• 제목/요약/키워드: Image Transformation

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조명과 해상도에 강인한 자동 결함 검사를 위한 향상된 히스토그램 정합 방법 (An Enhanced Histogram Matching Method for Automatic Visual Defect Inspection robust to Illumination and Resolution)

  • 강수민;박세혁;허경무
    • 제어로봇시스템학회논문지
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    • 제20권10호
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    • pp.1030-1035
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    • 2014
  • Machine vision inspection systems have replaced human inspectors in defect inspection fields for several decades. However, the inspection results of machine vision are often affected by small changes of illumination. When small changes of illumination appear in image histograms, the influence of illumination can be decreased by transformation of the histogram. In this paper, we propose an enhanced histogram matching algorithm which corrects distorted histograms by variations of illumination. We use the resolution resizing method for an optimal matching of input and reference histograms and reduction of quantization errors from the digitizing process. The proposed algorithm aims not only for improvement of the accuracy of defect detection, but also robustness against variations of illumination in machine vision inspection. The experimental results show that the proposed method maintains uniform inspection error rates under dramatic illumination changes whereas the conventional inspection method reveals inconsistent inspection results in the same illumination conditions.

Sensors Comparison for Observation of floating structure's movement

  • Trieu, Hang Thi;Han, Dong Yeob
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2014년도 추계학술대회
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    • pp.219-221
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    • 2014
  • The objective of this paper is to simulate the dynamic behavior of a floating structure model, using image processing and close-range photogrammetry, instead of the contact sensors. Previously, the movement of structure was presented through the exterior orientation estimation of a single camera by space resection. The inverse resection yields the 6 orientation parameters of the floating structure, with respect to the camera coordinate system. The single camera solution is of interest in applications characterized by restriction in term of costs, unfavorable observation conditions, or synchronization demands when using multiple cameras. This article discusses the theoretical determinations of camera exterior orientation based on Direct Linear Transformation and photogrammetric resection using least squares adjustment. The proposed method was used to monitor the motion of a floating model. The results of six degrees of freedom (6-DOF) by inverse resection show that the appropriate initial values by DLT can be effectually applied in least squares adjustment, to obtain the precision of exterior orientation parameters. Additionally, a comparison between the close-range photogrammetry and total station results was feasibly verified. Therefore, the proposed method can be considered as an efficient solution to simulating the movement of floating structure.

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CEGI를 이용한 3D 메쉬 워터마킹 (3D Mesh Watermarking Using CEGI)

  • 이석환;김태수;김승진;권기룡;이건일
    • 한국통신학회논문지
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    • 제29권4C호
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    • pp.472-484
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    • 2004
  • 본 논문에서는 CEGI (Complex Extended Gaussian Image)를 이용한 3D 메쉬 모델 워터마킹 알고리즘을 제안하였다. 제안한 알고리즘에서는 VRML 데이터의 3D 메쉬 모델을 6개 패치로 분할한 후, 각 패치의 CEGI 분포에서 복소 가중치의 크기가 큰 셀에 투영되는 메쉬의 법선 백터 방향에 워터마크를 삽입한다. 그리고 각 패치의 중점 좌표 및 CEGI 크기 분포의 우선 순위 정보를 이용하여 워터마크를 추출한다. 또한 아편 (affine) 변형된 모델에서는 패치의 초기 중점 좌표의 재배열 과정을 이용하여 원 모델의 방향으로 전환한 후, 워터마크를 추출한다. 본 논문에서 제안한 알고리즘의 성능을 평가하기 위한 실험에서 기하학적 및 위상학적 변형에 강인한 특성을 가짐을 확인하였다.

