• Title/Summary/Keyword: Active vision

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An Application of Active Vision Head Control Using Model-based Compensating Neural Networks Controller

  • Kim, Kyung-Hwan;Keigo, Watanabe
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.168.1-168
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    • 2001
  • This article describes a novel model-based compensating neural network (NN) model developed to be used in our active binocular head controller, which addresses both the kinematics and dynamics aspects in trying to precisely track a moving object of interest to keep it in view. The compensating NN model is constructed using two classes of self-tuning neural models: namely Neural Gas (NG) algorithm and SoftMax function networks. The resultant servo controller is shown to be able to handle the tracking problem with a minimum knowledge of the dynamic aspects of the system.

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3D Reconstruction System Using Active Mirror (움직이는 거울을 이용한 물체의 3차원 복원 시스템)

  • 김기범;장경호;정순기
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.10b
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    • pp.484-486
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    • 2001
  • 본 논문은 움직이는 거울을 사용하여 얻은 물체의 영상에서 물체의 3차원을 실시간에 복원하는 능동적 비전(active vision) 시스템을 제안한다. 거울을 사용한 기존의 스테레오 시스템에서는 거울들과 카메라가 고정되어 있어 물체의 부분적인 3차원 복원만이 가능한 반면, 제안하는 시스템은 거울에 의해 생성되는 두 개의 소실점을 이용함으로써 항상 실시간 카메라 보정이 가능하며, 간단하게 거울에 맺힌 영상들간의 대응점을 찾음으로써 물체의 3차원 복원이 가능하다.

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Implementation of Real-Time Post-Processing for High-Quality Stereo Vision

  • Choi, Seungmin;Jeong, Jae-Chan;Chang, Jiho;Shin, Hochul;Lim, Eul-Gyoon;Cho, Jae Il;Hwang, Daehwan
    • ETRI Journal
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    • v.37 no.4
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    • pp.752-765
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    • 2015
  • We propose a novel post-processing algorithm and its very-large-scale integration architecture that simultaneously uses the passive and active stereo vision information to improve the reliability of the three-dimensional disparity in a hybrid stereo vision system. The proposed architecture consists of four steps - left-right consistency checking, semi-2D hole filling, a tiny adaptive variance checking, and a 2D weighted median filter. The experimental results show that the error rate of the proposed algorithm (5.77%) is less than that of a raw disparity (10.12%) for a real-world camera image having a $1,280{\times}720$ resolution and maximum disparity of 256. Moreover, for the famous Middlebury stereo image sets, the proposed algorithm's error rate (8.30%) is also less than that of the raw disparity (13.7%). The proposed architecture is implemented on a single commercial field-programmable gate array using only 13.01% of slice resources, which achieves a rate of 60 fps for $1,280{\times}720$ stereo images with a disparity range of 256.

Face Tracking System using Active Appearance Model (Active Appearance Model을 이용한 얼굴 추적 시스템)

  • Cho, Kyoung-Sic;Kim, Yong-Guk
    • 한국HCI학회:학술대회논문집
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    • 2006.02a
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    • pp.1044-1049
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    • 2006
  • 얼굴 추적은 Vision base HCI의 핵심인 얼굴인식, 표정인식 그리고 Gesture recognition등의 다른 여러 기술을 지원하는 중요한 기술이다. 이런 얼굴 추적기술에는 영상(Image)의 Color또는 Contour등의 불변하는 특징들을 사용 하거나 템플릿(template)또는 형태(appearance)를 사용하는 방법 등이 있는데 이런 방법들은 조명환경이나 주위 배경등의 외부 환경에 민감하게 반응함으로 해서 다양한 환경에 사용할 수 없을 뿐더러 얼굴영상만을 정확하게 추출하기도 쉽지 않은 실정이다. 이에 본 논문에서는 deformable한 model을 사용하여 model과 유사한 shape과 appearance를 찾아 내는 AAM(Active Appearance Model)을 사용하는 얼굴 추적 시스템을 제안하고자 한다. 제안된 시스템에는 기존의 Combined AAM이 아닌 Independent AAM을 사용하였고 또한 Fitting Algorithm에 Inverse Compositional Image Alignment를 사용하여 Fitting 속도를 향상 시켰다. AAM Model을 만들기 위한 Train set은 150장의 4가지 형태에 얼굴을 담고 있는 Gray-scale 영상을 사용 하였다. Shape Model은 각 영상마다 직접 표기한 47개의 Vertex를 Trianglize함으로서 생성되는 71개의 Triangles을 하나의 Mesh로 구성하여 생성 하였고, Appearance Model은 Shape 안쪽의 모든 픽셀을 사용해서 생성하였다. 시스템의 성능 평가는 Fitting후 Shape 좌표의 정확도를 측정 함으로서 평가 하였다.

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Stereovision by Active Surface Model

  • Yokomichi, M.;Sugiyama, H.;Kono, M.
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1990-1993
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    • 2005
  • Stereovision is known to be one of the most important tools for robot vision systems. Previously, 2D active contour model has been applied to stereovision by defining the contour on the 3D space instead of image plane. However, the proposed model is still that of curve so that some complex shapes such as surfaces with high curvature can not be properly estimated because of occlusion phenomena. In this paper, the authors extend the curve model to the surface model. The surface is approximated by polygons and new energy function and its optimization method for surface estimation is proposed. Its effectiveness is examined by experiments with real stereo images.

