Local Upsampling Fourier Transform for High Accuracy Image Rotation Estimation

A high accuracy rotation angle estimation algorithm based on Local Upsampling Fourier Transform (LUFT) is developed in this paper. The LUFT uses a hierarchical strategy to estimate the rotation, which consists of a transformation of rotation to translation, a fast coarse rotation estimation and a robust refinement stage as well. The coarse rotation is estimated through the conventional Phase Only Correlation (POC), then, it is refined by the resampling technique within a local neighborhood in frequency domain. Furthermore, as will be shown in many experiments, the LUFT can achieve high accuracy rotation estimation, where the accuracy is tunable to some extent. Specially, it is efficient and robust to noise.

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IDENTIFICATION OF INTERHARMONICS BASED ON WAVELET PACKET TRANSFORM

Actual Issues Of Energy ◽

10.25206/2686-6935-2021-3-1-31-36 ◽

2021 ◽

Vol 3 (1) ◽

pp. 031-036

Author(s):

S. A. GOROVOY ◽

◽

V. I. SKOROKHODOV ◽

D. I. PLOTNIKOV ◽

◽

...

Keyword(s):

Fourier Transform ◽

Simulation Model ◽

Frequency Domain ◽

Time Domain ◽

Wavelet Packet ◽

High Accuracy ◽

Wavelet Packet Transform ◽

Mathematical Apparatus ◽

Nonlinear Load ◽

The Time Domain

This paper deals with the analysis of interharmonics, which are due to the presence of a nonlinear load. The tool for the analysis was a mathematical apparatus - wavelet packet transform. Which has a number of advantages over the traditional Fourier transform. A simulation model was developed in Simulink to simulate a non-stationary non-sinusoidal mode. The use of the wavelet packet transform will allow to determine the mode parameters with high accuracy from the obtained wavelet coefficients. It also makes it possible to obtain information, both in the frequency domain of the signal and in the time domain.

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High Precision Image Rotation Angle Estimation with Periodicity of Pixel Variance

2013 Seventh International Conference on Image and Graphics ◽

10.1109/icig.2013.27 ◽

2013 ◽

Author(s):

Ruohan Qian ◽

Weihai Li ◽

Nenghai Yu ◽

Bin Liu

Keyword(s):

High Precision ◽

Rotation Angle ◽

Angle Estimation ◽

Image Rotation

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A High-Accuracy Rotation Estimation Algorithm Based on 1D Phase-Only Correlation

Lecture Notes in Computer Science - Image Analysis and Recognition ◽

10.1007/978-3-540-74260-9_19 ◽

2007 ◽

pp. 210-221 ◽

Cited By ~ 7

Author(s):

Sei Nagashima ◽

Koichi Ito ◽

Takafumi Aoki ◽

Hideaki Ishii ◽

Koji Kobayashi

Keyword(s):

Estimation Algorithm ◽

High Accuracy ◽

Rotation Estimation

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Replacing DWT with DTCWT in blind image rotation angle estimation

Electronic Imaging ◽

10.2352/issn.2470-1173.2021.4.mwsf-275 ◽

2021 ◽

Keyword(s):

International Symposium ◽

Fast Track ◽

Rotation Angle ◽

Angle Estimation ◽

Image Rotation ◽

Electronic Imaging ◽

Blind Image

Fast track article for IS&T International Symposium on Electronic Imaging 2021: Media Watermarking, Security, and Forensics 2021 proceedings.

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Rotation Angle Estimation of JPEG Compressed Image by Cyclic Spectrum Analysis

Electronics ◽

10.3390/electronics8121431 ◽

2019 ◽

Vol 8 (12) ◽

pp. 1431

Author(s):

Shuxian Dai ◽

Yujin Zhang ◽

Wanqing Song ◽

Fei Wu ◽

Lijun Zhang

Keyword(s):

Rotation Angle ◽

Absolute Error ◽

Algorithm Performance ◽

Angle Estimation ◽

Image Rotation ◽

Peak Point ◽

Shortest Distance ◽

Peak Points ◽

Peak Value ◽

Cyclic Spectrum

Image rotation is a common auxiliary method of image tampering, which can make the forged image more realistic from the geometric perspective. Most algorithms of image rotation angle estimation employ the peak value on the Fourier spectrum; however, JPEG post-processing brings additional peak interferences to the spectrum, which has a great impact on algorithm performance. In this paper, angle estimation is carried out for images compressed by JPEG. Firstly, the Fourier cyclic spectrum of image covariance is calculated, followed by semi-soft threshold wavelet transform to eliminate the block artefacts brought by JPEG compression. According to the shortest distance principle in the range of the limited amplitude, the processed cyclic spectral data are sorted to select the peak points. Finally, according to the selected peak point, the corresponding position coordinates of the theoretical peak point are found, and the rotation angle of the image is estimated by the theoretical peak point. Experimental results demonstrate that the average absolute error of the proposed algorithm is significantly lower than that of the state-of-the-art methods investigated, which highlights the promising potential of the proposed method as an image resampling detector in practical forensics applications.

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JOINT INTERPRETATION OF AIRBORNE ELECTROMAGNETIC DATA IN THE TIME DOMAIN AND FREQUENCY DOMAIN

Engineering survey ◽

10.25296/1997-8650-2018-12-7-8-76-83 ◽

2018 ◽

Vol 12 (7-8) ◽

pp. 76-83

Author(s):

E. V. KARSHAKOV ◽

J. MOILANEN

Keyword(s):

Fourier Transform ◽

Frequency Domain ◽

Time Domain ◽

Frequency Interval ◽

Single Spectrum ◽

Simultaneous Inversion ◽

Homogeneous Half Space ◽

Time Domain Data ◽

The Time Domain

Тhe advantage of combine processing of frequency domain and time domain data provided by the EQUATOR system is discussed. The heliborne complex has a towed transmitter, and, raised above it on the same cable a towed receiver. The excitation signal contains both pulsed and harmonic components. In fact, there are two independent transmitters operate in the system: one of them is a normal pulsed domain transmitter, with a half-sinusoidal pulse and a small "cut" on the falling edge, and the other one is a classical frequency domain transmitter at several specially selected frequencies. The received signal is first processed to a direct Fourier transform with high Q-factor detection at all significant frequencies. After that, in the spectral region, operations of converting the spectra of two sounding signals to a single spectrum of an ideal transmitter are performed. Than we do an inverse Fourier transform and return to the time domain. The detection of spectral components is done at a frequency band of several Hz, the receiver has the ability to perfectly suppress all sorts of extra-band noise. The detection bandwidth is several dozen times less the frequency interval between the harmonics, it turns out thatto achieve the same measurement quality of ground response without using out-of-band suppression you need several dozen times higher moment of airborne transmitting system. The data obtained from the model of a homogeneous half-space, a two-layered model, and a model of a horizontally layered medium is considered. A time-domain data makes it easier to detect a conductor in a relative insulator at greater depths. The data in the frequency domain gives more detailed information about subsurface. These conclusions are illustrated by the example of processing the survey data of the Republic of Rwanda in 2017. The simultaneous inversion of data in frequency domain and time domain can significantly improve the quality of interpretation.

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