• Title/Summary/Keyword: affine transformation

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CERTAIN INFINITESIMAL TRANSFORMATIONS ON QUATERNIONIC KAHLERIAN MANIFOLDS

  • JIN SUK PAK;DAE WON YOON
    • Communications of the Korean Mathematical Society
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    • v.13 no.4
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    • pp.817-823
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    • 1998
  • In the present paper, we study conformal and projective Killing vector fields and infinitesimal Q-transformations on a quaternionic Kahlerian manifold, and prove that an infinitesimal conformal or projective automorphism in a compact quaternionic Kahlerian manifold is necessarily infinitesimal automorphism.

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The Study on Coordinate Transformation for Updating of Digital Map from Construction Drawing Data (건설도면 자료의 수치지도 갱신을 위한 좌표체계 부여에 관한 연구)

  • Park, Seung-Yong;Lee, Jae-Bin;Park, Woo-Jin;Yu, Ki-Yun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.2
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    • pp.281-288
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    • 2009
  • In the paper, we try to develop the methodology for updating road networks of large-scale digital maps by using construction drawing data. For the purpose, it is pre-requite step to merge road networks detached in CAD drawing data. As such, tie points are identified in neighboring drawings and used for solving the parameters of 2D conformal transformation between drawings. Then, the merged road network in CAD data is transformed to the coordinate system of digital maps. In the process, IPs in the drawings are considered as control information and 2D affine transformation is selected for coordinate transformation. Through the experiments with real dataset, we can identify that the developed method is valid and generally applicable.

Proposing Shape Alignment for an Improved Active Shape Model (ASM의 성능향상을 위한 형태 정렬 방식 제안)

  • Hahn, Hee-Il
    • Journal of Korea Multimedia Society
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    • v.15 no.1
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    • pp.63-70
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    • 2012
  • In this paper an extension to an original active shape model(ASM) for facial feature extraction is presented. The original ASM suffers from poor shape alignment by aligning the shape model to a new instant of the object in a given image using a simple similarity transformation. It exploits only informations such as scale, rotation and shift in horizontal and vertical directions, which does not cope effectively with the complex pose variation. To solve the problem, new shape alignment with 6 degrees of freedom is derived, which corresponds to an affine transformation. Another extension is to speed up the calculation of the Mahalanobis distance for 2-D profiles by trimming the profile covariance matrices. Extensive experiment is conducted with several images of varying poses to check the performance of the proposed method to segment the human faces.

Comparison between the General Least Squares method and the Total Least Squares method through coordinate transformation (좌표변환을 통한 일반최소제곱법과 토탈최소제곱법 비교연구)

  • 박영무;김병국
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.9-16
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    • 2004
  • Performing adjustments where the observation equations involve more than a single measurement are General Least Squares(GLS) and Total Least Squares(TLS). This paper introduces theory of the GLS and TLS and compared experimentally accuracy and efficiency of those through 2D conformal coordinate transformation and 2D affine coordinate transformation. In conclusion, in case of 2D coordinate transformation, GLS can produce a little more accurate and efficient than TLS. In survey fields, The GLS and TLS can be used cooperatively for adjusting the actual coordinate measurements.

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Image Registration Improvement Based-on FFT Techniques with the Affine Transform Estimation

  • Wisetphanichkij, Sompong;Pasomkusolsil, Sanchaiya;Dejhan, Kobchai;Cheevasuvit, Fusak;Mitatha, Somsak;Sra-Ium, Napat;Vorrawat, Vinai;Pienvijarnpong, Chanchai
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.260-262
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    • 2003
  • New Image registration techniques are developed for determining geometric distortions between two images of the same scene. First, the properties of the Fourier transform of a two dimensional function under the affine transformation are given. As a result, techniques for the estimation of the coefficients of the distortion model using the spectral frequency information are developed. Image registration can be achieved by applying the fast Fourier transform (FFT) technique for cross correlation of misregistered imagery to determine spatial distances. The correlation results may be rather broad, making detection of the peak difficult, what can be suppressed by enhancing cross-correlation technique. Yield greatly improves the delectability and high precision of image misregistration.