효율적인 DICOM 데이터 전송을 위한 모바일 PACS 설계 (Design of Mobile PACS for Effective DICOM Data Transmission)

  • 김귀정
    • 디지털융복합연구
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    • 제12권10호
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    • pp.329-335
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    • 2014
  • 핸드폰과 무선망의 보급이 보편화되면서 사용자가 이동 중 또는 병원이 아닌 외부에서 무선통신망을 이용하여 의료영상을 조회하고자 하는 요구가 급속히 늘어나고 있다. 이에 본 논문은 모바일 PACS 플랫폼을 개발하여 스마트폰을 사용하는 의사와 환자가 원하는 의료영상을 저장 검색 조회 전송할 수 있는 시스템을 설계하고자 한다. 제안한 시스템은 병원의 PACS 서버로부터 환자의 DICOM 영상을 조회하고, 이를 스마트폰 표준에 맞도록 변환한 후, 영상을 전송할 수 있는 모바일 기반 PACS 플랫폼이다. 이를 위해 PACS와 mPACS 그리고 사용자 간에 이루어지는 데이터 전송에 대한 플랫폼을 설계하였고, PACS 서버에 존재하는 DICOM 영상을 스마트폰에서 디스플레이하기 위한 DICOM 변환과정을 제안하였다.

현대패션에 나타난 아트모드에 관한 연구 (A Study of the Art Mode in Modern Fashion)

  • 김선영
    • 복식
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    • 제59권8호
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    • pp.1-14
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    • 2009
  • This study was aimed to make clear fashion is an expression art displaying not only functional or commercial aspects, but creative functions as an artistic work by analyzing Art Mode and its values, and to help develop more creative design by combining fashion with art. In terms of method, relevant documents, precedent studies, and the works announced in domestic and foreign fashion collections, such as Vogue, Fashion News, Gap, and Collections from 2000 to 2009. According to the findings, artistic works were used by the Art Mode in modern fashion. The respect of artists was expressed using historic famous painting works or current works in various fields, designers' individuality was shown by directly applying work messages to clothes, and fashion design was converted into a tool to communicate the messages like artistic works. Second, the various styles, using the formative character of modern art styles from animalism to modern abstractism, showed the creativity of design, transformed art into the art that enables to see the image of modern art, and presented the possibility of developing into a newer creative design through the application of numerous art styles and the transformation of ideas. Third, the collaboration with artists was used. Fashion designers or fashion brands tried to change the images of works or brands in partnership with artists or to increase differentiated images. The future direction of fashion is a pursuit of new form and content to express fashion, not simply to use artistic works. It is expected that such pursuit will lead to more creative and artistic fashion design.

옵아트와 전통 떡살의 기하문양을 조합한 스카프디자인 연구 (Scarf Design Combined with Opt Art and Geometrical Pattern of Traditional Ddeoksal)

  • 김선영
    • 한국의류산업학회지
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    • 제15권3호
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    • pp.325-335
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    • 2013
  • This work develops a motif design integrated with geometrical patterns in traditional ddeoksal and that can be applied to a scarf design so that traditional elements unique to Korean culture can be developed further for a modern application to various design fields. For the research method, literature reviews on op art and traditional ddeoksal were conducted with Adobe Illustrator CS3 and Adobe Photoshop CS3. As for the motif combination, such applications were taken as five pieces from the works of Victor Vasarely and some traditional ddeoksal shapes such as oblique line pattern, taegeuk pattern, and geometrical pattern. Abstract and geometrical images were borrowed from op art and ddeoksal for image expression. The total number of works selected was eleven. To realize the applied scarf design, a motif layout was performed with the scarf center or rim highlighted so that each design feature could be remarkable based on the motif combination. With the function of scaling, rotation, opacity control, filtering effect, the changed images were shown through motif distortion. In addition, this work applies a single combined motif to products for a possible transformation into handkerchiefs and boutique scarfs in the case of smaller sized scarfs.

Hypointensity on Susceptibility-Weighted Images Prior to Signal Change on Diffusion-Weighted Images in a Hyperacute Ischemic Infarction: a Case Study

