• Title/Summary/Keyword: Lighting Compensation

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A Study on the Color Modelling Method for Color Picture Tube Color Display (CPT 색제시를 위한 색모델링 방법 연구)

  • 이응주
    • Journal of Korea Multimedia Society
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    • v.3 no.6
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    • pp.586-591
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    • 2000
  • Color pictures on CPT are generally affected by the receiver characteristic and the condition of exterior illuminants. Moreover, readjustment of incorrect color in the CPT causes color distortion on a given picture. This paper describes a color adjustment method for modelling of CPT at the view point of observer in the ordinary lighting condition. To develop this method, we proposed ways of luminance recompensation under the gamma transformation for the intensity of illuminant, hue/saturation compensation for the types of illuminant and control of specific color for the reference. Based on these method, a color correlation system is suggested with the goal of reducing the color errors which are represented due to the influence of reflectance component of illuminants, the gamma transformation of CPT and the frequently adjustment of reference scene to set a optimum color.

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Nucleus Recognition of Uterine Cervical Pap-Smears using Kapur Method and Fuzzy Reasoning Rule (Kapur 방법과 퍼지 추론 규칙을 이용한 자궁 경부진 핵 인식)

  • Kang, Kyoung-Min;Kim, Kwang-Baek
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.241-247
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    • 2007
  • 자궁 경부 세포진 영상의 핵 추출을 위해서는 영상의 배경과 핵 그리고 세포질 영역의 구분이 중요하다. 또한 정상 세포핵과 암종 세포핵의 구분 및 인식을 위해서는 세포핵들의 형태학적 특징을 이용한 분류 기준을 세워야한다. 본 논문에서는 자궁 경부 세포진 영상에서 세포핵의 후보 영역과 핵을 추출하기 위해 현미경 400배율 확대 사진을 획득하는 과정에서 훼손된 컬러 영상을 복원하기 위한 방법으로 Lighting Compensation을 적용하여 영상을 보정한다. 그리고 배경 영역과 세포핵 영역을 구분하기 위해 영상의 R,G,B 영역의 히스토그램의 분포를 이용하여 배경을 제거한다. 배경이 제거된 영상을 그레이 영상으로 변환 한 후, 히스토그램 명암도의 값을 이용하여 세포핵 영역과 세포질을 분류하여 세포핵 영역을 추출한다. 그리고 Kapur 방법을 적용하여 세포핵 영역의 엔트로피 누적확률을 구한 후, 영상을 이진화 한다. Kapur 방법이 적용된 이진화 영상에서 세포핵 영역의 중심과 주위 화소를 비교하는 $3\times3$ 마스크를 적용하여 영상의 미세한 잡음을 제거 한 후, 8방향 윤곽선 추적 알고리즘을 적용하여 최종적으로 세포핵 영역을 추출한다. 추출된 세포핵의 영역을 분류 및 인식하는 과정으로 세포의 외각의 방향성 정보, 핵의 크기, 그리고 면적 비율의 특징을 이용하여 퍼지 소속 함수를 설계한 후, 소속 함수의 소속도를 구하고 퍼지 추론 규칙을 적용하여 자궁 경부 세포진 영상에서 정상 세포핵 및 암종 세포핵을 인식한다.

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Skin Region Extraction Using Color Information and Skin-Color Model (컬러 정보와 피부색 모델을 이용한 피부 영역 검출)

  • Park, Sung-Wook;Park, Jong-Kwan;Park, Jong-Wook
    • 전자공학회논문지 IE
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    • v.45 no.4
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    • pp.60-67
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    • 2008
  • Skin color is a very important information for an automatic face recognition. In this paper, we proposed a skin region extraction method using color information and skin color model. We use the adaptive lighting compensation technique for improved performance of skin region extraction. Also, using an preprocessing filter, normally large areas of easily distinct non skin pixels, are eliminated from further processing. And we use the modified ST color space, where undesired effects are reduced and the skin color distribution fits better than others color space. Experimental results show that the proposed method has better performance than the conventional methods, and reduces processing time by $35{\sim}40%$ on average.

