• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1139-1142
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• 2007

In this paper, an image enhancement method by saturation and contrast improvement is proposed. Histogram equalization with color difference makes higher contrast. By generating saturation amplification ratio with color difference, the saturation improves effectively. The experimental results show that the proposed algorithm has higher contrast and more natural - look than the conventional methods.

• 전기학회논문지P
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• 제62권2호
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• pp.90-94
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• 2013

In this paper, we propose a new algorithm to improve the contrast ratio, to preserve information of bright regions and to maintain the color of backlight image that appears with a great relative contrast. Backlight images of the natural environment have characteristics for difference of local brightness; the overall image contrast improvement is not easy. To improve the contrast of the backlight images, MSR (Multi-Scale Retinex) algorithm using the existing multi-scale Gaussian filter is applied. However, existing multi-scale Gaussian filter involves color distortion and information loss of bright regions due to excessive contrast enhancement and noise because of the brightness improvement of dark regions. Moreover, it also increases computational complexity due to the use of multi-scale Gaussian filter. In order to solve these problems, a linear MSR is performed that reduces the amount of computation from the HSV color space preventing the color distortion and information loss due to excessive contrast enhancement. It can also remove the noise of the dark regions which is occurred due to the improved contrast through edge preserving filter. Through experimental evaluation of the average color difference comparison of CIELAB color space and the visual assessment, we have confirmed excellent performance of the proposed algorithm compared to conventional MSR algorithm.

• 대한방사선기술학회지:방사선기술과학
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• 제23권1호
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• pp.91-96
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• 2000

This work was on the reduction of exposure dose and contrast improvement by Use of Heavy Elements Filter From the result of experimental evaluation, it was found that the beam harding of X-ray was not showed in Ho and Gd, heavy elements filters, contrast to Cu and Al filters In which the harding showed. And the ratio of transit dose to surface dose and the load of X-ray tube increase in order of Al, Cu, Gd and Ho, respectively. The contrast of X-ray images using the intensifying screen and the input phosphor showed the higher value in order of Cu, Al, Gd and Ho. Therefore, in the case of using contrast media and phosphor in region of diagnostic radiology, X-ray image quality depends primarily on kVp and heavy elements filters.

• Journal of the Optical Society of Korea
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• 제19권1호
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• pp.22-28
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• 2015

We propose a new method for improving the phase contrast of a multiphase digital holographic microscope using a spatial light modulator (SLM). Using the SLM as the annulus, our method improves the light contrast of the object edge to achieve higher accuracy. We demonstrate a digital holographic microscopy technique that provides a 30% improvement in the phase contrast compared to conventional microscopy, which utilizes a mechanical annulus. The phase-contrast improvement allows the 3D reconstructed hologram to be determined more precisely.

• 한국멀티미디어학회논문지
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• 제5권6호
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• pp.609-615
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• 2002

본 논문은 LCD 모니터 상에서 영상 향상을 위한 콘트라스트 제어방식을 제안하였다. 제안한 방식은 입력되는 필드 혹은 프레임 중에서 화소의 최대 값과 최소 값을 판별하고 이를 이용하여 화면의 개선 정도를 결정한다. 필드 또는 프레임의 메모리가 필요하지 않고, 기존의 방식에 비해 하드웨어 구성이 간단하여 실시간 처리를 요하는 분야에 쉽게 적용 가능하다 또한 입력되는 콘트라스 영역의 가중치 값을 변화시킴으로써 콘트라스트 제어가 가능하다 제안한 방법은 콘트라스트 제어 알고리즘과 룩업 테이블을 이용한 영상의 모드에 따라선택적으로 가중치 기울기를 구간별로 달리하여 개선된 영상을 얻는다. 제안한 다계조 콘트라스트 제어 방식을 컴퓨터 시뮬레이션을 통하여 검증하였으며, 시뮬레이션을 통해 영상을 확인하였다.

• 한국식품영양과학회:학술대회논문집
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• 한국식품영양과학회 2001년도 International Symposium on Food,Nutrition and Health for 21st Century
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• pp.52-60
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• 2001