  • Kim, Dajung;Lee, Hyeonbin;Jung, Jin-Man;Lee, Young Hen;Seo, Hyung Suk
    • Investigative Magnetic Resonance Imaging
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    • 제22권2호
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    • pp.131-134
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    • 2018
  • Susceptibility-weighted imaging (SWI) is well known for detecting the presence of hemorrhagic transformation, microbleeds and the susceptibility of vessel signs in acute ischemic stroke. But in some cases, it can provide the tissue perfusion state as well. We describe a case of a patient with hyperacute ischemic infarction that had a slightly hypodense, patchy lesion at the left thalamus on the initial SWI, with a left proximal posterior cerebral artery occlusion on a magnetic resonance (MR) angiography and delayed time-to-peak on an MR perfusion performed two hours after symptom onset. No obvious abnormal signals at any intensity were found on the initial diffusion-weighted imaging (DWI). On a follow-up MR image (MRI), an acute ischemic infarction was seen on DWI, which is the same location as the lesion on SWI. The hypointensity on the initial SWI reflects the susceptibility artifact caused by an increased deoxyhemoglobin in the affected tissue and vessels, which reflects the hypoperfusion state due to decreasing arterial flow. It precedes the signal change on DWI that reflects a cytotoxic edema. This case highlights that, in some hyperacute stages of ischemic stroke, hypointensity on an SWI may be a finding before the hyperintensity is seen on a DWI.

공개키 공격에 안전한 비대칭 워터마킹 (A Secure Asymmetric Watermarking to the Public Key Attack)

  • 이덕;김종원;최종욱
    • 한국컴퓨터정보학회논문지
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    • 제13권7호
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    • pp.173-180
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    • 2008
  • 본 논문에서는 공개키 공격에 안전한 비대칭 워터마킹 시스템을 구성하기 위하여 효과적인 공개 키 및 개인 키 생성 알고리즘을 제안한다. 공개 키와 개인 키의 생성은 특수행렬을 이용한 선형변환 방식에 기초하였으며 높은 상관도 검출이 가능하도록 구성되었다 또 공개 키 공격에 대한검증과 검출을 위한 공개 키를 추가로 생성하여 분배하는 방안을 제안하여 특정된 환경에서 공개 키 공격에 효과적으로 대응하도록 하였다. 실험결과 워터마크가 삼입된 영상에서 공개 키 및 개인 키를 이용하여 효과적으로 높은 상관도 검출을 할 수 있었으며 공개 키 공격을 받은 영상에서 추가로 발급된 검증용 공개 키를 이용하여 효과적으로 상관도 검출을 할 수 있음을 확인하였다.

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Multi-view 영상 코딩에서 영상 개선 알고리듬 (An algorithm for the image improvement in the multi-view images coding)

  • 김도현;최동준;양영일
    • 전자공학회논문지S
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    • 제35S권7호
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    • pp.53-61
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    • 1998
  • In this paper, we propose an efficient multi-view images coding algorithm to find the optimal depth and texture from the set of multi-view images. The proposed algorithm consists of two consecutive steps, i) the depth estraction step, and ii) the texture extraction step, comparedwith the traditional algorithem which finds the depth and texture concurrently. The X-Y plane of the normalized object space is divided into traingular paatches and the Z value of the node is determined in the first step and then the texture of the each patch is extracted in the second step. In the depth extraction step, the depth of the node is determined by applying the block based disparity compensation method to the windowed area centered at the node. In the second step, the texture of the traingular patches is extracted from the multi-view images by applying the affine transformation based disparity compensation method to the traingular pateches with the depth extracted from the first step. Experimental results show that the SNR(Singnal-to- Noise Ratio) of images enconded by our algorithm is better than that of images encoded by the traditional algorithm by the amount about 4dB for for the test sets of multi-view images called dragon, kid, city and santa.

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고차 다층구조 신경회로망을 이용한 LCD 모니터의 색 보정 (Color Collection of LCD Monitor Using High-order Multilayer Neural Network)

  • 정재훈;이동욱;안강식;조석제
    • 정보처리학회논문지B
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    • 제11B권2호
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    • pp.169-176
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    • 2004
  • 본 논문에서는 고차 다층구조 신경회로망을 이용한 LCD 모니터의 색 보정 방법에 관하여 제안하였다. LCD 모니터는 다양한 디스플레이 시스템 구성요소로 인해 비선형적인 특성을 지닌다. 이러한 비선형적 특성들을 해결하고 양질의 영상을 나타내기 위해서는 LCD 모니터좌표와 입력되는 색 자극치 사이의 비선형 색 좌표변환이 필요하다. 고차 다층구조 신경회로망은 학습을 통해 입력되는 색 자극치를 효과적으로 모니터에 가상한다. 실험을 통해 제안한 방법이 칼라 영상의 재현에 효과적임을 확인하였다.