• 한국멀티미디어학회논문지
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• 제4권1호
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• pp.29-36
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• 2001

본 논문에서는 회전 주사 패턴을 사용하여 영상 검색을 위한 효율적인 영상 기술 방법을 제안하였다. 본 논문에서 근회전 주사 패턴을 영상 중심부에 위치시키고, 이를 이용하여 공간 칼라 정보를 기술하였다. 사용된 특징은 회전 대표 칼라와 회전 칼라 질감 그리고 회전 칼라 변화도이다. 제안 방식은 영상의 색상 정보와 그와 관련된 국부적 공간 분포를 효율적으로 기술할 수 있었다. 따라서 위 방식은 영상 검색에 있어 기존방식에 비하여 계산량, 메모리 사용량 등을 줄일 수 있었다.

• 전자공학회논문지B
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• 제31B권7호
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• pp.9-15
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• 1994

This paper proposes a image compression algorithm which stores and transmites image data efficiently. The proposed compression algorithm modify enhances compression rate by modified ZIG-ZAG Scanning in JPEG standard algorithm which is based on 2D-DCT. And the up-compatible method of proposed algorithm can solve compatible problem with JPEG that is cased by modified ZIG-ZAG Scanning. And this paper presentes a block diagram of hardware for real-time processing.

• 한국BIM학회 논문집
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• 제6권4호
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• pp.18-26
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• 2016

Recently, for the purpose of maintenance of facilities and energy, there have been growing cases of the 3D image scan-based reverse design technology mostly in the manufacturing field. In the MEP field, because of differences between design and physical model, the reverse technology has been utilized in factory facilities such as a semiconductor factory. Because 3D point clouds from scanning include accurate 3D object information, the efficiency of management works related to the complex MEP facilities can be enhanced. In this study, the reverse technology was surveyed, and the MEP facility management based on 3D image scanning was analyzed. Based on the results, a method of 3D image scan-based MEP facility management was proposed.

• Progress in Superconductivity
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• 제11권2호
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• pp.128-134
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• 2010

The magnetic flux profiles in SmBCO and YBCO coated conductors(CC) in the presence of the external field were comparatively investigated by magneto-optic image and scanning hall probe measurements. The current distributions calculated by using the inversion method from measured field profiles show that the decrease of current densities near the edges of SmBCO CC is more significant than those of YBCO CC. Through the comparison of the numerical analysis based on Kim's critical state model and the Brandt and Indenbom's solution, we found that this feature is related to their different field dependant properties of the critical current densities.

• 한국터널지하공간학회 논문집
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• 제25권3호
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• pp.245-259
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• 2023

본 논문의 목적은 국내외 터널 스캐닝 시스템들을 분석하여 비접촉 이동식 상태점검 장비 개발에 대한 시사점을 도출하기 위한 것이다. 국내외 터널 스캐닝 시스템은 레이저 스캔과 이미지 스캔의 두 가지 기술로 개발되고 있다. 레이저 스캐닝 장비는 포인트 클라우드로부터 터널 라이닝의 기하하적 특성을 재현하는데 장점이 있다. 이미지 스캐닝 장비는 컴퓨터 비전을 활용하여 터널 라이닝 표면의 미세한 균열, 누수 등 손상 검출이 용이하다. 터널 라이닝의 손상 검출을 위해서는 이미지 스캐닝 장비가 더 적합할 것으로 분석되었다. 향후 개발 예정인 카메라 기반의 터널 스캐닝 시스템은 조명, 저장장치, 전원 공급 장치 및 차량 주행 속도 동기화 제어 장치로 구성되어야 할 것이다.

