• 제목/요약/키워드: occluding pattern

검색결과 6건 처리시간 0.02초

다중 파노라마 영상기반 네비게이션에서 연속적인 시점이동을 위한 장면보간 방법 (View Interpolation Algorithm for Continuously Changing Viewpoints in the Multi-panorama Based Navigatio)

  • 김대현;최종수
    • 대한전자공학회논문지SP
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    • 제40권6호
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    • pp.141-148
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    • 2003
  • 본 논문은 다수의 파노라마 영상을 이용하여 가상환경을 탐색하는 시스템에서 사용자가 한 시점에서 다른 시점으로 자연스럽게 시점을 이동할 수 있도록 중간 장면을 합성하는 알고리즘을 제안한다. 제안된 방법은 두 파노라마 영상에서 시선방향을 일치시키는 사전 교정(prewarping) 단계와 시선방향이 일치된 두 영상에서 대응점을 찾아 중간 시점의 영상을 생성하는 양방향 시차 몰핑(bidirectional disparity morphing) 단계로 나누어진다. 사전 교정은 푸리에(Fourier) 성질을 이용해서 두 영상간의 위상 상관 관계(phase correlation)를 분석한 후, 두 영상 사이의 상대적인 변리, 회전 그리고 축적 변화를 계산하여 시선방향을 일치시킨다. 그리고 양방향 시파 몰핑에서는 블록 단위의 시차 벡터(disparity vector)를 계산하고, 가려짐 영역에 대한 정착한 시차를 추정하기 위해 가려짐 패턴(occluding pattern)을 이용하였다. 제안된 방법은 실제 파노라마 영상에 적용하여 실험하였고, 그 결과 두 파노라마 영상 사이를 자연스럽게 이동할 수 있었다.

Volumetric 집적영상에서 분산 추정을 이용한 심하게 은폐된 물체의 향상된 복원 (Enhanced Reconstruction of Heavy Occluded Objects Using Estimation of Variance in Volumetric Integral Imaging (VII))

  • 황용석;김은수
    • 한국광학회지
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    • 제19권6호
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    • pp.389-393
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    • 2008
  • 본 논문에서는 컴퓨터 집적영상(integral imaging(II))에서 분산 추정을 이용하여 심하게 은폐된 물체의 복원 시 은폐물(occluding object)의 블러링 효과를 제거하는 방법을 제안하였다. 하나의 요소영상(elemental image) 군으로부터 은폐 효과를 제거하여 복원된 영상의 선명도를 향상시키는 정보를 추출하는 방법을 분석하였다. 이를 실행하기 위해 픽업되는 요소영상들이 높은 해상도, 낮은 초점오차(focus error), 큰 깊이감을 가질 필요가 있다. 요소 영상을 픽업할 때 디지털 컴퓨터를 이용한 synthetic aperture integral imaging(SAII)이 채택되었다. 컴퓨터(Computational) II에서는 복원 면의 위치에 따라 복원되는 영상의 촛첨이 맺히는 영역이 달라진다. 심하게 은폐된 물체 영상의 복원은 은폐 물체의 블러링(bluring) 효과가 복원 면에 전체적으로 크게 나타나기 때문에 선명한 복원을 할 수가 없다. 이러한 은폐물의 블러링 효과가 제거된 복원 영상을 얻기 위해 분산 추정이라는 통계적인 방법이 채택되었다.

Computational Integral Imaging Reconstruction of a Partially Occluded Three-Dimensional Object Using an Image Inpainting Technique

  • Lee, Byung-Gook;Ko, Bumseok;Lee, Sukho;Shin, Donghak
    • Journal of the Optical Society of Korea
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    • 제19권3호
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    • pp.248-254
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    • 2015
  • In this paper we propose an improved version of the computational integral imaging reconstruction (CIIR) for visualizing a partially occluded object by utilizing an image inpainting technique. In the proposed method the elemental images for a partially occluded three-dimensional (3D) object are recorded through the integral imaging pickup process. Next, the depth of occlusion within the elemental images is estimated using two different CIIR methods, and the weight mask pattern for occlusion is generated. After that, we apply our image inpainting technique to the recorded elemental images to fill in the occluding area with reliable data, using information from neighboring pixels. Finally, the inpainted elemental images for the occluded region are reconstructed using the CIIR process. To verify the validity of the proposed system, we carry out preliminary experiments in which faces are the objects. The experimental results reveal that the proposed system can dramatically improve the quality of a reconstructed CIIR image.

상공정맥-우폐동맥 문합에 관한 실험적 연구 (Experimental Study on Cavo-Pulmonary Anastomosis)

  • 양기민
    • Journal of Chest Surgery
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    • 제10권2호
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    • pp.281-294
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    • 1977
  • Superior vena cava to pulmonary arterial shunting operation was made between the superior vena cava and the right pulmonary artery in the fashion of end-to-end anastomosis in 20 mongrel dogs. The experimental animals were divided into three group and blood flow in the superior vena cava was occluded for 20, 30 and 60 minutes respectively, and observations were made for the changes in caval pressure and cerebrospinal fluid pressure. And pathologic examinations were also performed. On occluding the caval blood flow, the superior vena caval pressure was sharply and immediately elevated from $103.5{\pm}19.8mmH_2O$ at thoracotomy to $556.4{\pm}86.lmmH_2O$ within 2 minutes to make its plateau thereafter, and the cerebrospinal fluid pressure followed closely the changes of the superior vena caval pressure in its level and pattern being elevated from $102.0{\pm}19.9mmH_2O$ to $490.5{\pm}79.9mmH_2O$. The drops of both the caval and cerebrospinal fluid pressures were definite and marked on opening the shunt flow through the anastomosis, but these postoperative pressures retained still higher ones above their levels measured at thoracotomy. The pathological examinations of the brain and the spinal cord were also performed in six animals. Characteristic changes uniformly seen in all area and in all animals were the findings of capillary congestion and perivascular edema. On the other hand, ischemic nerve cell changes were rather evident, revealing their degrees and extents being related to the prolongation of the time of caval occlusion which has followed by the sustained high pressures in both the superior vena and the cerebrospinal fluid. The experiment suggests the safety of this surgical procedure with minimal, if any, permanent damage as long as the occlusion of the caval blood flow is not prolonged beyond the expected.

