• Title/Summary/Keyword: Polar Mapping

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Rotation and Scale Invariant Face Detection Using Log-polar Mapping and Face Features (Log-polar변환과 얼굴특징추출을 이용한 크기 및 회전불변 얼굴인식)

  • Go Gi-Young;Kim Doo-Young
    • Journal of the Institute of Convergence Signal Processing
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    • v.6 no.1
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    • pp.15-22
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    • 2005
  • In this paper, we propose a face recognition system by using the CCD color image. We first get the face candidate image by using YCbCr color model and adaptive skin color information. And we use it initial curve of active contour model to extract face region. We use the Eye map and mouth map using color information for extracting facial feature from the face image. To obtain center point of Log-polar image, we use extracted facial feature from the face image. In order to obtain feature vectors, we use extracted coefficients from DCT and wavelet transform. To show the validity of the proposed method, we performed a face recognition using neural network with BP learning algorithm. Experimental results show that the proposed method is robuster with higher recogntion rate than the conventional method for the rotation and scale variant.

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A Least Squares Regression Model to Detect Quantitative Trait Loci with Polar Overdominance in a Cross of Outbred Breeds: Simulation

  • Kim, Jong-Joo;Dekkers, Jack C.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.11
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    • pp.1536-1544
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    • 2013
  • A least squares regression interval mapping model was derived to detect quantitative trait loci (QTL) with a unique mode of genomic imprinting, polar overdominance (POD), under a breed cross design model in outbred mammals. Tests to differentiate POD QTL from Mendelian, paternal or maternal expression QTL were also developed. To evaluate the power of the POD models and to determine the ability to differentiate POD from non-POD QTL, phenotypic data, marker data and a biallelic QTL were simulated on 512 F2 offspring. When tests for Mendelian versus parent-of-origin expression were performed, most POD QTL were classified as partially imprinted QTL. The application of the series of POD tests showed that more than 90% and 80% of medium and small POD QTL were declared as POD type. However, when breed-origin alleles were segregating in the grand parental breeds, the proportion of declared POD QTL decreased, which was more pronounced in a mating design with a small number of parents ($F_0$ and $F_1$). Non-POD QTL, i.e. with Mendelian or parent-of-origin expression (complete imprinting) inheritance, were well classified (>90%) as non-POD QTL, except for QTL with small effects and paternal or maternal expression in the design with a small number of parents, for which spurious POD QTL were declared.

Sampling Bias of Discontinuity Orientation Measurements for Rock Slope Design in Linear Sampling Technique : A Case Study of Rock Slopes in Western North Carolina (선형 측정 기법에 의해 발생하는 불연속면 방향성의 왜곡 : 서부 North Carolina의 암반 사면에서의 예)

  • 박혁진
    • Journal of the Korean Geotechnical Society
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    • v.16 no.1
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    • pp.145-155
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    • 2000
  • Orientation data of discontinuities are of paramount importance for rock slope stability studies because they control the possibility of unstable conditions or excessive deformation. Most orientation data are collected by using linear sampling techniques, such as borehole fracture mapping and the detailed scanline method (outcrop mapping). However, these data, acquired by the above linear sampling techniques, are subjected to bias, owing to the orientation of the sampling line. Even though a weighting factor is applied to orientation data in order to reduce this bias, the bias will not be significantly reduced when certain sampling orientations are involved. That is, if the linear sampling orientation nearly parallels the discontinuity orientation, most discontinuities orientation data which are parallel to sampling line will be excluded from the survey result. This phenomenon can cause serious misinterpretation of discontinuity orientation data because critical information is omitted. In the case study, orientation data collected by using the borehole fracture mapping method (vertical scanline) were compared to those based on orientation data from the detailed scanline method (horizontal scanline). Differences in results for the two procedures revealed a concern that a representative orientation of discontinuities was not accomplished. Equal-area, polar stereo nets were used to determine the distribution of dip angles and to compare the data distribution fur the borehole method versus those for the scanline method.

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A Modified LPM-Based Image Watermarking in the DCT/DFT Domain (수정된 LPM을 이용한 DCT, DFT 기반 이미지 워터마킹)

  • Lee, Myung-Ho;Kwon, Oh-Jin
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.239-240
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    • 2007
  • We suggest an image watermarking algorithm. We perform the modified Log-Polar Mapping (LPM) and the DFT/DCT on the original image and embed the watermark. Binary images are used for watermarks. Watermarking strength is adaptively adjusted depend on the mapped data Experimental results show that this method is robust to JPEG and rotation distortions.

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A collision-free path planning using linear parametric curve based on geometry mapping of obstacles (장애물의 기하투영에 의한 일차매개곡선을 이용한 충돌회피 경로계획)

  • Nam-Gung, In
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.12
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    • pp.1992-2007
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    • 1997
  • A new algorithm for planning a collision-free path is developed based on linear prametric curve. In this paper robot is assumed to a point, and two linear parametric curve is used to construct a path connecting start and goal point, in which single intermediate connection point between start and goal point is considered. The intermediate connection point is set in polar coordinate(${\theta}{\delta}$) , and the interference between path and obstacle is mapped into CPS(connection point space), which is defined a CWS GM(circular work space geometry mapping). GM of all obstacles in workspace creates overlapping images of obstacle in CPS(Connection Point Space). The GM for all obstacles produces overlapping images of obstacle in CPS. The empty area of CPS that is not occupied by obstacle images represents collision-free paths in Euclidian Space. A GM based on connection point in elliptic coordinate(${\theta}{\delta}$) is also developed in that the total length of path is depend only on the variable .delta.. Hence in EWS GM(elliptic work space geometry mapping), increasing .delta. and finding the value of .delta. for collision-free path, the shortest path can be searched without carring out whole GM. The GM of obstacles expersses all possible collision-free path as empty spaces in CPS. If there is no empty space available in CPS, it indicates that path planning is not possible with given number of connection points, i.e. path planning is failed, and it is necessary to increase the number of connection point. A general case collision-free path planning is possible by appling GM to configuration space obstacles. Simulation of GM of obstacles in Euclidian space is carried out to measure performance of algorithm and the resulting obstacle images are reported.

