• 방송공학회논문지
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• 제23권6호
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• pp.866-875
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• 2018

최근 VR 콘텐츠의 인기와 함께 다양한 촬영장치를 이용한 실사기반 VR 360 영상제작이 주목을 받고 있다. 과거 VR 콘텐츠 제작은 많은 작업이 필요해 연구소 수준에서만 가능했으나 최근 카메라의 소형화로 VR 실사 촬영이 콘텐츠 제작자들에게 보편화되고 있다. 본 논문은 오늘날 상황에서 유통되는 다양한 VR 콘텐츠를 비교 연구하고 비용면에서 강인한 실사 기반 360 영상제작의 장단점을 분석하고 있다. 기존 영상 촬영 전문가가 사용하기 어려운 단점을 지적하고 이를 위한 해결 방안을 제시하고자 한다. 액션캠이나 일체형 카메라보다 수동조작이 가능하고, 원규격(raw foramt) 지원 카메라에서 360 촬영이 영화식 후반작업에 더 적합하다는 것을 간단한 실험 촬영을 통해 증명하였다.

• 대한디지털의료영상학회논문지
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• 제9권2호
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• pp.39-43
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• 2007

In angiography, the global standard agreements of DICOM is lossless. But it brings on overload and takes too much store space in DICOM sever. Because of all those things we transmit images which is classified in subjective way. But this cause data loss and would be lead doctors to make wrong reading. As a result of that we try to transmit continued image (raw data) to reduce those mistakes. We got angiography images from the equipment(Allura FD20-Philips). And compressed it in two different methods(lossless & lossy fair). and then transmitted them to PACS system. We compared the quality of QC phantom images that are compressed by different compress method and compared spatial resolution of each images after CD copy. Then compared each Image's data volume(lossless & lossy fair). We measured spatial resolution of each image. All of them had indicated 401p/mm. We measured spatial resolution of each image after CD copy. We got also same conclusion (401p/mm). The volume of continued image (raw data) was 127.8MB(360.5 sheets on average) compressed in lossless and 29.5MB(360.5 sheets) compressed in lossy fair. In case of classified image, it was 47.35MB(133.7 sheets) in lossless and 4.5MB(133.7 sheets) in lossy fair. In case of angiography the diagnosis is based on continued image(raw data). But we transmit classified image. Because transmitting continued image causes some problems in PACS system especially transmission and store field. We transmit classified image compressed in lossless But it is subjective and would be different depend on radiologist. therefore it would make doctors do wrong reading when patients transfer another hospital. So we suggest that transmit continued image(raw data) compressed in lossy fair. It reduces about 60% of data volume compared with classified image. And the image quality is same after CD copy.

• 한국분무공학회지
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• 제26권3호
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• pp.142-148
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• 2021

The objective of this study is to analyze the basic flame behavior characteristics using the single fuel droplet combustion of diesel, palm-based biodiesel, and canola-based biodiesel. The results were compared and analyzed through the post processed image, which was applied the threshold level for removing noise in the raw image. The raw image was taken by a high-speed camera during the entire combustion process. At the same time, the maximum flame length, which was measured by the application code of the MATLAB program, the ignition delay, and the combustion period were compared and analyzed.

• Elastomers and Composites
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• 제54권2호
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• pp.110-117
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• 2019

The characterization of the ozone oxidation for raw natural rubber (NR) was investigated under controlled conditions through image and fourier transform infrared (FT-IR) analysis. The ozone oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at $40^{\circ}C$ under low humidity conditions to completely exclude thermal, moisture, or light oxidation. The ozone concentration was set at 40 parts per hundred million (pphm). Before or after exposure to ozone, the image of the thin film for raw NR was observed at a right or tilted angle. FT-IR absorption spectra were measured in the transmission mode according to ozone exposure time. The ozone oxidation of NR was determined by the changes in the absorption peaks at 1736, 1715, 1697, and $833cm^{-1}$, which were assigned to an aldehyde group (-CHO), a ketone group (-COR), an inter-hydrogen bond between carbonyl group (-C=O) from an aldehyde or a ketone and an amide group (-CONH-) of protein, and a cis-methine group ($is-CCH_3=CH-$, respectively. During ozone exposure period, the results indicated that the formation of the carbonyl group of aldehyde or ketone was directly related to the decrement of the double bond of cis-1,4-polyisoprene. Only carbonyl compounds such as aldehydes or ketones seemed to be formed through chain scission by ozone. Long thin cracks with one orientation at regular intervals, which resulted in consecutive chain scission, were observed by image analysis. Therefore, one possible two-step mechanism for the formation of aldehyde and ketone was suggested.