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양방향 시차 몰핑을 이용한 중간 시점 영상 보간 (Intermediate Scene Interpolation using Bidirectional Disparity)

  • 김대현;윤용인;최종수;김제우;최병호
    • 대한전자공학회논문지SP
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    • 제39권2호
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    • pp.107-115
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    • 2002
  • 본 논문은 한 쌍의 스테레오 영상으로부터 BDM(Bidirectional Disparity Morphing)을 이용하여 중간시점 영상을 보간하는 방법을 제안한다. 영상은 하나 이상의 계층으로 구성되어 있고 각각의 계층은 유사한 시차값을 갖기 때문에, 블록 단위의 시차 맵을 이용하는 것은 유용하다. 또한 블록 단위의 시차 맵은 시차계산을 위한 영상의 해상도를 줄여 계산량을 크게 감소시킨다. 그러나 서로 다른 계층이 겹쳐진 영역에서는 시차가 급격히 변화하여 정합 오차가 증가하고, 가려짐이 발생할 확률이 높다. 따라서 정합 결과에 따라 블록의 크기를 변화시켜 보다 정밀하게 대응 블록을 검색하여 잘못된 시차 계산을 막고, 아울러 가려진 영역을 검출할 수 있다. 가려진 영역의 시차는 가려짐 패턴을 이용하여 올바른 시차를 지정할 수 있어, 결과적으로 보다 정확한 중간 시점 영상을 생성할 수 있다.

Superimposed Rubber Pattern법에 의한 성인 정상 및 비정상 교합자의 교합 양상에 관한 연구 (A STUDY OF THE NORMAL & ABNORMAL OCCULSAL PATERNS IN ADULTS USING THE SUPERIMPOSED RUBBER PATTERN METHOD)

  • 최대균;이성복;권영혁;최부병
    • 대한치과보철학회지
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    • 제33권3호
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    • pp.467-491
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    • 1995
  • In order to analyze the occlusin of intercuspation with maximun bite force, fifteen healthy adult subjects with the ages 23 to 27 were studied(Group1 ; 5-normal occlusion with Angle's Class1, Group2 ; 5-Angle's Class2 malocclusion, Group3 ; 5-Angle’s Class3 malocclusion). Head Position was fixed with occlusal plane paralleling to horizontal line and occlusal registration r cord was made with polyether rubber impression material(Ramitec, ESPECo. West Germany). After all subject were trained for maximum intercuspation at least 5 times, occlusal registration procedure was repeated for this study. Lower posterior rubber occlusal registration records were sliced with 1mm thickness using precision metal sliding channel(Hitachi Ind. Co., Japan). Gross sectional drawings were traced from occluding view of upper and lower posterior teeth on the rubber slices using digitizer, and superimposed for the determination of each drawing distance(Superimposed Rubber Pattern Method). Based on superimposed rubber pattern drawings, total area of occlusal view, sum of each area of the 5 divided occlusal contact provinces and its ratio, total area and number of occlusal contact area were determined to elucidate occlusal stability in the normal and abnormal occlusion groups. The data were analysed by t-test(p=0.05) to determine statistical significance. The obtained results were as follows : 1. Group1 showed the largest standard area with occlusal view of the lower posterior teeth and Group3 showed the smallest area. There was a significant difference between Group2 and Group3(p=0.025), and Gropu1 was not statistically different for both Group2 and Group3. 2. Means and ratio of the under 2.0mm area(D) and ratio showed $197.49mm^2$, 59.76% in Group1, $188,69mm^2$, 56.10% in Group2, and $174.23mm^2$, 55.76% in Group3. The results that Group1 has the most area/ratio and Group3 has the least area/ratio can be considered Group1 is the most advantageous for masticatory effective area, and Group3 is the least adnantageous. 3. Means and ratio of the under 1.0mm area(C) were $198.96mm^2$, 42.65% in Group1, 123.06$mm^2$, 46.58% in Group2, and $92.24mm^2$, 29.52% in Group3. These data means that Group1 is the most advantageous in terms of masticatory effective area and Group3 is the least. 4. Means and ratio of the under 0.5mm area(B) were $86.68mm^2$, 26.68% in Group1, $62.98mm^2$, 18.71% in Group2, and $36.44mm^2$, 11.66% in Group3. These can also be considered Group1 is the most advantageous for masticatory effective area and occlusal stability. 5. Means and ratio of the under 0.05mm area(A) were $30.92mm^2$, 9.21% in Group1, $14.31mm^2$, 4.25% in Group2, and $7.59mm^2$, 2.43% in Group3. The area ratio of the each subject group was(4.1) : (1.9) : (1)and the data of the under 0.05mm area has the intimate relationship with inter-group and intra-group data/ratio. 6. First molar showed the most occlusal contact points in all subject group and Group1 showed somewhat uniformly distributed occlusal contact point except first premolar. In Group2, all contact point in posterior teeth showed significantly reduced distribution except first molar. Group3 showed evenly distributed contace points in first and second molars.

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