• 전기학회논문지
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• 제56권5호
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• pp.973-979
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• 2007

A laser vision system is developed to measure the three-dimensional feature of an object. This system consists of two low cost cameras and a cross laser. One camera and a cross laser are used to measure a plane equation of an object. Using this information, the other camera measures a hole size of an object. The proposed system provides 0.05 mm accuracy measurement systems with relatively low cost.

• KIEAE Journal
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• 제3권2호
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• pp.59-66
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• 2003

To be the design method supporting aesthetic ability of human, CAAD system should essentially recognize architectural form in the same way of human. In this study, visual perception process of human was analyzed to search proper computational method performing similar step of perception of it. Through the analysis of visual perception, vision was separated to low-level vision and high-level vision. Edge detection and neural network were selected to model after low-level vision and high-level vision. The 24 images of building, tree and landscape were processed by edge detection and trained by neural network. And 24 new images were used to test trained network. The test shows that trained network gives right perception result toward each images with low error rate. This study is on the meaning of artificial intelligence in design process rather than on the design automation strategy through artificial intelligence.

• Journal of Biosystems Engineering
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• 제23권5호
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• pp.481-490
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• 1998

A computer vision system to measure low flow rate of solid particles was developed and tested to examine its performance with various sized 7 kinds of seeds, perilla, mung bean, paddy, small red bean, black soybean, Cuba bean and small potato tuber. The test was performed for two types of particle flow, continuous and discontinuous. For the continuous flow tested with perilla, mung bean and paddy, the tests resulted correlation coefficients for the flow rates measured by the computer vision and direct method about 0.98. Average errors of the computer vision measurement were in a range of 6∼9%. For the discontinuous flow tested with small red bean, black soybean, Cuba bean and small potato tuber, the tests resulted correlation coefficients for the flow rates measured by the computer vision and direct method 0.98∼0.99. Average errors of the computer vision measurement were in a range of 5∼10%. Performance of the computer vision system was compared with that of the conventional optical sensor to count particles in discontinuous flow. The comparison was done with black soybean, Cuba bean and small potato tuber, and resulted that the computer vision has much better performance than the optical sensor in a sense of precision of the measurement.

• 제어로봇시스템학회논문지
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• 제17권6호
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• pp.546-551
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• 2011

Tilt sensor is required to control the attitude of the biped robot when it walks on an uneven terrain. Vision sensor, which is used for recognizing human or detecting obstacles, can be used as a tilt angle sensor by comparing current image and reference image. However, vision sensor alone has a lot of technological limitations to control biped robot such as low sampling frequency and estimation time delay. In order to verify limitations of vision sensor, experimental setup of an inverted pendulum, which represents pitch motion of the walking or running robot, is used and it is proved that only vision sensor cannot control an inverted pendulum mainly because of the time delay. In this paper, to overcome limitations of vision sensor, Kalman filter for the multi-rate sensor fusion algorithm is applied with low-quality gyro sensor. It solves limitations of the vision sensor as well as eliminates drift of gyro sensor. Through the experiment of an inverted pendulum control, it is found that the tilt estimation performance of fusion sensor is greatly improved enough to control the attitude of an inverted pendulum.

• 한국정보전자통신기술학회논문지
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• 제12권6호
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• pp.605-611
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• 2019

3D Vision system has many applications recently but popularization have many problems that need to be overcome. Volumetric display may process a amount of visual data and design the high efficient vision system for display. In case of stereo system for volumetric display, disparity vectors from the stereoscopic sequences and residual images with the reference images has been transmitted, and the reconstructed stereoscopic sequences have been displayed at the receiver. So central issue for the design of efficient volumetric vision system lies in selecting an appropriate stereo matching and robust vision system. In this paper, we propose high efficient vision system with the reduction of rectification error which can perform the 3D data extraction efficiently with low computational complexity. In experimental results with proposed vision system, the proposed method can perform the 3D data extraction efficiently with reducing rectification error and low computational complexity.

• 로봇학회논문지
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• 제18권1호
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• pp.66-71
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• 2023

As cameras have become primary sensors for mobile robots, vision based Simultaneous Localization and Mapping (SLAM) has achieved impressive results with the recent development of computer vision and deep learning. However, vision information has a disadvantage in that a lot of information disappears in a low-light environment. To overcome the problem, we propose an image enhancement method to perform visual SLAM in a low-light environment. Using the deep generative adversarial models and modified gamma correction, the quality of low-light images were improved. The proposed method is less sharp than the existing method, but it can be applied to ORB-SLAM in real time by dramatically reducing the amount of computation. The experimental results were able to prove the validity of the proposed method by applying to public Dataset TUM and VIVID++.

