A Study on the Contour-Preserving Image Filtering for Noise Removal

유충웅,유대현,배강열,Yoo, Choong-Woong,Ryu, Dae-Hyun,Bae, Kang-Yeul The Institute of Electronics and Information Engin 1999 電子工學會論文誌-T Vol.t36 No.4

In this paper, a simple contour-preserving filtering algorithm is proposed. The goal of the contour-preserving filtering method is to remove noise ad granularity as the preprocessing for the image segmentation procedure. Our method finds edge map and separates the image into the edge region and the non-edge region using this edge map. For the non-edge region, typical smoothing filters could be used to remove the noise and the small areas during the segmentation procedure. The result of simulation shows that our method is slightly better than the typical methods such as the median filtering and gradient inverse weighted filtering in the point of view of analysis of variance (ANOVA).

▽^2G 연산자를 이용한 참윤곽점 추출 및 연산속도 개선

유충웅 서라벌대학 1992 논문집 Vol.6 No.-

It is shown that ▽^2G operator can produce edges which do not correspond to significant image intensity changes. Such edges are called phantom. In this paper, a method for classifying zero-crossings as correspond to 'authentic' or "phantom" edges is present and a biased problems for computing the convolution of an image with ▽^2G masks.

윤곽점 추출을 위한 전방향성 알고리즘의 제안

劉忠雄 서라벌대학 1995 논문집 Vol.9 No.-

The Laplacian of Gaussian operator is one of the most popular operators in edge detection. This operator, however has some problems: all zero-crossings do not correspond to edges, zerocrossings do not accurately localize edges and also, located the dispiacement of edges. In this paper, to solve this problems, offer the 1st derivaties and 3rd derivatives using ▽^2G operator whichis proposed J.J. Clark. But Clark's method the derivatives for normal component dirction is not always solved in multi-step and slices intensity function and, each derivatives diffrs from Omni-directional Algorithms. This implemention always finds out edge point, it matchs to real. We also dicuss the problems of operating speed in the proposed methed using multiplication to find the displacement of egdes. And presented computer simulation for multi-step and slices intensity distribution on 1-D. test image.

액정 배향 방향성의 분포에 관한 연구

유충웅 서라벌대학 1997 논문집 Vol.12 No.-

Today, most of the liquid crystal displays produced use either the twisted nematic or supertwisted nematic electrooptical effects, This paper descrives a numerical methods by which we have computed the change in molecular orientation with time in TN cells when the applied field is changed, and tries to analyze the effect of deformation factor, the spray, twist, bend with non-zero pretilt angles at the boundaries as the continuum theory of the nematic state reported by F.C. Frank. And describes the energy density in the TN mode using an Euler-Laranger equations. These are different from the energy density equations and the analysis of the twist angle in the midlayer of the TN cells reported by P.A. Breddels and H.A. van Sprang. They solved the problems in the linear characteristics of the twist angle in the midlayer. More working needs the analysis the electrooptical dynamic characteristics of the TN and STN cells in liquid crystals.

연산자의 크기에 따른 윤곽점 추출

劉忠雄 서라벌대학 1994 논문집 Vol.8 No.-

An optimal method for edge detection is presented based on ∇^2G operator. The implementation differs marked for J.J.Clark as 1st, 3rd derivatives and offers the method of operator's magnitude. The zero-crossings obtained is not all edge, and these are grouped missing, displacement and authentication for complex image intensity and operator's magnitude. The main advantages of the proposed method lie in the simplicity of the choosing edge for the zero-crossings as scale space constant varies. The analysis is supported by the results of several experiments in simulation.