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Evaluation of Two Robot Vision Control Algorithms Developed Based on N-R and EKF Methods for Slender Bar Placement (얇은막대 배치작업에 대한 N-R 과 EKF 방법을 이용하여 개발한 로봇 비젼 제어알고리즘의 평가)

  • Son, Jae Kyung;Jang, Wan Shik;Hong, Sung Mun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.4
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    • pp.447-459
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    • 2013
  • Many problems need to be solved before vision systems can actually be applied in industry, such as the precision of the kinematics model of the robot control algorithm based on visual information, active compensation of the camera's focal length and orientation during the movement of the robot, and understanding the mapping of the physical 3-D space into 2-D camera coordinates. An algorithm is proposed to enable robot to move actively even if the relative positions between the camera and the robot is unknown. To solve the correction problem, this study proposes vision system model with six camera parameters. To develop the robot vision control algorithm, the N-R and EKF methods are applied to the vision system model. Finally, the position accuracy and processing time of the two algorithms developed based based on the EKF and the N-R methods are compared experimentally by making the robot perform slender bar placement task.

Effect for the Social Worker's Organizational Citizenship Behavior of Value Congruence and Vision Sharing (사회복지조직의 비전공유와 가치일치가 종사자의 조직시민행동에 미치는 영향)

  • Lee, Yong-Jae
    • The Journal of the Korea Contents Association
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    • v.13 no.12
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    • pp.748-757
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    • 2013
  • This study analyzed on the effect worker's organizational citizenship behaviors of vision sharing and values congruence in social welfare organization. Analysis results are as follows: the higher the degree of a certificate of qualification of social welfare organization's worker and the position of organization have on active organizational citizenship behavior in social welfare organization. Most social welfare organization don't effort for vision sharing and values congruence in organization. Vision sharing and values congruence in social welfare organization result in actively organizational citizenship behaviors. Social welfare organization's purpose are to solve the social problem in communities. Therefore, the administrator of social welfare organization strive to share the vision of the organization with worker, and should pay more effort in the selection process for selecting the worker that matches with organization's value.

Effect of East-West pain treatment for Central Poststroke Pain on alleviation of pain and Rehabilitation (뇌졸중 후 중추성 통증 환자에 대한 동서협진이 진통과 재활에 미치는 영향)

  • Lee, Hyun-jong;Kim, Su-young;Lee, Sang-hoon;Seo, Dong-min;Lee, Doo-ik;Kim, Keun-sik;Lee, Jae-dong;Lee, Yun-ho;Yang, Hyung-in;Park, Jae-kyung;Choi, Do-young
    • Journal of Acupuncture Research
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    • v.20 no.2
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    • pp.42-49
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    • 2003
  • Purpose : In order to study the effectiveness of East-West pain treatment on central poststroke pain(CPSP), we evaluated its effect on alleviation of pain and rehabilitation of CPSP patients who were treated with eletroacupuncture and west pain treatment for four weeks. Methods : Twenty four patients diagnosed by their pain characteristics of central pain form stroke were treated with sympathetic nerve block, gabapentin, amitriptyline, and electroacupuncture for four weeks. Pain intensity through the visual analogue scale(VAS), and improvements of mobility and rehabilitation through the modified Barthel index(MBI) and Rankin scale(RS), respectively, before and after pain treatment were also assessed. Results : VAS pain scores were significantly improved from $7.7{\pm}1.7$ to $4.4{\pm}2.0$ with pain treatment(p<0.05). In accordance with improvement of ain scores, RS and MBI scores ere also improved from $2.88{\pm}0.95$ to $2.13{\pm}1.01$ and from $83.0{\pm}16.9$ to $94.7{\pm}9.5$(p<0.05), respectively, with pain treatment(p<0.05). Conclusions : It was suggested that the active pain treatment was contributed to the rehabilitation of CPSP patients, resulting in improvement of quality of life of CPSP patients. Futhermore, East pain treatment in combination with West pain treatment may be useful modality to alleviate CPSP.

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Efficient Tracking of a Moving Object using Optimal Representative Blocks

  • Kim, Wan-Cheol;Hwang, Cheol-Ho;Lee, Jang-Myung
    • International Journal of Control, Automation, and Systems
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    • v.1 no.4
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    • pp.495-502
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    • 2003
  • This paper focuses on the implementation of an efficient tracking method of a moving object using optimal representative blocks by way of a pan-tilt camera. The key idea is derived from the fact that when the image size of a moving object is shrunk in an image frame according to the distance between the mobile robot camera and the object in motion, the tracking performance of a moving object can be improved by reducing the size of representative blocks according to the object image size. Motion estimations using Edge Detection (ED) and Block-Matching Algorithm (BMA) are regularly employed to track objects by vision sensors. However, these methods often neglect the real-time vision data since these schemes suffer from heavy computational load. In this paper, a representative block able to significantly reduce the amount of data to be computed, is defined and optimized by changing the size of representative blocks according to the size of the object in the image frame in order to improve tracking performance. The proposed algorithm is verified experimentally by using a two degree-of- freedom active camera mounted on a mobile robot.

Classification of White Blood Cell Using Adaptive Active Contour

  • Theerapattanakul, J.;Plodpai, J.;Mooyen, S.;Pintavirooj, C.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1889-1891
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    • 2004
  • The differential white blood cell count plays an important role in the diagnosis of different diseases. It is a tedious task to count these classes of cell manually. An automatic counter using computer vision helps to perform this medical test rapidly and accurately. Most commercial-available automatic white blood cell analysis composed mainly 3 steps including segmentation, feature extraction and classification. In this paper we concentrate on the first step in automatic white-blood-cell analysis by proposing a segmentation scheme that utilizes a benefit of active contour. Specifically, the binary image is obtained by thresolding of the input blood smear image. The initial shape of active is then placed roughly inside the white blood cell and allowed to grow to fit the shape of individual white blood cell. The white blood cell is then separated using the extracted contour. The force that drives the active contour is the combination of gradient vector flow force and balloon force. Our purposed technique can handle very promising to separate the remaining red blood cells.

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