Research and development on image luminance meter of road tunnel internal and external (도로터널 내/외부의 영상휘도 측정기 연구개발)

  • Jang, Soon-Chul;Park, Sung-Lim;Ko, Seok-Yong;Lee, Mi-Ae
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.1
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    • pp.1-9
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    • 2015
  • This paper introduces the development of imaging luminance meter which measures the luminances of external/internal road tunnel. The developed imaging luminance meter complies with both L20 method and Veiling luminance method of the international standards, CIE88. In this paper the L20 method is mainly presented because most of tunnels currently adapt L20 method. The developed system has an embedded computer to operate at stand-alone. The system has a ethernet port, a heater, a fan, a defroster, a wiper and sun shielder. Compensation algorithm is applied for correcting non-linear responses to the luminance and integration time. The accuracy of measurement is less than 1% when it calibrated at the public certification institute. The developed system was also tested at the real field, road tunnel. The test results were very similar with the reference luminance meter and showed that the developed system operates well at the real field. Partial sensor saturations were happened to show the less luminance, because there were the high reflecting objects in the real field. Further study should be followed for high luminance measurement.

A study on measurement and compensation of automobile door gap using optical triangulation algorithm (광 삼각법 측정 알고리즘을 이용한 자동차 도어 간격 측정 및 보정에 관한 연구)

  • Kang, Dong-Sung;Lee, Jeong-woo;Ko, Kang-Ho;Kim, Tae-Min;Park, Kyu-Bag;Park, Jung Rae;Kim, Ji-Hun;Choi, Doo-Sun;Lim, Dong-Wook
    • Design & Manufacturing
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    • v.14 no.1
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    • pp.8-14
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    • 2020
  • In general, auto parts production assembly line is assembled and produced by automatic mounting by an automated robot. In such a production site, quality problems such as misalignment of parts (doors, trunks, roofs, etc.) to be assembled with the vehicle body or collision between assembly robots and components are often caused. In order to solve such a problem, the quality of parts is manually inspected by using mechanical jig devices outside the automated production line. Automotive inspection technology is the most commonly used field of vision, which includes surface inspection such as mounting hole spacing and defect detection, body panel dents and bends. It is used for guiding, providing location information to the robot controller to adjust the robot's path to improve process productivity and manufacturing flexibility. The most difficult weighing and measuring technology is to calibrate the surface analysis and position and characteristics between parts by storing images of the part to be measured that enters the camera's field of view mounted on the side or top of the part. The problem of the machine vision device applied to the automobile production line is that the lighting conditions inside the factory are severely changed due to various weather changes such as morning-evening, rainy days and sunny days through the exterior window of the assembly production plant. In addition, since the material of the vehicle body parts is a steel sheet, the reflection of light is very severe, which causes a problem in that the quality of the captured image is greatly changed even with a small light change. In this study, the distance between the car body and the door part and the door are acquired by the measuring device combining the laser slit light source and the LED pattern light source. The result is transferred to the joint robot for assembling parts at the optimum position between parts, and the assembly is done at the optimal position by changing the angle and step.

Hand Tracking and Hand Gesture Recognition for Human Computer Interaction

  • Bai, Yu;Park, Sang-Yun;Kim, Yun-Sik;Jeong, In-Gab;Ok, Soo-Yol;Lee, Eung-Joo
    • Journal of Korea Multimedia Society
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    • v.14 no.2
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    • pp.182-193
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    • 2011
  • The aim of this paper is to present the methodology for hand tracking and hand gesture recognition. The detected hand and gesture can be used to implement the non-contact mouse. We had developed a MP3 player using this technology controlling the computer instead of mouse. In this algorithm, we first do a pre-processing to every frame which including lighting compensation and background filtration to reducing the adverse impact on correctness of hand tracking and hand gesture recognition. Secondly, YCbCr skin-color likelihood algorithm is used to detecting the hand area. Then, we used Continuously Adaptive Mean Shift (CAMSHIFT) algorithm to tracking hand. As the formula-based region of interest is square, the hand is closer to rectangular. We have improved the formula of the search window to get a much suitable search window for hand. And then, Support Vector Machines (SVM) algorithm is used for hand gesture recognition. For training the system, we collected 1500 hand gesture pictures of 5 hand gestures. Finally we have performed extensive experiment on a Windows XP system to evaluate the efficiency of the proposed scheme. The hand tracking correct rate is 96% and the hand gestures average correct rate is 95%.

A Vehicle License Plate Recognition Using Intensity Variation and Geometric Pattern Vector (명암도 변화값과 기하학적 패턴벡터를 이용한 차량번호판 인식)

  • Lee, Eung-Ju;Seok, Yeong-Su
    • The KIPS Transactions:PartB
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    • v.9B no.3
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    • pp.369-374
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    • 2002
  • In this paper, we propose the react-time car license plate recognition algorithm using intensity variation and geometric pattern vector. Generally, difference of car license plate region between character and background is more noticeable than other regions. And also, car license plate region usually shows high density values as well as constant intensity variations. Based on these characteristics, we first extract car license plate region using intensity variations. Secondly, lightness compensation process is performed on the considerably dark and brightness input images to acquire constant extraction efficiency. In the proposed recognition step, we first pre-process noise reduction and thinning steps. And also, we use geometric pattern vector to extract features which independent on the size, translation, and rotation of input values. In the experimental results, the proposed method shows better computation times than conventional circular pattern vector and better extraction results regardless of irregular environment lighting conditions as well as noise, size, and location of plate.