• Imaging Science in Dentistry
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• 제48권2호
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• pp.111-119
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• 2018

Purpose: This study was conducted to evaluate the accuracy of linear measurements of 3-dimensional (3D) images generated by cone-beam computed tomography (CBCT) and facial scanning systems, and to assess the effect of scanning parameters, such as CBCT exposure settings, on image quality. Materials and Methods: CBCT and facial scanning images of an anthropomorphic phantom showing 13 soft-tissue anatomical landmarks were used in the study. The distances between the anatomical landmarks on the phantom were measured to obtain a reference for evaluating the accuracy of the 3D facial soft-tissue images. The distances between the 3D image landmarks were measured using a 3D distance measurement tool. The effect of scanning parameters on CBCT image quality was evaluated by visually comparing images acquired under different exposure conditions, but at a constant threshold. Results: Comparison of the repeated direct phantom and image-based measurements revealed good reproducibility. There were no significant differences between the direct phantom and image-based measurements of the CBCT surface volume-rendered images. Five of the 15 measurements of the 3D facial scans were found to be significantly different from their corresponding direct phantom measurements(P<.05). The quality of the CBCT surface volume-rendered images acquired at a constant threshold varied across different exposure conditions. Conclusion: These results proved that existing 3D imaging techniques were satisfactorily accurate for clinical applications, and that optimizing the variables that affected image quality, such as the exposure parameters, was critical for image acquisition.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2529-2543
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• 2019

Scanning electron microscopy (SEM) image can link with the microscopic world through reflecting interaction between electrons and materials. The SEM images are easily subject to blurring distortions during the imaging process. Inspired by the fact that dark channel prior captures the changes to blurred SEM images caused by the blur process, we propose a method to evaluate the SEM images sharpness based on the dark channel prior. A SEM image database is first established with mean opinion score collected as ground truth. For the quality assessment of the SEM image, the dark channel map is generated. Since blurring is typically characterized by the spread of edge, edge of dark channel map is extracted. Then noise is removed by an edge-preserving filter. Finally, the maximum gradient and the average gradient of image are combined to generate the final sharpness score. The experimental results on the SEM blurred image database show that the proposed algorithm outperforms both the existing state-of-the-art image sharpness metrics and the general-purpose no-reference quality metrics.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.553-555
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• 2022

본 논문은 원샷 파노라믹 스캐닝을 기반으로 하는 실시간 자동 얼굴 인식 시스템에 대한 것이다. 한 번의 파노라믹 스캐닝 프로세스를 통하여 실시간으로 다수의 얼굴을 검출하고 사전에 등록된 얼굴을 인식하는 것이다. 한 장의 파노라마 영상 내에서 다수 얼굴 인식을 하는 것이 아닌, 스캐닝 과정에서 얻어진 다수의 영상을 이용하여 얼굴을 인식하도록 한다. 이는 파노라마 영상 생성 시간과 스티칭(Stitching) 오류를 줄임과 동시에 다수 영상의 누적 정보를 활용하여 얼굴 인식 성능을 향상할 수 있다. 이는 간단한 영상 획득 장치만으로 다수 인원의 스마트 출결 시스템과 같은 다양한 응용 프로그램에 사용될 수 있을 것으로 예상한다.

• 한국공작기계학회논문집
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• 제16권5호
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• pp.122-128
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• 2007

The electric part of thermal SEM(Scanning Electron Microscopy) consists of high voltage generation, lens control, and image processing. Several methodologies for enhancing SEM image are addressed and those results are verified through analyses and experiments. The controller employes a DSP(Digital Signal Processing), making the system more flexible and convenient than the classical analogue based controller. In some parts based the analog circuit, there are inevitable sources of noise and image distortion. The experimental investigation is provided along with analytical proof to enhance the SEM image.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.768-772
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• 2008

Various scanning systems have been studied in many industrial areas to acquire a range data or to reconstruct an explicit 3D model. Currently optical technology has been used widely by virtue of noncontactness and high-accuracy. In this paper, we describe a 3D laser scanning system developped to reconstruct the 3D surface of a large-scale object such as a curved-plate of ship-hull. Our scanning system comprises of 4ch-parallel laser vision modules using a triangulation technique. For multi laser vision, calibration method based on least square technique is applied. In global scanning, an effective method without solving difficulty of matching problem among the scanning results of each camera is presented. Also minimal image processing algorithm and robot-based calibration technique are applied. A prototype had been implemented for testing.