• 한국방사선학회논문지
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• 제13권4호
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• pp.623-628
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• 2019

본 연구의 목적은 시간 분해능이 향상된 비지역적 평균 (fast non local means, FNLM) 노이즈 제거 알고리즘을 모델링하여 광학 현미경 영상에서의 적용 가능성을 확인하는 것이다. 이를 위해 실제 흰쥐 (mouse)의 첫째어금니 치아를 사용하여 영상을 획득한 후 기존에 널리 사용되고 있는 노이즈 제거 알고리즘과 제안하는 FNLM 알고리즘을 각각 적용하여 비교하였다. 정량적 평가는 대조도 대 잡음비 (contrast to noise ratio, CNR), 변동계수 (coefficient of variation, COV), 그리고 최근에 개발된 no reference 기반의 방법인 natural image quality evaluator (NIQE)와 Blind/referenceless image spatial quality evaluator (BRISQUE)를 사용하였다. 결과적으로 모든 정량적 평가 인자에서 제안하는 FNLM 노이즈 제거 알고리즘이 가장 우수한 값을 나타내었다. 특히나 치아의 전체적인 형태학적 영상을 분석할 수 있는 NIQE와 BRISQUE 인자는 원본영상에 비하여 각각 1.14와 1.12배 향상됨을 확인할 수 있었다. 결론적으로 소동물 치아 광학 현미경 영상에서의 FNLM 노이즈 제거 알고리즘의 유용성 및 가능성을 증명하였다.

• Corrosion Science and Technology
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• 제15권6호
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• pp.265-270
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• 2016

The ellipso-microscopic observation of a titanium surface undergoing anodization in $0.05mol\;dm^{-3}$ of $H_2SO_4$ was conducted. During irradiation by ultra-violet (UV) light with a wavelength of 325 nm, the titanium surface allowed for the flow of a photo-induced current and showed up as a bright, patch-like image on an ellipso-microscopic view. The brightness and patch-pattern in the image changed with flowing photo-induced current. The changes in the brightness and the image corresponded to the formation and/or degradation of titanium oxide due to the photo-electrochemical reaction of the oxide. An in situ monitoring using the ellipso-microscope revealed that the film change was dependent on the irradiation light power, by UV-light increases the anodic current and results in the initiation of pitting at lower potentials as compared with the non-irradiated condition.

• 한국안광학회지
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• 제10권1호
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• pp.9-15
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• 2005

CR 렌즈에 가한 미세응력 크기의 시각화를 위한 편광기는 광원-편광판-시료-편광판-CCD-컴퓨터-chrome 변환 로 구성하였고, 각 편광판의 단계별 광 파의 $E_1$, $E_2$의 성분을 분석하여, 주 응력차 ${\sigma}_1-{\sigma}_2$와 무늬 차수(n)를 유도하였다. 시료의 광 축이 주 응력 방향과 일치하는 것으로부터 2 차원 모델을 결정할 수 있다. 광파에 작용하는 이중 굴절성과 위상 지연은 주 응력차(${\sigma}_1-{\sigma}_2$)에 비례하며, 최종 광 파의 세기는 $sin^2({\Delta}/2)$에 비례하고, ${\Delta}/2=n{\pi}$ (n=0, 1, 2, ${\ldots}$)일 때 흡광이 일어난다. 미세 응력에 의한 광탄성은 chrome 변환을 이용하여 분석 가능하였으며, 이미지는 뚜렷하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제46권3호
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• pp.207-217
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• 2023

Image noise reduction algorithm performs important functions in light microscopy. This study aims to systematically review the research trend of types and performance evaluation methods of noise reduction algorithm in light microscopic images. A systematic literature search of three databases of publications from January 1985 to May 2020 was conducted; of the 139 publications reviewed, 16 were included in this study. For each research result, the subjects were categorized into four major frameworks-1. noise reduction method, 2. imaging technique, 3. imaging type, and 4. evaluation method-and analyzed. Since 2003, related studies have been conducted and published, and the number of papers has increased over the years and begun to decrease since 2016. The most commonly used method of noise reduction algorithm for light microscopy images was wavelet-transform-based technology, which was mostly applied in basic systems. In addition, research on the real experimental image was performed more actively than on the simulation condition, with the main case being to use the comparison parameter as an evaluation method. This systematic review is expected to be extremely useful in the future method of numerically analyzing the noise reduction efficiency of light microscopy images.

• 한국정밀공학회지
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• 제22권11호
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• pp.64-71
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• 2005

In order to measure surface roughness profile, stylus type equipments are commonly used, but the stylus keeps contact with surface and damages specimens by its tip pressure. Therefore, optics based measurement systems are developed, and light phase interferometer, which is based on light interference phenomenon, is the most noticeable research. However, light interference based measurements require translation mechanisms of nano-meter order in order to generate phase differences or multiple focusing, thus the systems cannot satisfy the industrial need of on-the-machine and in-process measurement to achieve factory automation and productive enhancement. In this research, we focused light reflectance phenomenon rather than the light interference, because reflectance based method do not need translation mechanisms. However, the method cannot direct]y measure surface roughness profile, because reflected light consists of several components and thus it cannot supply surface height information with its original form. In order to overcome the demerit, we newly proposed an image processing based algorithm, which can separate reflected light components and conduct parameterization and reconstruction process with respect to surface height information, and then confirmed the reliability of proposed algorithm by experiment.