• International Journal of Automotive Technology
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• 제6권1호
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• pp.53-63
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• 2005

We propose a fuzzy neural network (FNN) theory capable of deciding the quality of a road image prior to extracting lane-related information. The accuracy of lane-related information obtained by image processing depends on the quality of the raw images, which can be classified as good or bad according to how visible the lane marks on the images are. Enhancing the accuracy of the information by an image-processing algorithm is limited due to noise corruption which makes image processing difficult. The FNN, on the other hand, decides whether road images are good or bad with respect to the degree of noise corruption. A cumulative distribution function (CDF), a function of edge histogram, is utilized to extract input parameters from the FNN according to the fact that the shape of the CDF is deeply correlated to the road image quality. A suitability analysis shows that this deep correlation exists between the parameters and the image quality. The input pattern vector of the FNN consists of nine parameters in which eight parameters are from the CDF and one is from the intensity distribution of raw images. Experimental results showed that the proposed FNN system was quite successful. We carried out simulations with real images taken in various lighting and weather conditions, and obtained successful decision-making about $99\%$ of the time.

• 만화애니메이션 연구
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• 통권33호
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• pp.425-447
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• 2013

디지털 카메라의 대중화로 인하여 ISP(Image Signal Process)에 관한 연구들이 활발히 일어나고 있으며 이와 함께 사용자들이 쉽게 사용할 수 있는 이미지 보정 어플리케이션들도 많이 개발되고 있다. 특히 AWB(Automatic White Balance) 와 Auto Exposure 는 ISP 기능 중에서도 가장 관심을 받는 분야로서 이미지나 영상의 질을 높이는데 많은 기여를 하고 있다. 3D 프로그램에서 라이팅과 카메라의 원리는 실제 카메라와 라이팅의 원리를 적용하여 만들어졌으나, 실제의 카메라에서 사용되고 있는 자동노출 기능과 AWB 기능들과 같은 전문적인 기능들은 3D 프로그램 상에서 구현되지 못하고 있다. 영상에서 색상의 보정은 색상에 대한 전문적인 지식이 있어야 가능하며, 합성프로그램에서 제공하는 기능들은 일반적인 디지털 사진을 보정하는 프로그램 방식에 비하여 복잡한 것이 사실이다. 특히 애니메이션을 공부하는 대학생들의 경우에는 애니메이션의 제작과정에 있어서 색상보정의 과정을 생략하고 렌더링과 합성과정을 거쳐서 애니메이션을 완성하고 있다. 따라서 본 연구는 색상보정에 사용하는 기능들을 3D 애니메이션제작 실사에서 적용 가능하게 함으로서 색상에 대한 전문적인 지식이 없는 사람이라도 쉽게 색상을 보정하여 렌더 이미지의 퀼리티를 높이는 3D 제작 파이프라인을 본 연구를 통하여 제시하고자 한다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 춘계학술발표논문집
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• pp.738-741
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• 2009

본 논문에서는 RAW 이미지 포맷 중 PEF, MRW에 대한 분석 결과와 RAWImage Viewer에 대해 소개한다. DSLR 디지털 카메라로 촬영되는 이미지 파일은 범용의 JPEG 포맷이나 제조사별 독자적인 RAW 이미지 포맷으로 저장된다. 이러한 RAW 이미지 파일을 PMP 등의 휴대용 멀티미디어 기기나 디지털액자에서 재생 및 확인하기 위한 요구가 증대되고 있다. 하지만, RAW 이미지 포맷이 디지털 카메라 제조사별로 다르고, 해당 포맷에 대한 구체적인 정보가 공개되지 않아 대부분의 휴대용 멀티미디어 기기에서 RAW 이미지 파일 재생 기능을 완벽하게 지원하지 못하고 있다. 본 논문에서는 RAW 이미지 파일 포맷을 분석하여 다양한 임베디드 멀티미디어 기기에서 모든 RAW 이미지 파일을 지원할 수 있는 라이브러리 구축을 위한 연구 결과 중 일부를 소개한다. Cannon의 CRW, CR2 포맷과 Nikon의 NEF 분석 결과에 이어 PEF, MRW에 대한 분석 결과와 RAW 이미지 출력 및 분석 기능이 포함된 RAWImage Viewer에 대해 설명한다. 연구 결과는 RAW 파일을 재생할 수 있는 임베디드 장비 및 PC용 RAW 이미지 파일 재생 라이브러리를 구축 및 응용 프로그램 개발시 활용될 것이다.