• ETRI Journal
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• 제30권6호
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• pp.783-789
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• 2008

A bio-inspired vision chip for edge detection was fabricated using 0.35 ${\mu}m$ double-poly four-metal complementary metal-oxide-semiconductor technology. It mimics the edge detection mechanism of a biological retina. This type of vision chip offer several advantages including compact size, high speed, and dense system integration. Low resolution and relatively high power consumption are common limitations of these chips because of their complex circuit structure. We have tried to overcome these problems by rearranging and simplifying their circuits. A vision chip of $160{\times}120$ pixels has been fabricated in $5{\times}5\;mm^2$ silicon die. It shows less than 10 mW of power consumption.

• 한국멀티미디어학회논문지
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• 제23권11호
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• pp.1418-1427
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• 2020

The web has become indispensable in all of our daily lives. We communicate, study and get information with others through the web. This behavior also continues in the smart phone environment. The biggest problem is that the small display screen of a smart phone degrades the accuracy in selecting or manipulating content for people with low vision. To compensate for this, voice guidance services that combine touch and voice, such as VoiceOver and Talkback, are currently provided to smart phone devices. However, restrictions arise in GUI, TTS control problems, and content expansion and selection. In addition, unnecessary content is also output by voice, which causes fatigue for low vision people to use. In this study, we propose a mobile web browser interface that selects and enlarges a desired area from web browsers and contents, or outputs it as a voice so that people with low vision can easily use the mobile web browser. In this paper, we propose a context selective focusing function that enables selection for each element of web content. In addition, we intend to develop a mobile voice web browser that can enlarge the selected content or output it by voice.

• 한국안광학회지
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• 제13권2호
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• pp.51-57
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• 2008

목적: 본 연구는 난시안의 교정 시 안정피로를 최소화하고 선명한 시생활 제공을 위한 적정 처방을 위해 최소착락원의 크기와 위치가 시력에 미치는 영향을 알아보고자 실시하였다. 방법: 경기도에 재학 중인 20대에서 40대 사이의 근시성 난시를 가지고 있는 남, 녀 대학생 68명(136 eye)을 대상으로 난시안의 최소착락원 크기와 위치에 따른 교정시력의 변화를 알아보기 위하여 난시를 완전교정한 후의 교정시력과 난시축은 변화를 주지 않고 난시량 만을 0.25D, 0.50D 감소한 상태의 시력, 난시량을 0.50D 저교정 함과 동시에 구면렌즈 -0.25D를 추가 장입했을 때의 시력을 측정하였다. 결과: 난시량의 교정상태에 따른 평균시력은 난시량을 완전교정했을 때 1.047이었고, 0.25D 저 교정 했을 때는 0.914, 0.50D 저교정했을 때는 0.772로 최소착락원이 클수록 시력감소폭이 컸으며, 난시안에서 교정시력은 최소착락원의 크기와 상관관계가 있다는 것을 알 수 있었다. 난시안에서 최소락원의 위치에 따른 평균시력은 난시량이 완전교정되어 점(point) 상태로 상이 망막위에 형성되었을 때는 1.047이었고, 난시량이 0.50D 저교정 상태 즉, 최소착락원이 망막 앞에 형성되었을 때는 0.772, 난시량이 0.50D를 저교정하고 최소착락원이 망막 위에 형성되었을 때는 0.828로 조사되었다. 즉, 난시량의 저교정 상태가 같을 경우 최소착락원 형태의 상이 망막 위에 형성 되었을 때가 망막 앞에 형성되었을 때 보다 시력감소가 적은 것으로 조사되었다. 결론: 난시안의 장용검사에서 원주렌즈 굴절력을 감소할 경우 최소착락원을 망막 위에 위치시키는 구면렌즈의 조정이 반드시 필요하다.

• 한국안광학회지
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• 제16권3호
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• pp.319-325
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• 2011

목적: 본 연구는 저시력과 가구 소득, 교육 수준 및 직업과 같은 사회경제적 요인과의 관련성을 평가하고자 하였다. 방법: 국민건강영양조사(2009년) 데이터를 이용하여 교정시력 검사를 받은 2,514명을 대상으로 가구소득, 교육수준, 직업에 따른 저시력의 유병률을 t-검정 및 $\chi^2$ 검정하였고, 대응위험도(odds ratio)를 측정하기 위하여 이분형 로지스틱 회귀분석을 이용하였다. 결과: 가구 소득, 교육수준, 직능 수준이 낮을수록 저시력 발생이 높은 것으로 나타났으며, 가구소득이 '하'인 경우 대응위험도는 2.77(95% CI, 1.72-4.47)이었고, 교육수준이 '초졸 이하'인 경우는 4.02(95% CI, 1.75-9.23)이었으며, 직업이 '무직'인 경우는 3.65(95% CI, 1.14-11.68)이었다. 결론: 사회적으로 저시력에 대한 관심이 필요하며, 정책적으로 저시력 환자들의 눈 건강형평성을 해소하기 위한 안 보건 교육, 안질환 조기발견을 위한 검진 사업, 저시력 보조기구 사용교육 등 폭넓고 세심한 지원 그리고 이를 위해 가능한 보건 정책이 개발되어야 할 것으로 생각된다.