• Title/Summary/Keyword: reference pixel

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Automatic Extraction Method of Control Point Based on Geospatial Web Service (지리공간 웹 서비스 기반의 기준점 자동추출 기법 연구)

  • Lee, Young Rim
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.2
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    • pp.17-24
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    • 2014
  • This paper proposes an automatic extraction method of control point based on Geospatial Web Service. The proposed method consists of 3 steps. 1) The first step is to acquires reference data using the Geospatial Web Service. 2) The second step is to finds candidate control points in reference data and the target image by SURF algorithm. 3) By using RANSAC algorithm, the final step is to filters the correct matching points of candidate control points as final control points. By using the Geospatial Web Service, the proposed method increases operation convenience, and has the more extensible because of following the OGC Standard. The proposed method has been tested for SPOT-1, SPOT-5, IKONOS satellite images and has been used military standard data as reference data. The proposed method yielded a uniform accuracy under RMSE 5 pixel. The experimental results proved the capabilities of continuous improvement in accuracy depending on the resolution of target image, and showed the full potential of the proposed method for military purpose.

A Study on Target Selection from Seeker Image of Aerial Vehicle in Sea Environment (해상 탐지 영상에서의 비행체 표적 선정에 관한 연구)

  • Kim, Ki-Bum;Baek, In-Hye;Kwon, Ki-Jeong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.5
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    • pp.708-716
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    • 2017
  • We deal with the target selection in seeker-detection image through network, using the detection information from aerial vehicle and the target information from surveillance and reconnaissance system. Especially, we constrain the sea battle environment, where it is difficult to perform scene-matching rather than land. In this paper, we suggest the target selection algorithm based on the confidence estimation with respect to distance and size. In detail, we propose the generation method of reference point for distance evaluation, and we investigate the effect of pixel margin and target course for size evaluation. Finally, the proposed algorithm is simulated and analyzed through several scenarios.

Estimation of Rotation Center and Rotation Angle for Real-time Image Stabilization of Roll Axis. (실시간 회전영상 안정화를 위한 회전중심 및 회전각도 추정 방법)

  • Cho, Jae-Soo;Kim, Do-Jong
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.153-155
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    • 2004
  • This paper proposes a real-time approach on the rotational motion estimation and correction for the roll stabilization of the sight system. This method first estimates a rotation center by the least-mean square algorithm based on the motion vectors of some feature points. And, then, a rotation angle is searched for a best matching block between a reference block image and seccessive input images using MPC(maximum pixel count) matching criterion. Finally, motion correction is performed by the bilinear interpolation technique. Various computer simulations show that the estimation performance is good and the proposed algorithm is a real-time implementable one to the TMS320C6415(500MHz) DSP.

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Mobile Robot Localization using Ceiling Landmark Positions and Edge Pixel Movement Vectors (천정부착 랜드마크 위치와 에지 화소의 이동벡터 정보에 의한 이동로봇 위치 인식)

  • Chen, Hong-Xin;Adhikari, Shyam Prasad;Kim, Sung-Woo;Kim, Hyong-Suk
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.4
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    • pp.368-373
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    • 2010
  • A new indoor mobile robot localization method is presented. Robot recognizes well designed single color landmarks on the ceiling by vision system, as reference to compute its precise position. The proposed likelihood prediction based method enables the robot to estimate its position based only on the orientation of landmark.The use of single color landmarks helps to reduce the complexity of the landmark structure and makes it easily detectable. Edge based optical flow is further used to compensate for some landmark recognition error. This technique is applicable for navigation in an unlimited sized indoor space. Prediction scheme and localization algorithm are proposed, and edge based optical flow and data fusing are presented. Experimental results show that the proposed method provides accurate estimation of the robot position with a localization error within a range of 5 cm and directional error less than 4 degrees.

