• Title/Summary/Keyword: 복원영상

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A Study on pipelines of a media content production based on digital reconstruction (디지털 복원에 기반한 영상콘텐츠 프로덕션의 파이프라인 연구 -카이스트 문화기술연구센터 디지털 헤리티지 그룹의 사례연구를 중심으로-)

  • Choi, Yang-Hyun;Kim, Tak-Hwan
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.1257-1264
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    • 2009
  • In regard to media contents of digital heritage reconstruction, they are actively produced in museums, art galleries and special exhibitions. However, there is no concrete guideline for the productions and the pipelines are not systematic either. This makes the process ineffective regarding time and cost. Media contents production of digital heritage reconstruction might seem similar to film or documentary production, but it is important to construct its specific pipeline based on its specific purpose. The digital Heritage group in research center for culture technology of KAIST produced media contents which digitally reconstructed various heritages such as Persepolis, Iranian remains, with National museum of Korea, Sukgulam, and Hue, an ancient city in Vietnam, with Cultural heritage administration of Korea. From these experiences and case studies, this paper will present a pipeline model for efficient production.

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Analysis Technique for Moving Targets on Single-Channel Airborne FMCW-SAR Image (항공기 기반 단일채널 FMCW-SAR 영상 내 이동물체 분석기법)

  • Hwang, Ji-hwan;Kim, Duk-jin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.7
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    • pp.523-531
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    • 2018
  • An analysis technique for detecting moving targets on a single-channel airborne frequency-modulated continuous-wave (FMCW) technology and synthetic aperture radar (SAR) image is presented. To analyze the relative velocities of moving targets, an FMCW-based signal model for stationary and moving targets was studied, and a SAR ambiguity function considering its signal model was simulated. The relative velocities of the moving targets on a reconstructed SAR image can be estimated by peak searching of the SAR ambiguity function, and the stationary and moving targets are easily distinguished when there is a large variation of the relative velocity. Analysis results of the moving targets on a reconstructed FMCW-SAR image, using practical airborne data and a SAR ambiguity process, are compared with the in situ testing in the study area.

Dynamical Electrical Impedance Tomography Based on the Regularized Extended Kalman Filter (조정 확장 칼만 필터를 이용한 동적 전기 임피던스 단층촬영법)

  • Kim, Kyung-Youn;Kim, Bong-Seok;Kang, Suk-In;Kim, Min-Chan;Lee, Jung-Hoon;Lee, Yoon-Joon
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.38 no.5
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    • pp.23-32
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    • 2001
  • Electrical impedance tomography (EIT) is a relatively new imaging modality in which the resistivity (conductivity) distribution of the unknown object is estimated based on the known sets of injected currents and measured voltages on the surface of the object. In this paper, we propose a dynamical EIT reconstruction algorithm based on the regularized extended Kalman filter(EKF). The EIT inverse problem is formulated as dynamic equation which consists of the slate equation and the observation equation, and the unknown state(resistivity) is estimated recursively with the aid of the EKF. In doing so, the generalized Tikhonov regularization technique is employed in the cost functional to mitigate the ill-posedness characteristics of the inverse problem. Computer simulations for the 16-channel synthetic data are provided to illustrate the reconstruction performance of the proposed algorithm.

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Enhancement of Image Reconstruction Using Region of Interest Method Based on Adaptive Threshold Value in Electrical Impedance Tomography (전기 임피던스 단층촬영법에서 적응 문턱치 기반의 관심영역 기법을 사용한 영상 복원의 개선)

  • Kim, Chang Il;Kim, Bong Seok;Kim, Kyung Youn
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.8
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    • pp.99-106
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    • 2017
  • Electrical impedance tomography is a nondestructive imaging modality in which the internal resistivity distribution is reconstructed based on the injected currents and measured voltages inside a domain of interest. In this paper, an adaptive threshold value based region of interest (ROI) method is proposed to improve the spatial resolution of reconstructed images as well as to reduce the computational time of the inverse problem. Adaptive threshold value is calculated by INTERMODES method and ROI is determined from the domain based on this value. Moreover, the computational domain of image reconstruction is restricted within a ROI and iterative Gauss-Newton method is employed to estimate the resistivity distribution. To evaluate the performance of the proposed method, numerical experiments have been performed and the results are analyzed.

The Technique of Blocking Artifacts Reduction Method Based on Spatially Adaptive Image Restoration (공간 적응적 영상복원을 이용한 블록화 현상 제거 기법)

  • Kim, Tae-Keun;Woo, Hun-Bae;Paik, Joon-Ki
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.12
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    • pp.46-54
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    • 1998
  • In this paper we propose a fast adaptive image restoration filter using DCT-based block classification for reducing block artifacts in compressed images. In order to efficiently reduce block artifacts, edge direction of each block is classified by using the DCT coefficients, and the constrained least square (CLS) on the observation that the quantization operation in a series of coding process is a nonlinear and many-to-one mapping operator. And then we propose an approximated version of constrained optimization technique as a restoration process for removing the nonlinear and space-varying degradation operator. For real-time implementation, the proposed restoration filter can be realized in the form of a truncated FIR filter, which is suitable for postprocessing reconstructed images in HDTV, DVD, or video conference systems.