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Robust Synchronization Recovery of a Periodic Watermark Using Radon Transform (Radon 변환을 이용한 주기적인 워터마크 패턴의 동기 복원 방법)

  • 서진수;유창동
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.1
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    • pp.124-129
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    • 2003
  • A novel watermark registration method based on Radon transform for self-referencing watermark is presented. The novel method was successful in registering the watermark of the image that has undergone affine transformations and severe lossy compression, whereas the conventional method based on peak detection failed to register the watermark.

A Study on Application of Coordinates Transformation Methods on Parcel and Forestry Map Connection (지적도와 임야도접합을 위한 좌표변환방법 적용에 관한 연구)

  • 강준묵;조성호;김성진
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.4
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    • pp.405-413
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    • 2002
  • It is crucial that we should set proper standards capable of efficiently handling new corrections of maps, connections of edges on the maps, administrative districts, and inter-scale connections in order to make serial cadastral maps. This study drew a two dimensional Parameter using an indent point, as a Review Control Point, on forest screening line or boundary line of administrative district. The study also introduced a few different transformations such as Affine Transformation, N-Degree Polynomial Transformation, and Projective Transformation, the two dimensional transformation methods to apply them to the connection of cadastal·forestry maps and the connection of parcels between the administrative districts, on the forestry map designed by discretionary edges on the maps per district unit with parcel numbers and tried to apply the coordinates transformation method to connections of maps to make serial cadastral maps.

Registration between High-resolution Optical and SAR Images Using linear Features (선형정보를 이용한 고해상도 광학영상과 SAR 영상 간 기하보정)

  • Han, You-Kyung;Kim, Duk-Jin;Kim, Yong-Il
    • Korean Journal of Remote Sensing
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    • v.27 no.2
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    • pp.141-150
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    • 2011
  • Precise image-to-image registration is required to process multi-sensor data together. The purpose of this paper is to develop an algorithm that register between high-resolution optical and SAR images using linear features. As a pre-processing step, initial alignment was fulfilled using manually selected tie points to remove any dislocations caused by scale difference, rotation, and translation of images. Canny edge operator was applied to both images to extract linear features. These features were used to design a cost function that finds matching points based on their similarity. Outliers having larger geometric differences than general matching points were eliminated. The remaining points were used to construct a new transformation model, which was combined the piecewise linear function with the global affine transformation, and applied to increase the accuracy of geometric correction.

Fast speaker adaptation using extended diagonal linear transformation for deep neural networks

  • Kim, Donghyun;Kim, Sanghun
    • ETRI Journal
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    • v.41 no.1
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    • pp.109-116
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    • 2019
  • This paper explores new techniques that are based on a hidden-layer linear transformation for fast speaker adaptation used in deep neural networks (DNNs). Conventional methods using affine transformations are ineffective because they require a relatively large number of parameters to perform. Meanwhile, methods that employ singular-value decomposition (SVD) are utilized because they are effective at reducing adaptive parameters. However, a matrix decomposition is computationally expensive when using online services. We propose the use of an extended diagonal linear transformation method to minimize adaptation parameters without SVD to increase the performance level for tasks that require smaller degrees of adaptation. In Korean large vocabulary continuous speech recognition (LVCSR) tasks, the proposed method shows significant improvements with error-reduction rates of 8.4% and 17.1% in five and 50 conversational sentence adaptations, respectively. Compared with the adaptation methods using SVD, there is an increased recognition performance with fewer parameters.

HARMONIC TRANSFORMATIONS OF THE HYPERBOLIC PLANE

  • Park, Joon-Sik
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.4
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    • pp.771-776
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    • 2009
  • Let (H, g) denote the upper half plane in $R^2$ with the Riemannian metric g := ($(dx)^2$ + $(dy)^2$)$/y^2$. First of all we get a necessary and sufficient condition for a diffeomorphism $\phi$ of (H, g) to be a harmonic map. And, we obtain the fact that if a diffeomorphism $\phi$ of (H, g) is a harmonic function, then the following facts are equivalent: (1) $\phi$ is a harmonic map; (2) $\phi$ is an affine transformation; (3) $\phi$ is an isometry (motion).

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