경주만의 관광기념품 개발에 관한 연구 - 경주 문화재를 소재로 한 마우스패드 시험적 제작 -

유충웅,이상덕 경주지역발전협의회 부설 경주발전연구원 2005 경주연구 Vol.13 No.-

색상보정 및 패턴 정합기법을 이용한 LCD 패턴검사에 관한 연구

예수영,유충웅,남기곤,Ye, Soo-Young,Yoo, Choong-Woong,Nam, Ki-Gon 한국융합신호처리학회 2006 융합신호처리학회 논문지 (JISPS) Vol.7 No.4

In this paper, we propose a method for the pattern inspection of LCD module using the color compensation and pattern matching. The pattern matching is generally used for the inspection method of LCD module at the industry. LCD module has many defections such as the brightness difference of the back light, the optic feature of liquid crystal, the difference of the light penetrated by driving LCD and the color difference by the lighting. The conventional method without the color compensation can not solve these defections and decreases the efficiency of inspecting LCD module. The method proposed to inspect defective badness through the pattern matching after it compensated color difference of the LCD occurred by the various causes. At first, it revises with setting by standard tone of color with the LCD pattern of the reference image. And It perform the preprocessing and pattern matching algorithm on the compensated image. In experiment, we confirmed that this algorithm is useful to detect some defections of LCD module. The proposed methods was easy to detect the faulty product. 본 논문에서는 LCD 조립이 완료된 제품에 대해 색상보정 기법을 이용한 LCD 패턴검사 방법을 제안하였다. 기존의 검사 시스템은 패턴 매칭에 의한 검사 기법을 많이 사용하고 있다. 이러한 방법은 LCD의 백라이트(back light) 장치의 휘도차이, 액정의 광특성, 구동특성에 의해 투과되는 빛의 차이, 주위 조명에 의한 색차 등을 보정 할 수 없으며, 또한 이로 인해 불량검출의 효율성을 저하시키는 원인이 된다. 제안하는 검사 방법은 다양한 원인에 의해 발생하는 LCD의 색상 차를 보정한 후 패턴 매칭을 통해 불량을 검출하는 방법이다. 먼저, 검사 대상인 LCD 패턴의 색상을 기준 영상에서 설정된 색상으로 보정한다. 색상이 보정된 영상은 다양한 전처리 기법을 적용하여 패턴 검사를 수행한다. 실험을 통하여 본 연구에서 제안한 알고리듬은 LCD 패널에서 여러 가지 불량품을 검출 할 수 있었고, 또한 제안된 방식은 기존의 방식과 비교하여 불량 검출이 용이함을 알 수 있었다.

관순법에 의한 휜-관 열교환기의 성능 해석

이태환,유충웅 진주산업대학교 1999 論文集 Vol.38 No.-

A cross-flow finned tube heat exchanger was investigated using a tube-by-tube method. The refrigerant R22 flows inside tubes while the air passes outside the finned tube. A self-constructed refrigerant circuitry was adopted. The refrigerant enthalpy at the exit of each tube and the average condensate layer thickness are investigated as a measure of the heat transfer and the observation with the quantity of condensation phenomenon respectively. The dependence of refrigerant enthalpy and the average condensate layer thickness on the refrigerant circuitry was also observed. It was confirmed that this method could be applied to the analysis of finned tube heat exchanger with condensation.

인간시각 체계를 이용한 가변 구획 절단 부호화

申容達,劉忠雄 서라벌대학 1993 논문집 Vol.7 No.-

본 논문에서는 인간 시각 체계를 이용한 가변 구획 절단 부호화를 제안하였다. 인간시각계의 민감한 영역에서 보일 수 있는 화질 열화를 줄이기 위해서 인간 시각 체계의 성질 및 표준절차를 결합하여 구획의 크기를 가변적으로 결정하였다. 컴퓨터 모의실험을 통하여 제안방법이 기존의 가변 구획 절단 부호화 방법보다 인간시각계의 민감한 영역에서 더욱 우수한 성능을 얻을 수 있었다. Variable block truncation coding(VBTC) using human visual system(HVS) is proposed. We used variable block size by combining HVS and standard deviation to reduce visible distortion at sensitive area in HVS. By computer simulation, we showed that the performance of proposed method was superior to that of the conventional VBTC.

PI 및 PD를 이용한 위치제어에 관한 연구

이철헌,유충웅 서라벌대학 1996 논문집 Vol.10 No.-

Control-system have made important contributions to our advancement in the 20th century. And PID controller is widely used in industrial automation system and chemical process, etc. We study on the controlling position system and propose the omptimizing algorithem using PI and PD method because it has less parameters and more stable than others. In this method, to fast control we decide to the coefficient of the system by measuring constant in the I/O interface. By this proposed method we improve the stability of the system response to the desired position controll.