• Electronics and Telecommunications Trends
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• v.32 no.5
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• pp.65-73
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• 2017

A holography technique optically reconstructs a three-dimensional object in space to provide a natural sense of depth and volume to the observer, thereby providing an ultimate 3D image capable of solving the problem of "vergence-accommodation conflict" occurring in a conventional stereoscopic imaging system. In this paper, we present a technical framework for measuring the performance and evaluating the quality of a holographic display, which enables a quantitative measurement of the optical and physical properties that affect the performance and quality of a holographic display. In addition, we provide the trend regarding standardization related to holographic display measurements. Although this trend has barely started, research activities related to holographic display measurements and quality evaluations are expected to grow in the near future.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.839-841
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• 1999

This paper presents the method of 3D reconstruction of the depth information from the endoscopic stereo scopic images. After camera modeling to find camera parameters, we performed feature-point based stereo matching to find depth information. Acquired some depth information is finally 3D reconstructed using the NURBS(Non Uniform Rational B-Spline) algorithm. The final result image is helpful for the understanding of depth information visually.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.186-188
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• 2001

In this study, the correlation between leakage currents and temperature rise was investigated for the more accurate diagnosis of bad insulator by use of the infrared camera. For the purpose, leakage currents and thermal images were measured for the artificially aged insulators using salt fog. From the results, it is concluded as follows ; in case of artificially aged insulators, the leakage. current was decreased with the duration of voltage application and was largely affected by humidity, which seems due to ionic conduction. Also, the correlation between temperature rise and leakage current was appeared to be quite linear, although it showed below linearity at large leakage current.

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.110-110
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• 2004

• Electronics and Telecommunications Trends
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• v.17 no.4 s.76
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• pp.65-74
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• 2002

멀티미디어 기술의 이용 증가와 더불어, 영상 압축은 새로운 기능과 보다 나은 성능을 필요로 한다. 정지영상 인코딩 분야에서 이 기술을 언급하기 위하여 JPEG2000이라 하는 새로운 표준이 최근 개발되고 있다. JPEG2000 기술은 기존의 표준기술보다 율왜곡, 영상성능 면에서 우수성을 제공할 뿐 아니라 또한 현재의 표준들이 언급할 수 없는 특징이나 기능들을 제공해준다. JPEG2000의 대표적 기술적인 특성으로는 무손실/손실 압축, 무손실 코딩에의 내포된 손실, 화소 정확성과 해상 등에 의한 진보적인 전달, 비트 에러 그리고 관심영역 부호화의 견고함 등이 있다. JPEG2000의 필요성이 강조되는 다양한 응용분야로는 인터넷, 컬러 팩스, 인쇄, 스캐닝, 디지털 사진, 원격 탐사, 이동식 적용, 의학 영상, 전자 도서관과 E-commerce 등이 있다.

• Journal of the Korean Society of Radiology
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• v.10 no.6
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• pp.395-401
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• 2016

Upper gastrointestinal series is a diagnostic test that X-ray passes through the stomach after administering contrast media such as barium or gastrografin. Upper gastrointestinal series with an advantage of no side effect except temporary constipation or abdominal pain has been widely used to diagnose diseases of the gastrointestinal system. However, image degradation and diagnostic accuracy frequently occurred when improper movement and breath control were carried out by lack of understanding the overall inspection process for the upper gastrointestinal series. The movie of the upper gastrointestinal series was made for improving inspection accuracy and image quality. The examinees encouraged to see the movie for waiting time before doing upper gastrointestinal series. In this study, image quality and diagnostic accuracy was examined for the effect of the movie about upper gastrointestinal series. 60 patients composed of each 10 people from 30s to 80s were selected randomly among both 2,940 examinees in 2014 and 3,076 examinees in 2015. Image quality was evaluated by the full width at half maximum of profile for each image using the Image J. The measurement of the full width at half maximum showed 0.208 mm and 0.133 mm for after and before seeing the movie. Thus it was verified that the movie education could improve the image quality and diagnostic accuracy for upper gastrointestinal series.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.371-379
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• 2019

