• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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• pp.106-109
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• 2003

This paper presents a hue preserving gamut mapping algorithm for color monitor and printer. The gamuts of monitor and printer are set by the profile of color reproduction media, specified by ICC(International Color Consortium) and provided by vendors, then those gamuts are represented on the CIE xy color space. In case that the color of monitor are located on out-of-gamut of printer, these are clipped on the point of gamut boundary of printer towards a reference white point. On the other hand, colors are in-gamut of printer are unchanged. An image generated by the algorithm keeps a ratio of each pixel of original image. Advantages of the algorithm are easy to implement and fast processing time than other algorithms which involve hue preserving especially in CIELAB color space.

• 한국인쇄학회지
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• 제23권1호
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• pp.13-25
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• 2005

In order to technical analysis of the Newspaper printing press, the printability such as, dot gain, contrast and printing density change according to the amount of ink and damping water feeding were experimented. t도 Printability assurance in printing aims at a correct and constant color reproduction throughout the whole print-run. And the checked values were checked from densitometer and colorimeter instead of conventional subjective method. In this research, we could propose the range of driving in printing of domestic Newspaper printing press as well as the limits of ink feed speed and damping water feed speed.

• 디지털융복합연구
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• 제5권2호
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• pp.155-165
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• 2007

The meaning of images are changed rapidly by a time, and the images' social function and skills are different by times. Nowadays, the reasons to have different meanings of images are the different ways of representation and reproduction of images by new digital technologies. However, the images are communicating with each other, and the image makers should have responsibility to represent the images. Also, the images should be concerned in social, cultural context, and focused on positive ways to represent. It is hard to predict the future of images, but people shouldn't be controled by manipulated digital images. Therefore, image makers need to have right ethics and morals in digital era not to be controled by commercial enterprises.

• 한국산업정보학회논문지
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• 제6권1호
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• pp.39-47
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• 2001

A blocked zerotree coding algorithm for compression of subband image is proposed. Significance of blocks with respect to a certain threshold are coded with a set of transition rules for the significance of blocks. Significant blocks are quantized by vector quantization. The basic idea for this coding approach are: 1) Subband images are coded by blocks, 2) Important blocks based on the significance of blocks are coded and quantized, 3) Multiband codebook which is composed of sub-codebooks dedicated for each threshold and subband level is adapted to produce good reproduction vectors for vector quantization. The compression results are similar to Shapiro's zerotree coding even though ours are obtained without entropy coding of bit streams from blocked zerotree encoder. If an entropy coding is applied to the bitstream, PSNR will be improved.

• Asia pacific journal of information systems
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• 제31권3호
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• pp.335-357
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• 2021

As reproduction of images can be done with ease, copy detection has increasingly become important. In the duplication process, image modifications are likely to occur and some alterations are deliberate and can be viewed as attacks. A wide range of copy detection techniques has been proposed. In our study, content-based copy detection, which basically applies DCT-based features for images, namely, pixel values, edges, texture information and frequency-domain component distribution, is employed. Experiments are carried out to evaluate robustness and sensitivity of DCT-based features from attacks. As different types of DCT-based features hold different pieces of information, how features and attacks are related can be shown in their robustness and sensitivity. Rather than searching for proper features, use of robustness and sensitivity is proposed here to realize how the attacked features have changed when an image attack occurs. The experiments show that, out of ten attacks, the neural networks are able to detect seven attacks namely, Gaussian noise, S&P noise, Gamma correction (high), blurring, resizing (big), compression and rotation with mostly related to their sensitive features.

• 대한인간공학회지
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• 제7권2호
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• pp.23-30
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• 1988

The methods suggested up to now for 3-dimensional anthroponetry require much efforts and costs in measuring and analysing. To solve these problems, we adopt the methods such as Moire Interferometry, Image processing and Computer Vision Technique which are efficient in processing anthropomorphic data. Moire contourgraph was constructed by using Ar-ion laser as a light source (2 Watt power and 5145 A wavelength) and laser beam expander(20X). Image data can be 3-dimensionally reconstructed as the surface patch and geographical relation between faces expressed by mash-point and edges as units. This research is focused on the followings; 1) Development of an economical and reliable measuring method. 2) Design of reproduction methods of 3-dimensional human body data. Therefore, our research makes it possible to study further advanced quantitative analysis of human body.