Automatic Camera Pose Determination from a Single Face Image

  • Wei, Li;Lee, Eung-Joo;Ok, Soo-Yol;Bae, Sung-Ho;Lee, Suk-Hwan;Choo, Young-Yeol;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
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    • v.10 no.12
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    • pp.1566-1576
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    • 2007
  • Camera pose information from 2D face image is very important for making virtual 3D face model synchronize with the real face. It is also very important for any other uses such as: human computer interface, 3D object estimation, automatic camera control etc. In this paper, we have presented a camera position determination algorithm from a single 2D face image using the relationship between mouth position information and face region boundary information. Our algorithm first corrects the color bias by a lighting compensation algorithm, then we nonlinearly transformed the image into $YC_bC_r$ color space and use the visible chrominance feature of face in this color space to detect human face region. And then for face candidate, use the nearly reversed relationship information between $C_b\;and\;C_r$ cluster of face feature to detect mouth position. And then we use the geometrical relationship between mouth position information and face region boundary information to determine rotation angles in both x-axis and y-axis of camera position and use the relationship between face region size information and Camera-Face distance information to determine the camera-face distance. Experimental results demonstrate the validity of our algorithm and the correct determination rate is accredited for applying it into practice.

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Finding and Analysis of Defective Elements of an LED Streetlight Lamp Based on the Product Liability (PL에 근거한 LED 가로등의 결함 요소 발굴 및 분석)

  • Kim, Hyang-Kon;Choi, Chung-Seog
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.4
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    • pp.632-632
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    • 2009
  • The purpose of this study is to present the range of defects mentioned in the Product Liability (PL) and to establish an objective basis and grounds for the analysis of accidents expected to happen by analyzing and presenting the external flame pattern and electrical characteristics of an LED streetlight lamp, a new lighting lamp. From the analysis of the cross-section of a cable carbonized by an external flame, it was observed that the wire's strand and insulation material had solidly adhered, and that greater voids were formed at the surface than at the center. Irregular carbide lumps were formed in the globe directly exposed to the flame, and the globe carbonized by the indirect flame showed characteristics that they had melted and flowed downward. It was found that the forward and backward resistances of the normal LED were approximately 1.74 [$M{\Omega}$] and 140 [$M{\Omega}$], respectively. The lamp burnt by the strong flame exhibited infinite forward and backward resistances and the LED did not emit light. The carbonized LED lamp was gray and exhibited fine delaminations. According to the Product Liability, a product defect signifies a simple product defect. Most of the defects were caused by the lack of stability, and the defect of the product itself occurred during the design and manufacture. The defects in warnings and markings include an insufficiency of handling manuals and warnings, expressive warranty violations, defective markings, etc. In order to prevent an accident resulting from a product, it is necessary to prepare safety warnings and documentation, establish clear-cut lines of liabilities, and subscribe insurances. However, it could be seen that important factors against the Product Liability were product improvement, response to compensation requests and law suits, credit restoration, etc.

Sliding Active Camera-based Face Pose Compensation for Enhanced Face Recognition (얼굴 인식률 개선을 위한 선형이동 능동카메라 시스템기반 얼굴포즈 보정 기술)

  • 장승호;김영욱;박창우;박장한;남궁재찬;백준기
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.6
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    • pp.155-164
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    • 2004
  • Recently, we have remarkable developments in intelligent robot systems. The remarkable features of intelligent robot are that it can track user and is able to doface recognition, which is vital for many surveillance-based systems. The advantage of face recognition compared with other biometrics recognition is that coerciveness and contact that usually exist when we acquire characteristics do not exist in face recognition. However, the accuracy of face recognition is lower than other biometric recognition due to the decreasing in dimension from image acquisition step and various changes associated with face pose and background. There are many factors that deteriorate performance of face recognition such as thedistance from camera to the face, changes in lighting, pose change, and change of facial expression. In this paper, we implement a new sliding active camera system to prevent various pose variation that influence face recognition performance andacquired frontal face images using PCA and HMM method to improve the face recognition. This proposed face recognition algorithm can be used for intelligent surveillance system and mobile robot system.