• 제목/요약/키워드: Back Projection

검색결과 202건 처리시간 0.029초

SYNTHESIS OF STEREO-MATE THROUGH THE FUSION OF A SINGLE AERIAL PHOTO AND LIDAR DATA

  • Chang, Ho-Wook;Choi, Jae-Wan;Kim, Hye-Jin;Lee, Jae-Bin;Yu, Ki-Yun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.508-511
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    • 2006
  • Generally, stereo pair images are necessary for 3D viewing. In the absence of quality stereo-pair images, it is possible to synthesize a stereo-mate suitable for 3D viewing with a single image and a depth-map. In remote sensing, DEM is usually used as a depth-map. In this paper, LiDAR data was used instead of DEM to make a stereo pair from a single aerial photo. Each LiDAR point was assigned a brightness value from the original single image by registration of the image and LiDAR data. And then, imaginary exposure station and image plane were assumed. Finally, LiDAR points with already-assigned brightness values were back-projected to the imaginary plane for synthesis of a stereo-mate. The imaginary exposure station and image plane were determined to have only a horizontal shift from the original image's exposure station and plane. As a result, the stereo-mate synthesized in this paper fulfilled epipolar geometry and yielded easily-perceivable 3D viewing effect together with the original image. The 3D viewing effect was tested with anaglyph at the end.

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의복설계를 위한 성인여성의 유형형태의 관찰II-3차원 계측법에 의한 유형의 횡단면도 및 체표면전개도의 분석 ,일본 여자대학생을 중심으로- (Observation on Neck Form of Young Japanese Women for Clothing DesignII-Analysis of Horizontal Sectional Neck Serface & Draft of Neck Serface Using 3-D Data-)

  • 김희숙
    • 복식
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    • 제36권
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    • pp.139-148
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    • 1998
  • In order to know what sorts of features of neck form may be required to make plans for tight collars, the neck form of young japanese women were measured three demension-ally using GRASP(Grating Projection System for Profiling) and plaster torso. By the BASIC language in NEC computer and EXCEL program in MACINTOSHI computer, it became possible to draft a number of neck surface auomatically, therefore, we got analysis of a mass of subjects. Thed following results were obtained: 1. There was a large individual difference in the shape of neck, in particular, on the front and side curves of the neck base line, where the undulation of clavicular part of neck and inclination of shoulder are refracted. 2. When designing a stand collar, from the viewpoint of clothing strcture, it is important to grasp exactly the shapes of the neck, such as the line of the neck base, the neck gradient, back neck length, back neck width & girth. 3. According to the somatotypes(turing-over, standard, bending type), there were different the method of the basic collar pattern making.

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비노출 방수층에 작용하는 정하중과 동하중 작용 후의 방수층 물성변화에 관한 연구 (A Study on the Change of Physical Capability of Waterproofing Layer after the Application of Static Load and Moving Load to a Non-Exposed Type Waterproofing Layer)

  • 선윤숙;김진성;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2007년도 춘계학술논문 발표대회
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    • pp.141-145
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    • 2007
  • The part in the structure that is most affected by changes of external temperature is the protective concrete layer that protects a waterproofing layer. Also, the waterproofing layer that is situated under or on the back of such a protective concrete layer is affected by temperature and the behavior of the protective concrete layer under the condition of consolidation or close adhesion. In particular, in many cases, the damage is serious mainly around the projection (such as a parapet), crack, and joint (expansion joint). However, there is no proper way of examining again the non-exposed waterproofing layer once it has been constructed. Therefore, there is an assessment only on the physical property of materials and the capability of the layer in construction, and there is no actual assessment in consideration of its environmental condition or the condition of the use of buildings after construction. Therefore, in order to create more pleasant buildings and to enhance the durability of structures, this study conducts research into the change of capability of non-exposed waterproofing material after the application of a static load and moving load on the waterproofing layer situated under or on the back of protective concrete.

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Convolution 알고리즘을 이용한 영상 재구성필터에 관한 연구 (Critical Review of Reconstruction Filters for Convolution Algorithms)

  • 라종범
    • 대한전자공학회논문지
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    • 제17권1호
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    • pp.14-22
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    • 1980
  • 이차원 영상 재구성을 위해서는 Fouler convolution 알고리즘이 주로 사용되고 있다. 이때 사용되는 필터의 설계에는 몇가지 선택의 여지가 있다. 이 논문은 지금까지 제안된 영상 재구성 필터들을 sampling rate와 aliasing과 잡음의 견지에서 이론적으로 비교, 검토하고 이를 토대로 새로운 필터의 설계방법을 제안하였다. 또한 컴퓨터 simulation을 통해 기존의 재구성 필터와 제안된 필터의 이론적인 분석 결과를 확인, 검토하였다.

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Development of Two Dimensional Filter for the Reconstructive Image Processing

  • Lee, Hwang-Soo
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1979년도 하계 전자.전기연합학술발표회논문집
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    • pp.164-165
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    • 1979
  • Two dimensional kernels which reconstruct the tomographic image from the blurred one formed by simple back-projection are investigated and their performances are compared. These kernels are derived from tile point spread function of the tomographic system and have the form of a ramp filter modified by several window functions to suppress ringing in the reconstruction. Computer simulation using a computer generated phantom image data with different correction functions(kernels) has been carried out. In this simulation, filtering in frequency domain by 2-D FFT technique or in space domain by 2-D direct convolution is considered. It is found that the-computation time required for real space convolution technique is much larger than that of Fourier 2-D filtering technique in the pratical situation.