The purpose of this study was to investigate the effect of the change in the X-ray condition on the entrance surface dose (ESD) and dose area product (DAP) in the cine imaging of coronary angiography (CAG), and to analyze the usefulness of the condition change on the dose relation and image quality by measuring and analyzing the Signal to Noise Radio (SNR) and Contrast to Nois Ratio (CNR) of the angiographic images taken by the Image J program. Data were collected from 33 patients (24 males and 9 females) who underwent CAG at this hospital from November 2017 to March 2018. In terms of imaging condition and data acquisition, the ESD and DAP of group A with a high tube current of 397.2 mA and group B with a low tube current of 370.7 mA were retrospectively obtained for comparison and analysis. For the SNR and CNR measurement and analysis via Image J, the result values were derived by substituting the obtained data into the formula. The correlations among ESD and DAP according to the change in the imaging condition, SNR, and CNR were analyzed by using the SPSS statistical analysis software. The relationships of groups A and B, having a difference in the imaging condition, mA, with ESD ($A:483.5{\pm}60.1$; $B: 464.4{\pm}39.9$) and DAP ($A:84.3{\pm}10.7$; $B:81.5{\pm}7$) were not statistically significant (p>0.05). In the relationships with SNR and CNR based on Image J, the SNR ($5.451{\pm}0.529$) and CNR ($0.411{\pm}0.0432$) of the images obtained via the left coronary artery (LCA) imaging of group B showed differences of $0.475{\pm}0.096$ and $-0.048{\pm}0.0$, respectively, from the SNR ($4.976{\pm}0.433$) and CNR ($0.459{\pm}0.0431$) of the LCA of group A. However, the differences were not statistically significant (p<0.05). In the SNR and CNR obtained via the right coronary artery (RCA) imaging, the SNR ($4.731{\pm}0.773$) and CNR ($0.354{\pm}0.083$) of group A showed increased values of $1.491{\pm}0.405$ and $0.188{\pm}0.005$, respectively, from the SNR ($3.24{\pm}0.368$) and CNR ($0.166{\pm}0.033$) of group B. Among these, CNR was statistically significant (p<0.05). In the correlation analysis, statistically significant results were shown in SNR (LCA) and CNR (LCA); SNR (RCA) and CNR (RCA); ESD and DAP; ESD and sec; DAP and CNR (RCA); and DAP and sec (p<0.05). As a result of the analyses on the image quality evaluation and usefulness of the dose change, the SNR and CNR were increased in the RCA images of the CAG obtained by increasing the mA. Based on the result that CNR showed a statistically significant difference, it is believed that the contrast in the image quality can be further improved by increasing the mA in RCA imaging.

• Applied Microscopy
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• v.33 no.3
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• pp.187-193
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• 2003

When electron microscope images and selected area diffraction patterns of crystalline materials are being compared, it is important to know for the rotation of the diffraction pattern with respect to the image caused by the magnetic lens in the Electron Microscope. A well-known method to determine this rotation is to use a test crystal of $MoO_3$. But this method of determination of the rotation angle contains an uncertainty of $180^{\circ}$. Thus one has to devise another way to eliminate this uncertainty. In this paper we present a new and simple method of determining this rotation without any complexity. The method involves a process of obtaining LACBED patterns of crystalline materials. For the J2010 electron microscope, the rotation is determined to be $180^{\circ}$ and this angle remains unchanged for changing of the magnification and the camera length.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.102-113
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• 2014

This paper suggests a novel hardware architecture of a real-time rectification which is to remove vertical parallax of an image occurred in the pre-processing stage of stereo matching. As an off-line step, Matlab Toolbox which was designed by J.Y Bouguet, was used to calculate calibration parameter of the image. Then, based on the Heikkila and Silven's algorithm, rectification hardware was designed. At this point, to enhance the precision of the rectified image, floating-point unit was generated by using Xilinx Core Generator. And, we confirmed that proposed hardware design had higher precision compared to other designs while having the ability to do rectification in real-time.

• Journal of Biosystems Engineering
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• v.31 no.5 s.118
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• pp.436-442
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• 2006

This research was conducted to design and develop a wired monitoring system for judging if sick or dead layers (SDL) exist in multi-tier layers battery (MLB) by machine vision, and to analyze its performance. In this study, 20 Brown Leghorn (Hi-Brown) layers aged 37 weeks old, were used as the experimental animals. The intensity of concern paid by layers on feed was over 90% during 5 minutes and 30 seconds after providing feed, and normal layers (NL) had been standing to take feed for that period. Therefore, in this study, the optimal judging time was set by this test result. The wired monitoring system developed was consisted of a driving device for carrying machine vision systems, a control program, a RS232 to RS485 convertor, an automatic positioning system, and an image capture system. An image processing algorithm was developed to find SDL in MLB by the processes of binary processing, erosion, expansion, labeling, and reckoning central coordinate of the captured images. The optimal velocity for driving unit was set up as 0.13 m/s by the test results for wired monitoring system, and the proximity switch was controlled not to be operated for 1.0 second after first image captured. The wired monitoring system developed was tested to evaluate the remote monitoring performance at lab-scale laying hen house. Results showed that its judgement success.ate on normal cage (without SDL) was 87% and that on abnormal cage (with SDL) was 90%, respectively. Therefore, it would be concluded that the wired monitoring system developed in this study was well suited to the purpose of this study.