• Title/Summary/Keyword: Rotation Transform

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Rotation Angle Estimation of Multichannel Images (다채널 이미지의 회전각 추정)

  • Lee Bong-Kyu;Yang Yo-Han
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.6
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    • pp.267-271
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    • 2002
  • The Hotelling transform is based on statistical properties of an image. The principal uses of this transform are in data compression. The basic concept of the Hotelling transform is that the choice of basis vectors pointing the direction of maximum variance of the data. This property can be used for rotation normalization. Many objects of interest in pattern recognition applications can be easily standardized by performing a rotation normalization that aligns the coordinate axes with the axes of maximum variance of the pixels in the object. However, this transform can not be used to rotation normalization of color images directly. In this paper, we propose a new method for rotation normalization of color images based on the Hotelling transform. The Hotelling transform is performed to calculate basis vectors of each channel. Then the summation of vectors of all channels are processed. Rotation normalization is performed using the result of summation of vectors. Experimental results showed the proposed method can be used for rotation normalization of color images effectively.

Stereo Matching for PCB Image (PCB 영상의 스테레오 정합)

  • 최춘호;문철홍
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.943-946
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    • 1998
  • In this paper, we applied FFT to PCB Images, cutting unnecessary singals and noise, moving the starting point to center of image and used rotaion transform. from the detected edge Hough Transform identify the length, but not the angle, so we matched PCB images with using rotation transform to identify length and angle. After rotation transform we employ Least Squared Method to exact stereo matching.

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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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Performance Analysis of a Rotation-Transform Aided QPSK over Impulsive Noise Using Rieman Integral over Voronoi Cell (보로노이 셀에서 리만 적분을 이용한 임펄스 잡음 환경에서 동작하는 회전 변환 QPSK 기법의 성능 해석)

  • Choi, Byoungjo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.3
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    • pp.224-239
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    • 2013
  • An exact performance analysis of an ML detector for a 2-dimensional rotation-transform aided QPSK system operating over an impulsive noise environment is presented using Rieman integrals of a two-dimensional Gaussian Q-function over Voronoi cells. A set of interesting features of the Voronoi cells is also characterised systematically. An optimum rotation angle yielding the minimum BER is also studied. The differences between the proposed exact method and the previous approximate analysis method are investigated in terms of the corresponding BERs and the derived optimum angles.

Rotation and Translation Invariant Feature Extraction Using Angular Projection in Frequency Domain (주파수 영역에서 각도 투영법을 이용한 회전 및 천이 불변 특징 추출)

  • Lee, Bum-Shik;Kim, Mun-Churl
    • Journal of the HCI Society of Korea
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    • v.1 no.2
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    • pp.27-33
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    • 2006
  • This paper presents a new approach to translation and rotation invariant feature extraction for image texture retrieval. For the rotation invariant feature extraction, we invent angular projection along angular frequency in Polar coordinate system. The translation and rotation invariant feature vector for representing texture images is constructed by the averaged magnitude and the standard deviations of the magnitude of the Fourier transform spectrum obtained by the proposed angular projection. In order to easily implement the angular projection, the Radon transform is employed to obtain the Fourier transform spectrum of images in the Polar coordinate system. Then, angular projection is applied to extract the feature vector. We present our experimental results to show the robustness against the image rotation and the discriminatory capability for different texture images using MPEG-7 data set. Our Experiment result shows that the proposed rotation and translation invariant feature vector is effective in retrieval performance for the texture images with homogeneity, isotropy and local directionality.

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An optical object recognition system using log-polar coordinate transform of power spectrum and NJTC (파워스펙트럼의 Log-polar 좌표변환 및 NJTC를 이용한 광 물체 인식 시스템)

  • 이상이;채호병;이승현;김은수
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.6
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    • pp.178-188
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    • 1996
  • In this paper, we propose a new opto-digital object recognition system which has rotation, scale, and shift invariant characteristics. The fourier power spectrum of the object image is modified to get shift invariance. The log-polar transform is used for rotation and scale invariance. And the decision of similarities is performed by nonlinear joint transform correlator (NJTC) that can control the ratio of phase and amplitude signals. Experimental verification of th eproposed optical object recognition system is presented.