Global Mapping of Saturnian Haze

  • Park, Jaekyun;Kim, Sang Joon;Melin, Henrik;Stallard, Tom S.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.82.1-82.1
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    • 2019
  • Recent analyses of spectro-images of Saturn observed by Visual and Infrared Mapping Spectrometer (VIMS)/Cassini revealed altitudinal distributions of the spectral structure of haze in Saturn's south-polar regions (Kim et al., 2018) and at $55^{\circ}N$ latitude (Kim et al., 2012). However, other regions of Saturn still have not been investigated. We derived series of high-spatial resolution VIMS images of Saturn's limb at various latitudes. Using our developed code, the altitudinal intensity profiles of $3.3-{\mu}m$ emission and H3+ through different latitudes were plotted. Then we obtained the averaged vertical spectra of $3.3-{\mu}m$ emission which is all blended with fluorescent methane and hydrocarbon haze. The vertically-resolved spectra were measured from the limb of Saturn in 50km intervals to see altitudinal variance. We will present a comparison of spectral structures of $3.3-{\mu}m$ emission with different latitudes. Further investigation using radiative transfer to extract adjacent fluorescent CH4, C2H6, and H3+ is needed to derive spectral structure of pure haze. We look forward to a better understanding of aging process in a global view.

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Impervious Surface Mapping of Cheongju by Using RapidEye Satellite Imagery (RapidEye 위성영상을 이용한 청주시의 불투수면지도 생성기법)

  • Park, Hong Lyun;Choi, Jae Wan;Choi, Seok Keun
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.1
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    • pp.71-79
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    • 2014
  • Most researches have created the impervious surface map by using low-spatial-resolution satellite imagery and are inefficient to generate the object-based impervious map with a broad area. In this study, segment-based impervious surface mapping algorithm is proposed using the RapidEye satellite imagery in order to map impervious area. At first, additional bands are generated by using TOA reflectance conversion RapidEye data. And then, shadow and water class are extracted using training data of converted reflectance image. Object-based impervious surface can be generated by spectral mixture analysis based on land cover map of Ministry of Environment with medium scale, in the case of other classes except shadow and water classes. The experiment shows that result by our method represents high classification accuracy compared to reference data, quantitatively.

RST Invariant Digital Watermarking Based on Image Representation by Wedges and Rings

  • Kim, Ki-Jung
    • International Journal of Contents
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    • v.5 no.2
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    • pp.26-31
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    • 2009
  • This paper describes a new image watermarking scheme invariant to rotation, scaling and translation (RST) attacks. For obtaining the invariance properties we propose to present an image of watermark by wedges and rings to convert its rotation to shift and then utilize the shift invariance property of the Direct Fourier Transform (DFT). But in contrast to conversional schemes based on the Fourier-Mellin transform (FMT), we do not use a log-polar mapping (LPM). As a result, our scheme preserves high quality of original image since it is not underwent to LPM For withstanding against JPEG compression, noise addition and low-pass (LP) filtering attacks a low frequency watermark is embedded into middle frequencies of the original image. Experiments with various attacks show the robustness of the proposed scheme.

GLOBAL MAPPING OF NEAR-EARTH MAGNETIC FIELDS MEASURED BY KITSAT-1 AND KITSAT-2 (KITSAT-1과 KITSAT-2에서 관측한 지구자기장의 분포)

  • 표유선;이동훈;민경욱
    • Journal of Astronomy and Space Sciences
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    • v.11 no.1
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    • pp.81-92
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    • 1994
  • The magnetic field measurements from the KitSat-1 and KitSat-2 were tested by comparing with the IGRF model. The magnetic data have been collected by a three-axis fluxgate magnetometer on each satellite at an latitude of 1,325 km and 820 km, respectively. To avoid highly variable magnetic disturbances at the polar region, the field map has been within the limits of 50 degrees in latitude. Each data is averaged over the square of $5{\times}5$ degrees in both latitude and longitude. In these results, the relatively quiet periods were selected and the sampling rate was 30 seconds. It is shown that the results from these measurements are consistent with the IGRF map over the global surface map.

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PROPOSAL OF AMPLITUDE ONLY LOGARITHMIC RADON DESCRIPTER -A PERFORMANCE COMPARISON OF MATCHING SCORE-

  • Hasegawa, Makoto
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.450-455
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    • 2009
  • Amplitude-only logarithmic Radon transform (ALR transform) for pattern matching is proposed. This method provides robustness for object translation, scaling, and rotation. An ALR image is invariant even if objects are translated in a picture. For the object scaling and rotation, the ALR image is merely translated. The objects are identified using a phase-only matched filter to the ALR image. The ratio of size, the difference of rotation angle, and the position between the two objects are detected. Our pattern matching procedure is described, herein, and its simulation is executed. We compare matching scores with the Fourier-Mellin transform, and the general phase-only matched filter.

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