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3-D Inverse Radon Transform by Use of Tree-Structured Filter Bank

  • Morikawa, Yoshitaka;Murakami, Junichi
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -1
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    • pp.184-187
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    • 2002
  • Two-dimensional (2-D) X-ray computerized tomography (CT) equipments are widely used in industrial and medical fields, and nowadays studies on reconstruction algorithm for 3-D cone-beam acquisition systems are active for better utilization. The authors recent-By have proposed a fast reconstruction aigorithm using tree-structured filter bank for 2-D C1, and shown the algorithm is applicable to an approximate reconstruction of 3-D CT. For exact 3-D CT reconstruction, however, we have to backproject 1-D signal into 3-D space. This paper proposes a fast implementation method for this back-projection by use of tree-structured filter bank. and shows the proposed method works approximately 700 times faster than the direct one with almost same reconstruction image quality.

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Scattering Model for Electrical-Large Target Employing MLFMA and Radar Imaging Formation

  • Wu, Xia;Jin, Yaqiu
    • Journal of electromagnetic engineering and science
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    • 제10권3호
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    • pp.166-170
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    • 2010
  • To numerically calculate electromagnetic scattering from the electrical-large three-dimensional(3D) objects, the high-frequency approaches have been usually applied, but the accuracy and feasibility of these geometrical and physical optics(GO-PO) approaches, to some extent, are remained to be improved. In this paper, a new framework is developed for calculation of the near-field scattering field of an electrical-large 3D target by using a multilevel fast multipole algorithm(MLFMA) and generation of radar images by using a fast back-projection(FBP) algorithm. The MPI(Message Passing Interface) parallel computing is carried out to multiply the calculation efficiency greatly. Finally, a simple example of perfectly electrical conducting(PEC) patch and a canonical case of Fighting Falcon F-16 are presented.

K-means Clustering 기법과 신경망을 이용한 실시간 교통 표지판의 위치 인식 (Real-Time Traffic Sign Detection Using K-means Clustering and Neural Network)

  • 박정국;김경중
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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    • pp.491-493
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    • 2011
  • Traffic sign detection is the domain of automatic driver assistant systems. There are literatures for traffic sign detection using color information, however, color-based method contains ill-posed condition and to extract the region of interest is difficult. In our work, we propose a method for traffic sign detection using k-means clustering method, back-propagation neural network, and projection histogram features that yields the robustness for ill-posed condition. Using the color information of traffic signs enables k-means algorithm to cluster the region of interest for the detection efficiently. In each step of clustering, a cluster is verified by the neural network so that the cluster exactly represents the location of a traffic sign. Proposed method is practical, and yields robustness for the unexpected region of interest or for multiple detections.

A NOTE ON INVARIANT PSEUDOHOLOMORPHIC CURVES

  • Cho, Yong-Seung;Joe, Do-Sang
    • 대한수학회보
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    • 제38권2호
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    • pp.347-355
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    • 2001
  • Let ($X, \omega$) be a closed symplectic 4-manifold. Let a finite cyclic group G act semifreely, holomorphically on X as isometries with fixed point set $\Sigma$(may be empty) which is a 2-dimension submanifold. Then there is a smooth structure on the quotient X'=X/G such that the projection $\pi$:X$\rightarrow$X' is a Lipschitz map. Let L$\rightarrow$X be the Spin$^c$ -structure on X pulled back from a Spin$^c$-structure L'$\rightarrow$X' and b_2^$+(X')>1. If the Seiberg-Witten invariant SW(L')$\neq$0 of L' is non-zero and $L=E\bigotimesK^-1\bigotimesE$ then there is a G-invariant pseudo-holomorphic curve u:$C\rightarrowX$,/TEX> such that the image u(C) represents the fundamental class of the Poincare dual $c_1$(E). This is an equivariant version of the Taubes' Theorem.

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다중주파수 시간조화신호를 사용한 도체기둥의 초고주파 incoherent 영상 : Part II - 도체기둥의 초고주파 incohernet 영상 (Microwave Incoherent Imaging of a Conducting Cylinder by using Multi-Frequency Time-Harmonic Field : Part II - Microwave Incoherent Imaging of a Conducting Cylinder)

  • 강진섭;라정웅
    • 전자공학회논문지B
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    • 제33B권2호
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    • pp.56-64
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    • 1996
  • In the previous paper of this study, an incoherent intensity pattern of a conducting cylinder is obtained by averaging out the multi-frequency intensities of the time-harmonic fields scattered from this cylinder. in this paper, an incoherent imaging of a conducting cylinder is obtained via the back-projection of the incoherent intensity patterns calculated from the circular rotational measurement configuration. This imaging method is vlaidated by imaging a conducting circular and a conducting elliptic cylinder and the measurement conditions to get better image are investigated.

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