• 한국멀티미디어학회논문지
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• 제24권4호
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• pp.558-568
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• 2021

The digital image to be accepted as legal evidence, it is important to verify the authentication of the digital image. This study proposes a method of authenticating digital images through three steps of comparing the file structure of digital images taken with iPhone, analyzing the encoding information as well as media logs of the iPhone storing the digital images. For the experiment, digital image samples were acquired from nine iPhones through a camera application built into the iPhone. And the characteristics of file structure and media log were compared between digital images generated on the iPhone and digital images edited through a variety of image editing tools. As a result of examining those registered during the digital image creation process, it was confirmed that differences from the original characteristics occurred in file structure and media logs when manipulating digital images on the iPhone, and digital images take with the iPhone. In this way, it shows that it can prove its forensic authentication in iPhone.

• 치과방사선
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• 제24권2호
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• pp.439-450
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• 1994

Recently, the digital image was introduced into radiological image. The digital image has the power of contrast enhancement, histogram control, and other digitally enhancement. At the point of the resolution, periapical radiograph is superior to the digital image, but enhanced digital procedure improves the diagnostic ability of the digital image. The purpose of this study was to evaluate the diagnostic ability of artificial proximal caries in conventional radiographs, digital radiographs and enhanced digital radiographs (histogram specification). ROC (Receiver Operating Characteristic) analysis and paired t-test were used for the evaluation of detectability, and following results were acquired: 1. The mean ROC area of conventional radiographs was 0.9274. 2. The mean ROC area of unenhanced digital image was 0.9168. 3. The mean ROC area of enhanced digital image was 0.9339. 4. The diagnostic ability of three imaging methods was not significant difference(p>0.05). So, the digital images had similar diagnostic ability of artificial proximal caries to conventional radiographs. If properly enhanced digital image, it may be superior to conventional radiographs.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.203-208
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• 2004

Recently, digital image is increasing greatly practical use degree in several industry fields including construction. And interest about 3D digital image that can express practical object realistically is augmented greatly. In this study, developed 3D digital image generation system based on digital photogrammetry and created 3D digital image for object. And, wished to verify of 3D digital image through comparative analysis with processing result by digital photogrammetry system been using much the latest for acquisition of 3D information. Also, wished to apply to surface information acquisition about rock slope and execute investigation about discontinuity of joint etc. As the result, could created 3D digital image for object using the 3D digital image generation system developing in this study, and acquire surface information about rock slope efficiently.

• 대한공간정보학회지
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• 제5권2호
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• pp.207-220
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• 1997

본 연구에서는 항공사진과 지형공간정보체계를 이용하여 수치영상지도를 제작하기 위한 효율적 방안을 고찰하고, 저가의 개인용 컴퓨터시스템을 기본으로 하는 지형공간정보체계를 이용하여 수치항공사진 영상과 수치지형도를 중첩함으로써, 지형판독성과 활용성이 높은 수치영상지도를 제작하는 실험적 방안을 연구한다. 이를 위하여 지상좌표의 결정, 수치영상처리, 수치표고모형의 생성에 대하여 고찰한 다음, 수치영상지도제작에 필요한 영상자료 입출력, 수치편위미분수정, 항공사진을 이용한 정사투영상의 생성에 관련된 방법을 고찰하고, 수치영상지도를 실험제작하여 그 활용방안을 제시하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.491-494
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• 1999

Introduction of digital communication network such as Integrated Services Digital Networks(ISDN) and digital storage media have rapidly developed. Due to a large amount of image data, compression is the key techniques in still image and video using digital signal processing for transmitting and storing. Digital image compression provides solutions for various image applications that represent digital image requiring a large amount of data. In this paper, the proposed DWT(Discrete Wavelet Transform) filter bank is consisted of simple architecture, but it is efficiently designed that a user obtain a wanted compression rate as only input parameter. If it is implemented by FPGA chip, the designed encoder operates in 12MHz.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.27-30
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• 2003

In this paper a new approach of digitalized ‘Takbon’ is introduced. By image signal processing, the letters which were written on stones can be deciphered. Epigraphic letter is detected by digital image device, digital camera. The two dimensional digital image is preprocessed because of sensor noise and detective turbulence. Color image is transformed into grey level. The letter image is analyzed in time/frequency domain. By the resultant analysis data decisive functions are calculated. Signal Processing techniques, such as scaling, clipping, digital negative, high/low filter, morphology and so on, provide algorithms that can extract letter from stones.