Purpose: We performed a randomized, double-blind, placebo-controlled trial in mild to moderate myopia patients to evaluate the benefit of taking a nutrient supplement containing anthocyanoside oligomers for improving nocturnal visiual function and/or clinical symptoms. Methods: The subjects included have refractive error between -lD(Diopters) $\~$-8D in both eyes, symptoms of decreased night vision and asthenopia based on the scoring result of a pre-structured questionnaire, and abnormal results of mesopic contrast sensitivity(MCS) screening test showing abnormal curve of contrast sensitivity in the middle and high frequency level, between 6.0 and 30.0 CPD(Cycles per degree) at mesopic condition(-2$\~$0 log cd/$m^2$). Total 60 people who qualified the criteria above were enrolled and the subjects were instructed to take the investigational product (anthocyanoside or placebo) twice daily for a 4 week period. The enrolled subjects were investigated for nocturnal vision performance by MCS and clinical symptoms at their first visit and re-evaluated at post-intervention (4 weeks later). MCS was measured and improvement of contrast threshold level according to each CPD was calculated by subtracting initial values from final values. Age, refractive error, and MCS were compared between the placebo and anthocyanoside. Results: After 4 weeks of drug administration 22 of the anthocyanoside group showed symptom improvement compared to 1 of the placebo group (p=0.000). Contrast sensitivity levels according to each CPD before and after drug treatment showed significant improvement in the anthocyanoside group but not in the placebo group. Mean MCS change of anthocyanoside group is 2.41$\pm$1.91 which showed significant improvement compared to -0.40$\pm$2.47 of the placebo group(p=0.000). MCS changes of anthocyanoside group showed significant improvement compared to placebo group in all levels of CPD(p<0.05). During our investigation none of the subjects complained of specific side effects related to anthocyanoside use. Conclusion: Our results show that under careful selection of people with significant symptoms and definite MCS abnormalities, anthocyanoside oligomers may improve the subjective symptoms and objective MCS results.

• 전자공학회논문지SC
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• 제45권1호
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• pp.15-24
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• 2008

본 논문은 영상의 블록기반 지역 명암대비 향상을 통한 전역 명암대비 향상 기법을 제안한다. 전역 명암대비 향상 기법은 영상의 특성을 고려하지 않고 히스토그램 평활화만을 통해 명암값의 재분배를 수행함으로써 과도한 밝기값의 화소들을 갖는 결과영상을 유발한다. 반면에 블록기반 지역 명암대비 향상 기법은 블록화 현상 및 이를 줄이는 과정에서 영상의 중요한 특징을 훼손하는 문제점을 갖고 있다. 이런 문제점들을 해결하기 위해 본 논문은 입력영상을 다양한 블록 크기로 분할한 임시영상들에 대해 블록기반 히스토그램 평활화를 수행한다. 그리고 지역 명암대비 향상을 통해 얻어진 전역 히스토그램 평활화 함수를 원 영상에 적용하는 전역 명암대비 향상 기법을 수행한다. 지역 명암대비가 향상된 임시 영상으로부터 전역 히스토그램 평활화 함수를 얻기 때문에 제안하는 방법은 지역 명암대비 향상 기법과 전역 명암대비 향상 기법의 장점들을 갖는다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.369-370
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• 2007

In this paper, an image enhancement method by saturation and contrast improvement is proposed. Histogram equalization with color difference makes higher contrast. By generating saturation amplification ratio with color difference, the saturation improves effectively. The experimental results show that the proposed algorithm has higher contrast and more natural - look than the conventional methods.

• Journal of Ginseng Research
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• 제45권6호
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• pp.676-682
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• 2021

Background: Red ginseng has been found to improve ocular perfusion and dry eye syndrome in glaucomatous eyes; however, its effects on visual function and vision-related quality of life have not been investigated. This study sought to evaluate the effects of red ginseng on visual function and vision-related quality of life in glaucoma patients using contrast sensitivity and a questionnaire. Methods: Participants were randomly assigned to two groups in this prospective, randomized, double-blind study: in one group, red ginseng was taken first, followed by a placebo, and in the other, placebo was taken first, followed by red ginseng. We measured and compared changes in contrast sensitivity and vision-related quality of life between the two groups. Contrast sensitivity was measured using OPTEC® 6500P, and vision-related quality of life was evaluated using the 25-item National Eye Institute Visual Function Questionnaire. One-way and two-way repeated measure analyses of variance were used for the comparison. Relationships between respective changes in dry eye syndrome and contrast sensitivity were also analyzed. Results: Daytime contrast sensitivity and ocular pain improved after the administration of red ginseng. Nighttime contrast sensitivity was improved in early or moderate glaucoma. Improved contrast sensitivity was not associated with improvement in dry eye syndrome. Conclusion: Red ginseng could improve contrast sensitivity and ocular pain in patients with glaucoma. The mechanism underlying improvement in contrast sensitivity appears to be associated with enhanced retinal perfusion or retinal ganglion cell function, but not dry eye syndrome.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.740-743
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• 2005

The discussion of this study is that we proposed a new construction to improve the potency of LCOS projection monitor. We suggest a new construction that uses special optics coating to reduce the green channel and obtains a purer white field. Compared with the voltage method to adjust on the monitor, we can get higher contrast gradient.