• Journal of Digestive Cancer Reports
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• 제7권2호
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• pp.31-39
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• 2019

The early detection of early gastric cancer (EGC) is important. However, the sensitivity of conventional white light imaging (WLI) in detecting EGC had been reported to range only from 77% to 84%. Although the resolution of endoscopes has been remarkably developed, precancerous lesions such as adenomas and microscopic early cancers are difficult to diagnose with general endoscopy. Linked Color Imaging (LCI) magnifies the differences in color for easy detection. Therefore, it produces a bright image from a distance and is performed for screening endoscopy. The 410 nm wavelength of BLI (Blue Light Imaging) helps to detect cancer by showing microstructure and microvessels in the mucosal superficial layer. This review will focus on the utility of Image enhanced endoscopy (IEE) techniques in diagnosis of gastrointestinal cancer.

• 제어로봇시스템학회논문지
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• 제10권3호
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• pp.239-248
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• 2004

Optical coherence tomography(OCT) is high resolution imaging system which can see the cross section of microscopic organs in the living tissue. In this paper, we analyze the relation between the light source and the resolution of modulated signal in Michelson interferometer. We construct 1-D OCT signal processing hardware such as amplifiers, filters, and demodulate electronic signals from the photo detector. In order to get 2-D OCT image, the synchronization among optical delay line, sample stage and A/D converter is dealt with. In experiments, we verify analog and digital signal processing blocks which apply to the stacks of glasses. Finally we aquire high resolution 2-D OCT image with respect to the onion tissue. We expect that this result can be applied to the medical instrument through performance improvement.

• Journal of Biosystems Engineering
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• 제38권1호
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• pp.55-63
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• 2013

Purpose: The present study aimed at image processing methods for automatic cell pattern recognition and morphological analysis for tissue engineering applications. The primary aim was to ascertain the novel algorithm of adaptive brightness correction from microscopic images for use as a potential image analysis. Methods: General microscopic image of cells has a minor problem which the central area is brighter than edge-area because of the light source. This may affect serious problems to threshold process for cell-number counting or cell pattern recognition. In order to compensate the problem, we processed to find the central point of brightness and give less weight-value as the distance to centroid. Results: The results presented that microscopic images through the brightness correction were performed clearer than those without brightness compensation. And the classification of mixed cells was performed as well, which is expected to be completed with pattern recognition later. Beside each detection ratio of hBMSCs and HeLa cells was 95% and 92%, respectively. Conclusions: Using this novel algorithm of adaptive brightness correction could control the easier approach to cell pattern recognition and counting cell numbers.

• Restorative Dentistry and Endodontics
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• 제20권1호
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• pp.173-182
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• 1995

The purpose of this study was to evaluate the adaptability of light-cured glass ionomer cement to cavity walls. Class V cavities were prepared on the labial surfaces of extracted bovine incisor teeth. The cavities were restored with Fuji II as self-cured glass ionomer cement and Fuji II LC, Vitremer as light-cured glass ionomer cement. Fluorescent markers (fluoreceine and rhodamin B) were incorperated into liquid and primer for a better image of microscopic observation. Restored teeth were sectioned by longitudinal and labiolingual direction. The adaptability at the tooth-restoration interface was assessed incisally, axially and cervically by confocal scanning laser microscope. Following results were obtained : 1. Chemical-cured glass iomomer cement restoration showed close adaptation on the all of the cavity walls, but, cracks formed within the cement. 2. Light-cured glass ionomer cement restoration was well adapted to the cavity walls, but showed crack in the cement adjacent to axial dentinal wall. 3. There' was no significant difference in adaptability between two light-cured glass ionomer cement restorations.

• Fisheries and Aquatic Sciences
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• 제4권1호
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• pp.10-17
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• 2001

One serious problem among the troubles to identify objects in an optical microscopic image is contour background due to non-uniform light source and various transparency of samples. To solve this problem, this paper proposed an elimination method of the contour background and compensation technique as follows. First, Otsu's optimal thresholding method extracts pixels representing background. Second, bilinear interpolation finds non-deterministic background pixels among the sampled pixels. Third, the 2D cubic fitting method composes surface function from pivoted background pixels. Fourth, reconstruction procedure makes a contour image from the surface function. Finally, elimination procedure subtracts the approximated background from the original image. To prove the effectiveness of the proposed algorithm, this algorithm is applied to the yeast Zygosaccharomyces rouxii and ammonia-oxidizing bacteria Acinetobacter sp. Labeling by this proposed method can remove some noise and is more exact than labeling by only Otsu's method. Futhermore, we show that it is more effective for the reduction of noise.