• 한국컴퓨터산업학회논문지
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• 제3권9호
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• pp.1177-1188
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• 2002

본 논문에서는 생산현장에서 생산하는 Lead Pin을 생산근로자의 시각으로 품질을 검사하는 방법을 개선하기 위하여, 영상처리 알고리즘을 사용하여 자동으로 품질의 정ㆍ오판별을 검사하기 위한 실시간 영상처리방법을 제안한다. 먼저 영상정보의 실시간 취득을 위하여 C.C.D와 영상취득기(Image frame grabber : DT3153)를 사용하여 초당 30프레임(30 Frame/second)으로 영상을 취득할 수 있는 실시간 영상취득시스템을 구성하였으며, 이를 사용하여 Lead Pin의 영상을 취득하여 Lead pin의 형상을 나타내는 형상프로파일의 영상처리 알고리즘을 사용하여 연구를 수행하였다. Lead Pin의 정품과 비정품을 평가하기 위해 숙련된 작업자에 의해 판별된 정품 100개, 비정품 100개, 전체 200개의 인식대상 물체를 판별한 수행결과 정품을 정품으로 인식하여 판별한 경우는 97%, 비정품을 비정품으로 판별한 경우는 95%로 전체 인식률은 96%의 인식결과를 나타내었으며, 전체 오분류률은 4%를 나타냄을 알 수 있었다.

• Current Optics and Photonics
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• 제5권5호
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• pp.524-531
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• 2021

In an integral-imaging microscopy (IIM) system, a microlens array (MLA) is the primary optical element; however, surface errors impede the resolution of a raw image's details. Calibration is a major concern with regard to incorrect projection of the light rays. A ray-tracing-based calibration method for an IIM camera is proposed, to address four errors: MLA decentering, rotational, translational, and subimage-scaling errors. All of these parameters are evaluated using the reference image obtained from the ray-traced white image. The areas and center points of the microlens are estimated using an "8-connected" and a "center-of-gravity" method respectively. The proposed approach significantly improves the rectified-image quality and nonlinear image brightness for an IIM system. Numerical and optical experiments on multiple real objects demonstrate the robustness and effectiveness of our proposed method, which achieves on average a 35% improvement in brightness for an IIM raw image.

• Elastomers and Composites
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• 제55권1호
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• pp.51-58
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• 2020

In this study, the thermal oxidation of raw natural rubber (NR) was investigated under controlled conditions by optical image and fourier transform infrared (FT-IR) analysis. The thermal oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at 80℃ under low humidity conditions to completely exclude moisture and restrict light oxidation. Images of the thin film of raw NR were obtained before and after thermal oxidation. FT-IR absorption spectra were measured in the transmission mode at different thermal exposure times. The thermal oxidation of NR was examined by the changes in the absorption peaks at 3449, 1736, 1447, 1377, 1242, 1072, and 833 cm^-1, which corresponded to a hydroxyl group (-OH), a carbonyl group (-C=O) from an aldehyde and a ketone, a methylene group (-CH₂-), a methyl group (-CH₃), a carbon-oxygen single bond (-C-O) from an epoxide, a carbon-oxygen bond (-C-O) from an ether, an alcohol, a peroxide, or a cyclic peroxide, and a cis-methine group (cis-CCH₃=CH-), respectively. In the initial stage of thermal oxidation, two different types of free radicals were produced quickly and randomly by the homolytic cleavage of a double bond and allylic hydrogen abstraction. Aldehydes and ketones were formed from chain scissions of the double bonds and alcohols were produced from allylic hydrogen abstraction at the methylene or methyl groups. Two reactions seemed to proceed competitively with each other. At a later stage, oxidative crosslinks seemed to dominate through the combination of free radicals such as an allyl radical (CH=CHCH₂·), alkoxy radical (RO·), and peroxy radical (ROO·) and the reaction of a hydroperoxide (-ROOH) with a double bond. The image obtained after thermal oxidation showed hardening without cracks. Based on these observations, a plausible two-step mechanism was suggested for chain hardening caused by the thermal oxidation.