• Title/Summary/Keyword: Geometric similarity

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Evaluation of the Optimum Interpolation for Creating Hydraulic Model from Close Range Digital Photogrammetry (근접수치사진측량으로 수리모형해석에 적용 시 최적보간법 평가)

  • Choi Hyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.23 no.3
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    • pp.251-260
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    • 2005
  • The Development of CCD has contributed to great advancement in mapping technology with giving benefits to research community of photogrammetry. The purpose of this paper is to find the best selection of interpolation method for creating a terrain model form close range digital photogrammetry. T-test as a kind of statistical analysis was conducted to analyze the similarity of hydraulic model with close range digital photogrammetry and trigonometric leveling. Also, many interpolation methods such as inverse distance, kriging, nearest neighbor and TIN about the hydraulic model interpolation were conducted to compare the results for computer to display actual terrain an optimum interpolation of the digital elevation model form close range digital photogrammetry. The results revealed that kriging and TIN interpolation were efficient methods to judge the hazard interpolation law by analyzing geometric similarity of hydraulic model against hydraulic model application.

Landmark Recognition Method based on Geometric Invariant Vectors (기하학적 불변벡터기반 랜드마크 인식방법)

  • Cha Jeong-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.3 s.35
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    • pp.173-182
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    • 2005
  • In this paper, we propose a landmark recognition method which is irrelevant to the camera viewpoint on the navigation for localization. Features in previous research is variable to camera viewpoint, therefore due to the wealth of information, extraction of visual landmarks for positioning is not an easy task. The proposed method in this paper, has the three following stages; first, extraction of features, second, learning and recognition, third, matching. In the feature extraction stage, we set the interest areas of the image. where we extract the corner points. And then, we extract features more accurate and resistant to noise through statistical analysis of a small eigenvalue. In learning and recognition stage, we form robust feature models by testing whether the feature model consisted of five corner points is an invariant feature irrelevant to viewpoint. In the matching stage, we reduce time complexity and find correspondence accurately by matching method using similarity evaluation function and Graham search method. In the experiments, we compare and analyse the proposed method with existing methods by using various indoor images to demonstrate the superiority of the proposed methods.

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Line Matching Method for Linking Wayfinding Process with the Road Name Address System (길찾기 과정의 도로명주소 체계 연계를 위한 선형 객체 매칭 방법)

  • Bang, Yoon Sik;Yu, Ki Yun
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.4
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    • pp.115-123
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    • 2016
  • The road name address system has been in effect in Korea since 2012. However, the existing address system is still being used in many fields because of the difference between the spatial awareness of people and the road name address system. For the spatial awareness based on the road name address system, various spatial datasets in daily life should be referenced by the road names. The goal of this paper is to link the road name address system with the wayfinding process, which is closely related to the spatial awareness. To achieve our goal, we designed and implemented a geometric matching method for spatial data sets. This method generates network neighborhoods from road objects in the 'road name address map' and the 'pedestrian network data'. Then it computes the geometric similarities between the neighborhoods to identify corresponding road name for each object in the network data. The performance by F0.5 was assessed at 0.936 and it was improved to 0.978 by the manual check for 10% of the test data selected by the similarity. By help of our method, the road name address system can be utilized in the wayfinding services, and further in the spatial awareness of people.

Automatic Co-registration of Existing Building Models and Digital Image (건물 모델과 디지털 영상간의 자동정합 방법)

  • Jung, Jae-Wook;Sohn, Gun-Ho;Armenakis, Costas
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.1
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    • pp.125-132
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    • 2010
  • With recent advancement of remote sensing technology, a variety of data acquisition over the same area is achievable. An automated co-registration of heterogeneous airborne images is a critical step for change detection. This paper describes an automatic method for co-registration between digital image and existing building model. Optimal building models for co-registration purpose are extracted as primitives from existing building model database. A set of homologous features between straight lines extracted from aerial digital image and model primitive are computed based on geometric similarity function. With obtained homologous features, EO parameter is recomputed using least square method. The result shows that die suggested method automatically co-register two data set in a reliable manner.

3D Non-Rigid Registration for Abdominal PET-CT and MR Images Using Mutual Information and Independent Component Analysis

  • Lee, Hakjae;Chun, Jaehee;Lee, Kisung;Kim, Kyeong Min
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.5
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    • pp.311-317
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    • 2015
  • The aim of this study is to develop a 3D registration algorithm for positron emission tomography/computed tomography (PET/CT) and magnetic resonance (MR) images acquired from independent PET/CT and MR imaging systems. Combined PET/CT images provide anatomic and functional information, and MR images have high resolution for soft tissue. With the registration technique, the strengths of each modality image can be combined to achieve higher performance in diagnosis and radiotherapy planning. The proposed method consists of two stages: normalized mutual information (NMI)-based global matching and independent component analysis (ICA)-based refinement. In global matching, the field of view of the CT and MR images are adjusted to the same size in the preprocessing step. Then, the target image is geometrically transformed, and the similarities between the two images are measured with NMI. The optimization step updates the transformation parameters to efficiently find the best matched parameter set. In the refinement stage, ICA planes from the windowed image slices are extracted and the similarity between the images is measured to determine the transformation parameters of the control points. B-spline. based freeform deformation is performed for the geometric transformation. The results show good agreement between PET/CT and MR images.

