• Title/Summary/Keyword: visual measurement

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Automatic Visual Feature Extraction And Measurement of Mushroom (Lentinus Edodes L.)

  • Heon-Hwang;Lee, C.H.;Lee, Y.K.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.1230-1242
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    • 1993
  • In a case of mushroom (Lentinus Edodes L.) , visual features are crucial for grading and the quantitative evaluation of the growth state. The extracted quantitative visual features can be used as a performance index for the drying process control or used for the automatic sorting and grading task. First, primary external features of the front and back sides of mushroom were analyzed. And computer vision based algorithm were developed for the extraction and measurement of those features. An automatic thresholding algorithm , which is the combined type of the window extension and maximum depth finding was developed. Freeman's chain coding was modified by gradually expanding the mask size from 3X3 to 9X9 to preserve the boundary connectivity. According to the side of mushroom determined from the automatic recognition algorithm size thickness, overall shape, and skin texture such as pattern, color (lightness) ,membrane state, and crack were quantified and measured. A portion of t e stalk was also identified and automatically removed , while reconstructing a new boundary using the Overhauser curve formulation . Algorithms applied and developed were coded using MS_C language Ver, 6.0, PC VISION Plus library functions, and VGA graphic function as a menu driven way.

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A New Application of Human Visual Simulated Images in Optometry Services

  • Chang, Lin-Song;Wu, Bo-Wen
    • Journal of the Optical Society of Korea
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    • v.17 no.4
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    • pp.328-335
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    • 2013
  • Due to the rapid advancement of auto-refractor technology, most optometry shops provide refraction services. Despite their speed and convenience, the measurement values provided by auto-refractors include a significant degree of error due to psychological and physical factors. Therefore, there is a need for repetitive testing to obtain a smaller mean error value. However, even repetitive testing itself might not be sufficient to ensure accurate measurements. Therefore, research on a method of measurement that can complement auto-refractor measurements and provide confirmation of refraction results needs to be conducted. The customized optometry model described herein can satisfy the above requirements. With existing technologies, using human eye measurement devices to obtain relevant individual optical feature parameters is no longer difficult, and these parameters allow us to construct an optometry model for individual eyeballs. They also allow us to compute visual images produced from the optometry model using the CODE V macro programming language before recognizing the diffraction effects visual images with the neural network algorithm to obtain the accurate refractive diopter. This study attempts to combine the optometry model with the back-propagation neural network and achieve a double check recognition effect by complementing the auto-refractor. Results show that the accuracy achieved was above 98% and that this application could significantly enhance the service quality of refraction.

Studies on Visual Function Measurements for Building Visual Function Database of the Elderly (고령자의 시각기능데이터베이스 구축을 위한 시각기능계측에 관한 연구)

  • Kim, Dong-Wook;Park, Kwang-Suk;Kim, Jung-Ja;Kim, Nam-Gyun
    • Journal of Biomedical Engineering Research
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    • v.28 no.5
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    • pp.618-627
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    • 2007
  • As our society progresses rapidly toward an aged society, there is a stiff increase in the population of the aged persons who have difficulties in adjusting themselves to environments due to declines of their physical functions. Therefore, there is a great need for the concept of 'Universal Design' that demands the design of overall social structure to care for the elderly. Due to this reason, the physical function of the aged persons should thoroughly be studied for the development of rehabilitation and training equipments to help the recovery of physical functions of the elderly. Among the variety of physical functions of the elderly, visual functions, motion characteristics, hearing functions, and somatosensory functions have significant influence toward everyday lives and are physical functions to study for the construction of urgently needed physical function databases of the elderly. This study concentrates on visual functions among the variety of physical functions of the elderly. To measure various visual functions of the elderly, a measurement room for the elderly has been developed, which can mimic everyday lives and perform measurements of visual functions with subjects in seated position. The measurement items for the construction of the database were capabilities in everyday vision according to changes in arrangement of colors and light intensity and capabilities in everyday vision, color distinction, dark adaptation, and light glare against changes in contrast.