• 제어로봇시스템학회논문지
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• 제17권3호
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• pp.254-257
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• 2011

This study was performed to development a dental three-dimensional laser scanning system and measure the accuracy of new adjustable lower dental impression trays. Multiple impressions of a resin master model were made with custom, stock and new adjustable trays and vinyl polysiloxane impression material. The lower master model and resulting cast were compared using an dental scanning system. Each 3D image was superimposed onto the lower master model image and analyzed with custom software. Multiple measurements of the lower master model and casts were analyzed to determine the accuracy of tray types.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.47-50
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• 2008

We propose a new method evaluating the image quality of display devices using the CIECAM02 that is the recently developed CIE color appearance model and provides an extension of the previously recommended CIE color spaces. We develop the evaluation method that quantifies the color reproduction capability, emotional gray scale (gradation), and visual perception contrast (perceptual contrast range) based on the gamut in this model.

• 디지털콘텐츠학회 논문지
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• 제10권4호
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• pp.569-578
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• 2009

본 논문에서는 컬러 보정차트를 이용한 디지털 영상의 컬러 보정 알고리즘을 제안한다. 제안된 알고리즘은 기준 컬러 값과 영상으로부터 취득된 컬러 값 사이의 컬러 변환 관계를 계산하기 위하여 별도의 컬러 보정 차트를 이용한다. 기존의 컬러 재현 알고리즘은 취득된 영상에 대한 컬러 스펙트럼 분석 및 디지털 영상의 형성 과정에 대한 모델링 등을 통한 방법을 이용하여 취득된 영상에 대한 컬러를 보정하는 방법을 주로 이용한다. 제안된 알고리즘은 차트로부터 제공되는 기준 영상과 취득된 영상의 컬러 사이의 변환 관계를 이용하여 컬러 보정 과정을 수행한다. 제안된 알고리즘은 두 단계로 수행된다. 컬러 보정의 첫 번째 단계에서는 컬러 차트의 영상을 취득한 다음, 내부의 기준 컬러 값과 차트 영상으로부터 취득된 컬러 값 사이의 변환 관계를 계산한다. 두 번째 단계에서는 계산된 변환 관계를 이용하여 차트 영상과 유사한 조건에서 촬영된 영상에 대한 컬러 보정을 수행한다. 제안된 알고리즘의 성능을 평가하기 위해서 다양한 조건 하에서 실험을 수행하였으며, 이를 일반적인 상용프로그램들의 컬러 보정 성능과 비교 및 평가하였다.

• 한국콘텐츠학회논문지
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• 제8권8호
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• pp.111-118
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• 2008

현대 사회는 TV, 잡지, 신문, 인터넷 등 다양한 매체를 통해 이미지를 접할 수 있으며, 이렇게 접하는 이미지들은 의식적으로 또는 무의식적으로 사람들의 삶과 인식에 결정적인 영향을 미친다. 과거의 이미지 생산 매체들은 장면을 물리적으로 동일하게 재현하는데 주된 목적이 있었던 반면, 최근에는 인지적 선호도에 의한 재현이 중요하게 인정받고 있으며, 사진의 선호도는 TV, 잡지, 신문, 인터넷 등 주변에서 접하는 시각적 콘텐츠의 영향을 받는다. 최근 이미지를 생산하는 재현 매체로서 가장 중요하게 사용되고 있는 장비를 디지털 카메라이다. 디지털 카메라의 이미지를 형성하는 핵심은 ‘빛’인데, 빛의 양, 즉 노출의 조절을 통해 이미지를 형성하게 된다. 현재 디지털 카메라는 물리적으로 정확한 재현을 목표로 노출을 조절하도록 설정되어 있는데, 물리적으로 정확한 조절이 반드시 인지적으로 선호도가 높은 조절은 아니다. 따라서 물리적으로 정확한 노출 설정이 아니라 인지적으로 정확한 노출 설정을 찾기 위한 실험을 진행하였다. 특히 인지적으로 색상과 농도 변화에 가장 예민한 피부톤을 기준으로 실험을 진행하였으며, 성별에 따라 노출 선호도가 다를 수 있으므로 남성과 여성 모델을 각각 촬영하여 자극에 사용하였다.