The Remodelling of Hydraulic Structure in a Distribution Channel for Improving the Equality of the Flow Distribution (I): Design Using CFD Simulation (수리구조 개선을 통한 분배수로 균등분배 성능 향상에 관한 연구(I) : CFD를 이용한 설계 중심으로)

  • Park, No-Suk;Kim, Seong-Su;Park, Jong-Yoon;Yoon, Cheol-Hwan;Kim, Chung-Hwan
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.5
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    • pp.571-579
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    • 2007
  • This study was conducted to qualify the equality of the flow distribution from open channel between rapid mixing basin and flocculation basins in a domestic full-scale water treatment plant, and suggest a remedy for improving the equality. In order to evaluate the feasibility of the suggested remedy, computational fluid dynamics (CFD) technique are used, and for verifying the CFD simulation results wet tests were carried out for the pilot scale channel based on geometric similarity. From the results of CFD simulation and wet tests, it was investigated that the modification of hydraulic structure in the distribution channel, which is to install the longitudinal orifice baffle in flow direction, could improve the equality of the flow distribution. Also, in the case that Froude number is relatively small (Froude number <<0.03), the open ratio of orifices on the installed baffle hardly affects the equality of flow distribution.

Recognition of Traffic Signs using Wavelet Transform and Shape Information (웨이블릿 변환과 형태 정보를 이용한 교통 표지판 인식)

  • 오준택;곽현욱;김욱현
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.125-134
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    • 2004
  • This paper proposes a method for recognition of traffic signs using wavelet transform and shape information from the segmented traffic sign regions. It first segments traffic sign candidate regions by connected component algorithm from binary images, obtained by utilizing the RGB color ratio of each pixel in the image, and then extracts actual traffic sign regions based on their symmetries on X- and Y-axes. In the recognition stage, it utilizes shape information including moment edge correlogram and the number of crossings which concentric circular patterns from region center intersects with frequency information extracted by wavelet transform It finally performs recognition by measuring similarity with the templates in the database. The experimental results show the validity of the proposed method from geometric transformations and environmental factors.

A Study of the Aesthetics of Mimesis in 2000s Fashion (2000년대 패션에 표현된 미메시스 연구)

  • Yang, Su-Mi;Kwon, Mi-Jeong
    • Journal of the Korean Society of Costume
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    • v.59 no.10
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    • pp.38-50
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    • 2009
  • Since Homeros in Greece, Mimesis was thought to be an art to imitate the nature, and it means an imitation of the nature classically. Mimetic theories were set to be a kind of art work in the era of Renaissance, and the terminology of mimesis was widely used to replace it with an originality in the 15th century. The purpose of this study is to understand the aesthetics of mimesis expressed in 2000s fashion. For this purpose, I investigated the theories of the mimesis, categorized the definition, then applied those categories for 2000s fashion. Documentary studies were conducted through aesthetics, fashion books and demonstrative studies were processed by analyzing photos from collection fashion magazines and fashion site of internet. In the history of aesthetics, the mimesis could be defined into three categories; the similarity and the representation mimesis, the symbol mimesis and the abstraction mimesis. In fashion, the representation mimesis included a natural and a folk, a period that of 1900s and ancient representation mimesis. The symbol mimesis included psychology and fear symbol mimesis. The abstraction mimesis included hard color, a geometric simplification and distortion mimesis. Analysis on the mimesis expressed in 2000s modern fashion may provide an excellent method for understanding human aesthetic in costume.

Generation of Simulated Geospatial Images from Global Elevation Model and SPOT Ortho-Image

  • Park, Wan Yong;Eo, Yang Dam
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.3
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    • pp.217-223
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    • 2014
  • With precise sensor position, attitude element, and imaging resolution, a simulated geospatial image can be generated. In this study, a satellite image is simulated using SPOT ortho-image and global elevation data, and the geometric similarity between original and simulated images is analyzed. Using a SPOT panchromatic image and high-density elevation data from a 1/5K digital topographic map data an ortho-image with 10-meter resolution was produced. The simulated image was then generated by exterior orientation parameters and global elevation data (SRTM1, GDEM2). Experimental results showed that (1) the agreement of the image simulation between pixel location from the SRTM1/GDEM2 and high-resolution elevation data is above 99% within one pixel; (2) SRTM1 is closer than GDEM2 to high-resolution elevation data; (3) the location of error occurrence is caused by the elevation difference of topographical objects between high-density elevation data generated from the Digital Terrain Model (DTM) and Digital Surface Model (DSM)-based global elevation data. Error occurrences were typically found at river boundaries, in urban areas, and in forests. In conclusion, this study showed that global elevation data are of practical use in generating simulated images with 10-meter resolution.

LINKING EVALUATION OF SUBJECTIVE TIRE TESTS ON THE ROAD WITH OBJECTIVELY MEASURED DATA

  • Stumpf, H.W.
    • International Journal of Automotive Technology
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    • v.2 no.1
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    • pp.17-23
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    • 2001
  • Measurements of the initial values lead to an inverse and mathematically unprecisely formulated problem. A precise definition of an inverse problem is possible. It is to state a mathematical model of a physical process with clearly defined initial and exit values for the system behind the process. One can grasp the idea of an inverse problem by considering the tire as a copy of the objects of nature in a room with observations. Interpretation of nature is generally a result of an inverse problem. On one hand, the tire may be represented through the sensory organs and the nervous system as well as the experiences of the developer's existing apparatus of the projection of reality. On the other hand, it may be represented by a physical law or a model that can be confirmed or is to be refuted with the help of suitable measurements. During reconstruction of a measuring signal and the identification of a black box that can be assumed to be linear and causal, the tire becomes a first type Volterra integral equation of the convolution type. But measurements of the initial values are always fuzzy, the errors grow and the system behavior can no longer be forecasted. Thus, we have to deal with a chaotic system. This chaos produces fractals in a natural way. These are self-similar geometric structures. This self-similarity is clearly visible in the design.

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