Changes in Visual Acuity and Values of Objective Refraction with Breath Alcohol Concentration (호흡 알코올 농도에 따른 시력과 타각적 굴절검사 값의 변화)

  • Jung, Su A;Nam, Soo-Kyung;Kim, Hyun Jung
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.2
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    • pp.187-193
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    • 2015
  • Purpose: This study was aimed to investigate effects of increased breath alcohol concentration (BrAC) which is the standard measurement of alcohol consumption in sobriety test under current laws on visual acuity and values of objective refraction. Methods: For twenty three males in 20s (average age $21.17{\pm}2.19$ years, body mass index (BMI) $22.09{\pm}2.16$) were selected. Distance and near visual test was performed at BrAC of 0%, 0.05% and 0.08%, and objective refraction with open-field auto-refractometer was also performed at different BrAC. Results: As breath alcohol concentration is increased, distance visual acuity was decreased, which was statistically significant, but near visual acuity was not changed. Also, values of objective refraction tended to be increased towards minus as breath alcohol concentration is increased. Conclusions: As breath alcohol concentration is increased, corrected visual acuity is decreased and refractive power is towards minus, it is necessary that visual acuity test and refraction measurement should be conducted under sober condition.

Apparatus and Method of Visual Lifetime Measurement of Organic Light Emitting Devices

  • Yang, Yong-Suk;Chu, Hye-Yong;Oh, Ji-Young;Lee, Jeong-Ik;Kim, Gi-Heon;KoPark, Sang-He;Hwang, Chi-Sun;Kim, Mi-Kyung;Do, Lee-Mi;Chung, Sung-Mook;Ko, Young-Wook
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.623-624
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    • 2004
  • The coating and estimation of gas and moisture barriers on polymer and glass substrates are receiving very much attention in passivation of organic light emitting devices (OLEDs). In this study, the encapsulation and lifetime measurement techniques of OLEDs were presented. The degradation mechanisms of bare and encapsulated OLEDs were investigated by the visual lifetime measurement (VLM) system with the parameters such as a pixel luminance(L), a luminance rms roughness(dL), a brightness area ratio(R), an edge degradation depth(D), etc.

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Development of Automatic Visual Inspection for the Defect of Compact Camera Module

  • Ko, Kuk-Won;Lee, Yu-Jin;Choi, Byung-Wook;Kim, Johng-Hyung
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2414-2417
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    • 2005
  • Compact Camera Module(CCM) is widely used in PDA, Celluar phone and PC web camera. With the greatly increasing use for mobile applications, there has been a considerable demands for high speed production of CCM. The major burden of production of CCM is assembly of lens module onto CCD or CMOS packaged circuit board. After module is assembled, the CCM is inspected. In this paper, we developed the image capture board for CCM and the imaging processing algorithm to inspect the defects in captured image of assembled CCMs. The performances of the developed inspection system and its algorithm are tested on samples of 10000 CCMs. Experimental results reveal that the proposed system can focus the lens of CCM within 5s and we can recognize various types of defect of CCM modules with good accuracy and high speed.

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Human Sensibility Measurement or the Visual Picture Stimulus (장면 시자극에 대한 감성측정에 관한 연구)

  • Kim, D.S.;Kim, D.Y.;Lim, Y.H.;Shon, J.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.23-26
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    • 1997
  • We present several biosignal measurement results and analysis algorithms or the visual stimulus from International Affective Picture System. Since human body is nonlinear dynamic system, we investigated both linear and nonlinear methods. We found that the chaos was diminished when unpleasant picture is presented relative to pleasant picture, and the alpha wave of EEG was slightly augmented in pleasant picture, but was not convincing result. These can be used as the parameter or the measurement of human sensibility.

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Measurement of Electrical Treeing Length and Area by Use of Image Processing (영상 처리 방법을 이용한 트리 길이와 열화면적 계측)

  • 백관현;김재환
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.8 no.1
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    • pp.57-62
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    • 1994
  • In this paper, a system for measuring of treeing degradation in organic dielectric material by using image processing technics, is discussed. Traditionally, treeing is measured by visual method. It made difficulty to understanding for features and changes in the configlEation of the tree growth. Using image processing system, it is made to describe the characters of the tree growth, specially length of tree and area of treeing degradation. From this image processing and visual measurement, the similar results were made, an automatic measurement system was made for configuration of the tree growth.

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A Study on the Correlation beween Visual Excess and Height Measuring Precision (과고감과 표고측정정밀도와의 상관관계에 관한 연구)

  • 최재화;운홍식
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.4 no.2
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    • pp.10-26
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    • 1986
  • In a stereoscopic measurements on the aerial photogrammetric works, it is in general understood that the larger and the larger is a vertical scale exaggeration, the better and the better is height measuring precision. Despite the success with which a stereoscopic measurement has been applied to contour mapping as well as spot height measurement, no generally accepted theory for visual excess has yet been developed. This experiments aim at arrangement of a correlation between visual excess and height measuring precision. The stereoscopic measurements with parallax bar in the mirror stereoscope are carried out on the test model of which consists normal angle, wide angle and super wide angle respectively. With the result of this experiments, it is conclued that height measuring precision is proportional to the magnitude of visual excess.

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