity was also not associated with stereopsis (r = -0.07) and dissociated phoria (r = -0.03), and this was not statistically significant (p>0.05), while it had a high correlation as well as a statistically significant with associated phoria (r = 0.89). There was a negative correlation between Y-intercept and fixation disparity slope of vertical fixation disparity (r = -0.33). It showed a low relationship but statistically valuable (p>0.05). As a result of regression analysis, the stereopsis was changed as 7.631" if vertical fixation disparity changes 1' and the vertical fixation disparity changed as 0.017' if stereopsis changes 1', and the change was statistically significant (p<0.05). Conclusions: The study shows that there is a low correlation between stereopsis and vertical fixation disparity, and it is difficult to determine stereopsis only using vertical fixation disparity. Therefore, it suggests other factors above vertical fixation disparity have greater influence on stereopsis.

• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.79-89
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• 2023

A multi-view display is regarded as the most practical technology to provide a three-dimensional effect to a viewer because it can provide an appropriate viewpoint according to the observer's position. But, most multi-view displays with flat shapes have a disadvantage in that a viewer watches 3D images only within a limited front viewing angle. In this paper, we proposed a spherical display using a ball lens with spherical symmetry that provides perfect parallax by extending the viewing zone to 360 degrees. In the proposed system, each projection lens is designed to be packaged into a small modular array, and the module array is arranged in a spherical shape around a ball lens to provide vertical and horizontal parallax. Through the applied optical module, the image is formed in the center of the ball lens, and 3D contents are clearly imaged with the size of about 0.65 times the diameter of the ball lens when the viewer watches them within the viewing window. Therefore, the feasibility of a 360-degree full parallax display that overcomes the spherical aberration of a ball lens and provides a wide field of view is confirmed experimentally.

• Journal of Korea Multimedia Society
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• v.20 no.12
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• pp.2009-2015
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• 2017

A two-dimensional lens is required to reproduce both the horizontal and vertical parallax through an autostereoscopic 3D display. Among the two-dimensional lenses, a hexagonal micro lens array (MLA) having good optical efficiency is mainly used. However, the hexagonal MLA has complex geometric features. The first feature is that the lens cells are zigzagged in the vertical direction, which should be reflected in the view number calculation for each sub-pixel. The second feature is that the four sides of a hexagonal lens cell are tilted, requiring a more careful view index assignment to the lens cell. In this paper, we propose a sub-pixel multiplexing scheme suitable for the features of the hexagonal MLA. We also propose a view-overlay algorithm based on a two-dimensional lens and compare subjective image quality with existing view-selection through autostereoscopic 3D display implementation.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.301-302
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• 2013

본 논문에서는 집적 영상(Integral imaging)에서 3차원 영상을 자유시점에서 재생하는 방법에 대해 설명한다. 집적 영상은 완전시차와 연속적인 시점을 제공하기 때문에 자유시점 재생을 사용하여 3차원 물체의 측면을 재생할 수 있다. 따라서, 이러한 3차원 데이터를 사용하여 보다 향상된 3차원 영상의 시각화 및 패턴 인식이 가능할 수 있다. 이를 증명하기 위해 컴퓨터 시뮬레이션을 수행하였다.