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Correction of Rotated Objects in Medical Images Using the Mojette Transform (모젯 변환을 이용한 의료 영상의 회전 물체 보정)

  • Jung, Hyang-Mi;Kim, Ji-Hong
    • Journal of Korea Multimedia Society
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    • v.15 no.11
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    • pp.1341-1348
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    • 2012
  • In this paper, an efficient scheme for correcting rotated objects in medical images using the Mojette transform is presented. The Mojette transform is a kind of discrete Radon transform, where the transform domain is represented by a set of projections. The Mojette transform currently studied in the image compression area is modified for detecting the rotation angle of objects in medical images. First, in order to find accurate rotation angle, the projection value in the Mojette transform is determined by using pixels on the projection line and in addition the linear interpolation of pixels adjacent to the line. Second, at each projection angle, only one projection is implemented for reducing the amount of the calculation in the process of the Mojette transform. Finally, the projection in the Mojette transform is carried out at the predetermined ROI(Region Of Interest) at which the objects are not cropped or added by rotating the image. The simulation results show that the proposed method has good performance for correcting the rotation angle in medical images.

Geometric Transform-Invariant Gait Recognition Using Modified Radon Transform (변형된 라돈 변환을 이용한 기하학적 형태 불변 보행인식)

  • Jang, Sang-Sik;Lee, Seung-Won;Paik, Joon-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.4
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    • pp.67-75
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    • 2011
  • This paper presents a scale and rotation-invariant gait recognition method using R-transform, which is computed by projecting squared coefficients of Radon transform. Since R-transform is invariant to translation, rotation, and scaling, it particularly suitable for extracting object poses without camera calibration. Coefficients of R-transform are used to compute correlation, and the maximum correlation value determines the similarity between two gait images. The proposed method requires neither camera calibration nor geometric compensation, and as a result, it makes robust gait recognition possible without additional compensation for translation, rotation, and scaling.

Visual Object Tracking using Surface Fitting for Scale and Rotation Estimation

  • Wang, Yuhao;Ma, Jun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.5
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    • pp.1744-1760
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    • 2021
  • Since correlation filter appeared in the field of object tracking, it plays an increasingly vital role due to its excellent performance. Although many sophisticated trackers have been successfully applied to track the object accurately, very few of them attaches importance to the scale and rotation estimation. In order to address the above limitation, we propose a novel method combined with Fourier-Mellin transform and confidence evaluation strategy for robust object tracking. In the first place, we construct a correlation filter to locate the target object precisely. Then, a log-polar technique is used in the Fourier-Mellin transform to cope with the rotation and scale changes. In order to achieve subpixel accuracy, we come up with an efficient surface fitting mechanism to obtain the optimal calculation result. In addition, we introduce a confidence evaluation strategy modeled on the output response, which can decrease the impact of image noise and perform as a criterion to evaluate the target model stability. Experimental experiments on OTB100 demonstrate that the proposed algorithm achieves superior capability in success plots and precision plots of OPE, which is 10.8% points and 8.6% points than those of KCF. Besides, our method performs favorably against the others in terms of SRE and TRE validation schemes, which shows the superiority of our proposed algorithm in scale and rotation evaluation.

A Rotation Resistant Logo Embedding Watermark on Frequency Domain (회전 변환에 강인한 주파수 영역 로고 삽입 워터마크 방법)

  • Lee, In-Jung;Lee, Hyoung;Yoo, Hye-Rim;Min, Joon-Young
    • Journal of Information Technology Applications and Management
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    • v.14 no.1
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    • pp.137-144
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    • 2007
  • In this paper, we propose a rotation resistant robust logo embedding watermarking technique. Geometric manipulations make the detection process very complex and difficult. Watermark embedding in the normalized image directly suffers from smoothing effect due to the interpolation during the image normalization. This can be avoided by estimating the transform parameters using image normalization angle and moments, instead of embedding in the normalized image. Conventional rotation resistant schemes that use full frame transform. In this paper we adopt DCT and calculate masking using a spatio-frequency localization of the $8{\times}8$ block DCT coefficients. Experimental results show that the proposed algorithm is robust against rotation process.

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