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A Fast Fractal Image Decoding Using the Minimizing Method of Domain Region by the Limitation of Searching Regions (탐색영역 제한에 의한 정의역 최소화 기법을 이용한 고속 프랙탈 영상복원)

  • 정태일;강경원;문광석;권기룡;김문수
    • Journal of the Institute of Convergence Signal Processing
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    • v.2 no.2
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    • pp.13-19
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    • 2001
  • The conventional fractal decoding was required a vast amount computational complexity, since every range blocks was implemented to IFS(iterated function system). In order to improve this, it has been suggested that each range block was classified to iterated and non-iterated regions. Non-iterated regions is called data dependency region, and if data dependency region extended, IFS regions are contractive. In this paper, a searched region of the domain is limited to the range regions that is similar with the domain blocks, and the domain region is more overlapped. As a result, data dependency region has maximum region, that is IFS regions can be minimum region. The minimizing method of domain region is defined to minimum domain(MD) which is minimum IFS region. Using the minimizing method of domain region, there is not influence PSNR(peak signal-to-noise ratio). And it can be performed a fast decoding by reducing the computational complexity for IFS in fractal image decoding.

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A Study on Stereo Visualization of the X-ray Scanned Image Based on Dual-line Sensors (듀얼센서 기반 X-선 검색영상 스테레오 가시화 연구)

  • Lee, Nam-Ho;Hwang, Young-Gwan;Park, Jong-Won;Lim, Yong-Gon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.9
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    • pp.2083-2090
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    • 2010
  • This paper presents a 3-D visualization technique using stereo radioactive images to provide efficient inspection of fast moving cargo objects. The proposed technique can be used for such objects which CT or MRI cannot inspect due to restricted scan environment. Stereo radioactive images are acquired from a specially designed equipment which consists of a X-ray source, linear radioactive sensors, and a moving stage. Two radioactive sensors are installed so that rectified stereo X-ray images of objects are acquired. Using the stereo X-ray images, we run a matching algorithm to find the correspondences between the images and reconstruct 3-D shapes of real objects. The objects are put in a parallelepiped box to simulate cargo inspection. Three real objects are tested and reconstructed. Due to the inherent ambiguity in the stereo X-ray images, we reconstruct 3-D shapes of the edges of the objects. The experimental results show the proposed technique can provide efficient visualization for cargo inspection.

Adaptive Weight Filter Algorithm for Restoration Images Corrupted by High Density Impulse Noise (고밀도 임펄스 잡음에 훼손된 영상 복원을 위한 적응형 가중치 필터 알고리즘)

  • Cheon, Bong-Won;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.10
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    • pp.1483-1489
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    • 2022
  • Recently, due to the influence of the 4th industrial revolution and the development of communication media, various digital video equipment are being used in industrial fields. Image data is easily damaged by noise in the process of acquiring and transmitting and receiving from the camera and sensor, and since the damaged image has a great effect on the processing of the system, noise removal is essential. In this paper, a weight filter algorithm using a weight graph is proposed to restoration images damaged by high-density impulse noise. The proposed algorithm obtains a weight graph using pixel values inside the filtering mask of the image, and restores the image by applying the final weight to the filtering mask. Simulation was conducted to analyze the noise removal performance of the proposed algorithm, and the magnified image and PSNR were used to compare with the existing method. The resulting image of the proposed algorithm showed excellent performance by removing high-density impulse noise.

Online Image Reconstruction Using Fast Iterative Gauss-Newton Method in Electrical Impedance Tomography (전기 임피던스 단층촬영법에서 빠른 반복적 가우스-뉴턴 방법을 이용한 온라인 영상 복원)

  • Kim, Chang Il;Kim, Bong Seok;Kim, Kyung Youn
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.4
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    • pp.83-90
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    • 2017
  • Electrical impedance tomography is a relatively new nondestructive imaging modality in which the internal conductivity distribution is reconstructed based on the injected currents and measured voltages through electrodes placed on the surface of a domain. In this paper, a fast iterative Gauss-Newton method is proposed to increase the spatial resolution as well as reduce the inverse computational time in the inverse problem, which could be applied to online binary mixture flow applications. To evaluate the reconstruction performance of the proposed method, numerical experiments have been carried out and the results are analyzed.

Implementation of incoherent triangular holography and numerical reconstruction of the complex hologram (인코히어런트 삼각 홀로그래피의 구현과 복소홀로그램의 수치적 복원)

  • 김수길;이병호;김은수;손정영
    • Korean Journal of Optics and Photonics
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    • v.8 no.2
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    • pp.99-106
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    • 1997
  • In this paper, we demonstrated, through experiment and numerical reconstruction, that the bias and the conjugate image, which are main drawbacks in incoherent holography, can be removed. By using wave plates of the modified triangular interferometer, which was made by adding simple passive devices to the conventional triangular interferometer, we adjusted the relative phase differences of two optical waves traveling in clockwise and counterclockwise. In this way, we obtained four intensity patterns, and then by manipulating the four intensity patterns electronically we obtained the complex hologram without bias and the conjugate image. Comparing numerical reconstruction results of the complex hologram with numerical reconstruction results of the hologram obtained from the conventional triangular interferometer, we demonstrated that bias and the conjugate image can be removed using the modified triangular interferometer.

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