Disparity-based Error Concealment for Stereoscopic Images with Superpixel Segmentation

  • Zhang, Yizhang;Tang, Guijin;Liu, Xiaohua;Sun, Changming
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.9
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    • pp.4375-4388
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    • 2018
  • To solve the problem of transmission errors in stereoscopic images, this paper proposes a novel error concealment (EC) method using superpixel segmentation and adaptive disparity selection (SSADS). Our algorithm consists of two steps. The first step is disparity estimation for each pixel in a reference image. In this step, the numbers of superpixel segmentation labels of stereoscopic images are used as a new constraint for disparity matching to reduce the effect of mismatching. The second step is disparity selection for a lost block. In this step, a strategy based on boundary smoothness is proposed to adaptively select the optimal disparity which is used for error concealment. Experimental results demonstrate that compared with other methods, the proposed method has significant advantages in both objective and subjective quality assessment.

Obtaining 3-dimensional shape of hybrid reflectance surfaces using indirect diffuse illumination (간접 확산 조명을 이용한 혼성반사 표면의 3차원 형상 취득)

  • 김태은;안호근;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.301-312
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    • 1996
  • A new approach is presented for recovering the 3-D shape from shading image. Photometric Stereo Method (PSM) is generally based on the direct illumination. In this paper, the reflectance function is derived by introduceing the indirect diffuse illumination in PSM and then applied to hybrid reflectance model which consists fo two components; the Lambertian reflectance and the speclar reflectance. Under the hybrid reflectance model and the indirect diffuse illumination circumstances, the 3-D shape of object can be recovered from the suface normal vector extracted from the surface roughness, the surface reflectance ratio, and the intensity value of a pixel. This method is rapid because of using the reference table and simplifies the restriction condition about the reflectance function existing in prior studies. The recovery efficiency in our method is better than that in prior studies. Also, this method is applied to various types of surfaces by defining general reflectance function.

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Defect Inspection of TFT-LCD Panel using 3D Modeling and Periodic Comparison (3차원 모델링과 반복비교를 통한 TFT-LCD 패널의 결점 검출)

  • Lee, Kyong-Min;Chang, Moon-Soo;Park, Poo-Gyeon
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.149-150
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    • 2007
  • In this paper, we propose a novel defects inspection algorithm for TFT-LCD panels. We first compensate the distorted image caused by the camera distortion and the uneven illumination environment using the least squares method and the bezier surface. We find a starting point of each pattern. The reference frame, made by subtract method using several clean patterns, is compared to each pattern to find defects. The simulation example shows that our algorithm not only inspects the defects well, but also is robust to the 1-pixel error.

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A Circuit Design of Fingerprint Authentication Sensor (지문인식센서용 회로설계)

  • 남진문;정승민;이문기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.4A
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    • pp.466-471
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    • 2004
  • This paper proposes an advanced circuit for fingerprint sensor signal processing. We increased the voltage between ridge and valley by modifying the parasitic capacitance eliminating circuit of sensor plate. The analog comparator was designed for comparing the sensor signal voltage with the reference signal voltage. 1-Pixel Fingerprint sensor circuit was designed and simulated, and the layout was performed.

High Performance Circuit Design of a Capacitive Type Fingerprint Sensor Signal Processing (고성능 용량 형 지문센서 신호처리 회로 설계)

  • 정승민;이문기
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.3
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    • pp.109-114
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    • 2004
  • This paper proposes an advanced circuit for the fingerprint sensor signal processing. We increased the voltage between ridge and valley by modifying the parasitic capacitance eliminating circuit of sensor plate. The analog comparator was designed for comparing the sensor signal voltage with the reference signal voltage. We also propose an effective isolation strategy for removing noise and signal coupling of each sensor pixel. The fingerprint sensor circuit was designed and simulated, and the layout was performed.

Target Positioning in Remote Area Using Strip Sensor Modeling of SPOT Imagery (SPOT 위성영상의 스트립 센서모델링을 이용한 비접근지역 위치결정 연구)

  • Kim, Man-Jo;Hwang, Chi-Jung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.2
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    • pp.155-160
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    • 2012
  • In this paper, a strip modeling method is developed for the acquisition of target positions in remote area and validated using the imagery of SPOT satellite. This method utilizes the parameters given in header files and constructs a camera model without ground control points. In most cases, the root mean squared error of check points is less than pixel size with one ground control point. The model error of reference image is evaluated using ground control points and used to remove the model error of target images acquired along the same satellite orbit, which enables one to calculate target positions in remote area where no ground control points are available.