• 한국방재학회:학술대회논문집
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• 한국방재학회 2011년도 정기 학술발표대회
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• pp.39-39
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• 2011

This study presents an effective vision-based system for cable bridge damage detection. In theory, cable bridges need to be inspected the outer as well as the inner part. Starting from August 2010, a new research project supported by Korea Ministry of Land, Transportation Maritime Affairs(MLTM) was initiated focusing on the damage detection of cable system. In this study, only the surface damage detection algorithm based on a vision-based system will be focused on, an overview of the vision-based cable damage detection is given in Fig. 1. Basically, the algorithm combines the image enhancement technique with principal component analysis(PCA) to detect damage on cable surfaces. In more detail, the input image from a camera is processed with image enhancement technique to improve image quality, and then it is projected into PCA sub-space. Finally, the Mahalanobis square distance is used for pattern recognition. The algorithm was verified through laboratory tests on three types of cable surface. The algorithm gave very good results, and the next step of this study is to implement the algorithm for real cable bridges.

• 한국분말재료학회지
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• 제24권4호
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• pp.285-291
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• 2017

We propose a custom analysis technique for the dark field (DF) image based on transmission electron microscopy (TEM). The custom analysis technique is developed based on the $DigitalMicrograph^{(R)}$ (DM) script language embedded in the Gatan digital microscopy software, which is used as the operational software for most TEM instruments. The developed software automatically scans an electron beam across a TEM sample and records a series of electron diffraction patterns. The recorded electron diffraction patterns provide DF and ADF images based on digital image processing. An experimental electron diffraction pattern is recorded from a IrMn polycrystal consisting of fine nanograins in order to test the proposed software. We demonstrate that the developed image processing technique well resolves nanograins of ~ 5 nm in diameter.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.395-398
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• 2003

Two component analysis methods based on the fuzzy relational calculus are proposed in the setting of the ordered structure. First component analysis is based on a decomposition of fuzzy relation into fuzzy bases, using gradient method. Second one is a component analysis based on the eigen fuzzy sets of fuzzy relation. Through experiments using the test images extracted from SIDBA and View Sphere Database, the effectiveness of the proposed component analysis methods is confirmed. Furthermore, improvements of the image compression/reconstruction and image retrieval based on ordered structure are also indicated.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.912-919
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• 2022

The study is an image-based assessment that uses image processing techniques to determine the condition of concrete with surface cracks. The preparations of the dataset include resizing and image filtering to ensure statistical homogeneity and noise reduction. The image dataset is then segmented, making it more suited for extracting important features and easier to evaluate. The image is transformed into grayscale which removes the hue and saturation but retains the luminance. To create a clean edge map, the edge detection process is utilized to extract the major edge features of the image. The Otsu method is used to minimize intraclass variation between black and white pixels. Additionally, the median filter was employed to reduce noise while keeping the borders of the image. Image processing techniques are used to enhance the significant features of the concrete image, especially the defects. In this study, the tonal zones of the histogram and its properties are used to analyze the condition of the concrete. By examining the histogram, the viewer will be able to determine the information on the image through the number of pixels associated and each tonal characteristic on a graph. The features of the five tonal zones of the histogram which implies the qualities of the concrete image may be evaluated based on the quality of the contrast, brightness, highlights, shadow spikes, or the condition of the shadow region that corresponds to the foreground.

• 한국멀티미디어학회논문지
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• 제22권8호
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• pp.860-873
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• 2019

LCD backlight boosting and the integration of boosting and dimming are proposed based on image analysis to maximize perceptual image qualities and to reduce display system power. Based on the histogram of the image data, methods for selecting an image suitable for boosting and for adjusting the optimum backlight brightness are proposed. A comprehensive combined optimization method of LCD backlight boosting, dimming and bypass based on image characteristics is also described. Perceptual image quality enhancement and power consumption are evaluated based on well known image databases. Average subjective image quality is improved by 24.8%, RMS contrast is improved more than 20%, and average power consumption is reduced by 15.94% compared to conventional uniform boosting.

• 융합신호처리학회논문지
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• 제12권1호
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• pp.33-37
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• 2011

본 논문은 FFT를 이용한 적외선 화재 열영상의 주파수 스펙트럼 분석에 관한 것으로 영상처리를 통하여 화재 발생 유무를 주파수 영역에서 판별하기 위한 조건을 도출하는 것이 목적이다. 적외선 열영상의 주파수 스펙트럼 분석은 고속 푸리에 변환을 이용하여 수행하였으며, 화재로 추정되는 고명도의 영역을 화재 후보영역으로 결정한 다음, 연속적인 열영상의 해당영역에 대하여 DC 및 AC 주파수 분포를 분석하였다. 분석된 결과를 기반으로 정적인 오검출 요소와 동적특성을 가지는 화재영역을 구분하는 열영상의 화재 판정 기준을 제시하고 컴퓨터 모의실험을 통하여 실용성을 확인하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.505-508
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• 2005