• 대한공간정보학회지
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• 제8권2호
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• pp.89-99
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• 2000

수치사진측량시스템(Digital Photogrammetry System)환경 내에서 일어나는 모든 작업은 수치영상을 기본 자료로 이용하게 되므로 수치영상의 품질과 정확도는 수치사진측량의 정확도를 좌우하는 중요한 요소 중에 하나이다. 그림에도 불구하고 현재까지는 수치사진측량 환경의 작업 수행 시 수치영상의 품질이나 정확도에 관한 명확한 기준이 설정되어 있지 않아 자료의 활용성 및 품질을 화보하기 어려운 실정이다. 본 연구에서는 수치사진측량을 이용하여 항공사진영상 데이터베이스를 구축할 경우 선행되어질 항공사진의 수치영상화시 최적해상도를 제시하고자 자동내부표정을 통하여 최적 해상도를 결정하였고, 다음으로 표정해석을 통하여 최적해상도를 검증 하고자 하였다. 그리고 앞서 결정된 최적해상도의 수치영상을 활용하여 정사투영영상이나, 모자이크영상을 제작함으로 그 타탕성을 입증 하고자 하였다.

• 한국인쇄학회지
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• 제22권2호
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• pp.163-178
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• 2004

In this study, the CIE RGB color space which was one of the most popular device-dependent application program in digital image processing was adopted to make the profile with the device information. The profile was applied to the digital image of a JPEG file format. The result was compared with the color reproduction of another digital image of a JPEG file format, which was made in the e-sRGB color space that had the color spaces allocated to each reproduced color of an image and device-independent colors. In this way it was investigated which color space was more appropriate for digital image processing for web printing and if the e-sRGB color space was good as a color management tool that didn't depend on a device in processing a digital image for web printing.

• 한국컴퓨터정보학회논문지
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• 제9권2호
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• pp.49-56
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• 2004

본 논문에서는 디지털 영상을 효과적으로 처리하기 위한 에지 클래스를 설계한다. 에지는 디지털 영상에서 물체를 검출하거나 인식하기 위한 핵심적인 형태정보를 포함하는 기초자료로 사용되는 중요한 정보이다. 그러므로 에지를 검출한 후 검출된 에지를 효과적으로 관리하고 다양한 응용이 가능하도록 하는 것은 디지털 영상 처리에 있어 매우 중요하다 기존의 디지털 영상 처리 시스템에서 사용되던 환경은 사용 편의성이나 속도 등의 측면에서 많은 한계점을 가지고 있다. 따라서 본 논문에서는 검출된 에지를 효과적으로 관리할 수 있는 에지 클래스를 설계하고, 이를 에지 검출 알고리즘을 이용하여 테스트해봄으로써 기존의 방법과 비교 분석해 본다.

• 치과방사선
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• 제29권2호
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• pp.387-396
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• 1999

In dentistry. RadioVisioGraphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter. many types of direct digital radiographic system have been produced in the last decade. They are based either on charge-coupled device(CCD) or on storage phosphor technology. In addition. new types of digital radiographic system using amorphous selenium. image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose. image processing, computer storage. electronic transfer of images and so on. Image processing includes image enhancement. image reconstruction. digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system(IMACS) for dentomaxillofacial radiology was reported in 1992. IMACS in dental hospital has been increasing. Meanwhile. researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible. feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis. have been performed actively in the last decade. Further developments in digital radiographic imaging modalities. image transmission system. imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.