Wavelet scheme can be applied to the various remote sensing problems: conventional multi-resolution image analysis, compression of large image sets, fusion of heterogeneous sensor image and segmentation of features. In this study, we attempted wavelet-based filtering and its analysis. Traditionally, statistical methods and adaptive filter are used to manipulate noises in the image processing procedure. While we tried to filter random noise from optical image and radar image using Discrete Wavelet Transform (DW1) and Stationary Wavelet Transform (SW1) and compared with existing methods such as median filter and adaptive filter. In result, SWT preserved boundaries and reduced noises most effectively. If appropriate thresholds are used, wavelet filtering will be applied to detect road boundaries, buildings, cars and other complex features from high-resolution imagery in an urban environment as well as noise filtering

• 정보과학회 논문지
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• 제43권7호
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• pp.812-819
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• 2016

본 논문에서는 기존의 영상분할에서 발생하는 초기값 배정문제와 영상분할 가능여부를 확인할 수 있는 방법에 대한 이론적 근거를 분석하고 제시한다. 본 논문의 앞 부분에서는 위상수학의 이론에 근거한 수학적 논증을 바탕으로 적절한 초기값 배정의 대한 위상적 근거와 방법론을 제시한다. 이어서 위상수학의 분리공리 이론에 근거하여 영상이 영역 분할되기 위한 최소의 위상조건을 확인하고 해당 조건을 이용하여 영상분할을 위해 사용된 모델의 유효성을 검증하는 방법론을 제시한다. 즉, 본 논문은 기존의 통계적 분석과 달리, 위상적 분석을 통해 영상 영역 분할의 수학적 근거를 제시한 것에 그 특징이 있다. 마지막으로 기존의 가우시안 랜덤 필드 모델 기반 영상 분할에 본 논문에서 제시한 이론과 방법론을 적용하여 가우시안 랜덤 필드 모델의 유효성을 확인한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권3호
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• pp.1205-1223
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• 2018

Image enhancement is an emerging method for analyzing the images clearer for interpretation and analysis in the spatial domain. The goal of image enhancement is to serve an input image so that the resultant image is more suited to the particular application. In this paper, a novel method is proposed based on Mamdani fuzzy inference system (FIS) using multiple fuzzy membership functions. It is observed that the shape of membership function while converting the input image into the fuzzy domain is the essential important selection. Then, a set of fuzzy If-Then rule base in fuzzy domain gives the best result in image contrast enhancement. Based on a different combination of membership function shapes, a best predictive solution can be determined which can be suitable for different types of the input image as per application requirements. Our result analysis shows that the quality attributes such as PSNR, Index of Fuzziness (IOF) parameters give different performances with a selection of numbers and different sized membership function in the fuzzy domain. To get more insight, an optimization algorithm is proposed to identify the best combination of the fuzzy membership function for best image contrast enhancement.

• 대한원격탐사학회지
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• 제34권6_3호
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• pp.1427-1443
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• 2018

객체 기반 영상 분석은 영상의 복잡도를 낮추는 동시에 영상의 특성을 유지한다는 점에서 픽셀 기반 영상 분석보다 높은 효율성과 정보 활용 가능성을 지닌다. Superpixel은 일반적인 영상 분할보다 작은 영상 단위로 영상을 과분할함으로써 영상 내의 경계를 보다 잘 유지할 수 있다. 이 가운데 SLIC(Simple linear iterative clustering) superpixel 기법은 기존의 기법들보다 높은 품질의 영상 분할 결과를 제시하는 것으로 알려져 있다. 이러한 SLIC 기법의 입력 파라미터인 superpixel의 개수는 영상 분할 결과에 큰 영향을 미침에도 이에 대한 연구는 선행 연구에서 충분히 다루어지지 않았다. 이에 본 연구에서는 KOMPSAT 영상을 이용하여 변화 탐지 활용 연구를 위한 SLIC 계열 superpixel 기법의 최적 파라미터 분석 및 변화 탐지 성능 비교를 수행하였다. 사용된 superpixel 기법은 SLIC, SLIC0(SLIC의 무변수 버전), SNIC(Simple non-iterative clustering) 의 세 가지 기법으로, $5{\times}5$(픽셀)에서 $50{\times}50$(픽셀)의 superpixel 크기 범위에 대해서 superpixel 개수를 지정하여 superpixel 분할 영상을 생성하고 변화 탐지 참조 영상에 대한 재현율을 분석하였다. 이를 통해 얻어진 최적 superpixel 크기를 바탕으로 변화를 탐지하고자 하는 두 영상의 차 영상을 분할한 후 일정 크기의 객체로 clustering하였다. 두 시기(bi-temporal) 영상으로부터 얻어진 공통된 영상경계는 전후 영상에 각각 적용함으로써 각 superpixel의 feature(Lab 색상 차이) 변화를 탐지하였다. 최종적인 변화 탐지 결과는 참조 영상을 통해 그 성능이 분석하였으며, 영상의 과분할 정도가 높지 않더라도 규칙적인 크기와 형태의 superpixel을 통해 높은 변화 탐지 성능을 달성할 수 있음을 확인하였다.