Results 171 to 180 of about 3,627 (192)

Range Instantaneous Doppler ISAR imaging based on FRFT

2010 International Symposium on Signals, Systems and Electronics, 2010
Very high resolution inverse synthetic aperture radar (ISAR) imaging of maneuvering targets is a complicated task. Due to the phase error caused by target's non-cooperative motion, we can't use conventional Fourier transform in ISAR imaging reconstruction.
null Huang Jianjia, null Yali Qin, null Hongliang Ren, null Wen Hao   +3 more
openaire   +1 more source

2D-FRFT Based Rotation Invariant Digital Image Watermarking

2012 IEEE International Symposium on Multimedia, 2012
The extraction of rotation invariant representation is important for many signal processing problems such as image analysis, computer vision, and pattern recognition. In this paper, we present a systematic analysis of the Two-Dimensional Fractional Fourier Transform (2D-FRFT), and show that under certain conditions, the 2D-FRFT technique possesses the ...
Lei Gao, Lin Qi, Shouyi Yang, Yongjin Wang, Tie Yun, Ling Guan   +5 more
openaire   +1 more source

Distribution of FRFT Coefficients of Natural Images

2015
For the convenience of providing temporal and spectral information by a single variable, fractional Fourier transformation (FRFT) is more and more applied to image processing recently. This paper focuses on the statistical regularity of FRFT coefficients of natural images and proposes that the real and imaginary parts of FRFT coefficients of natural ...
Li Jiang, Guichi Liu, Lin Qi
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Robustness of fractional order for FRFT-OFDM systems

2015 IEEE International Conference on Communication Software and Networks (ICCSN), 2015
Fractional Fourier transform (FRFT) has been widely used in orthogonal frequency division (OFDM) systems to combat the doubly dispersive channels. The sensitivity of the fractional order is a serious problem. In this paper, we derive the closed form of the variable order and its optimal value based on the mathematical expression in the FRFT-OFDM ...
null Pengfei Shi, null Dongjie Qi, null Miao Li, null Hao Huan   +3 more
openaire   +1 more source

Encoding of Color Images in DWT domain using FrFT

Proceedings of the International Conference on Advances in Information Communication Technology & Computing - AICTC '16, 2016
This paper presents a new color image encoding and decoding technique using Fractional Fourier Transform (FrFT) and Discrete Wavelet Transform (DWT). In proposed work, all three planes of color images are encoded using subbands of DWT and parameters of FrFT.
Kshitij Agrawal, Shalini Batra
openaire   +1 more source

A new cross-range scaling algorithm based on FrFT

IEEE 10th INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING PROCEEDINGS, 2010
Inverse synthetic aperture radar (ISAR) generates two dimensional high resolution images of targets in range-Doppler domain. In order to determine the cross-range dimension of the target or implement polar formatting to reconstruct more focused ISAR images, estimation of the rotation angle is required.
Jianjun Gao, Fulin Su
openaire   +1 more source

Novel Fragile FRFT Watermarking Algorithm Based on Blocking Method

2012 International Conference on Computing, Measurement, Control and Sensor Network, 2012
novel fragile watermarking algorithm is proposed based on the Fractional Fourier Transform (FRFT) and the blocking method in this paper. Chaotic sequence is converted into a binary 0, 1 sequence to be used as the watermarking information. The blocking method for fragile watermarking algorithm is used to generate the initial value of the chaotic ...
Chang-Yong Liu, Lin-Lin Tang, Jeng-Shyang Pan   +2 more
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Chirp FSK based on FRFT for underwater acoustic communication

2017 7th IEEE International Conference on Electronics Information and Emergency Communication (ICEIEC), 2017
Chirp spread spectrum has poorly rate of transmission in shallow water acoustic channel because of its channel parameters in the random changes. This paper proposes a novel chirp spread spectrum modulation system based on the explicit relationship between fractional Fourier transform (FRFT) properties of Chirp-FSK signals and their parameters ...
Zhang Kaihan, Chen Keyu, Yuan Fei, Yi Jinwang   +3 more
openaire   +1 more source

A novel analysis of PAPR of FRFT-OFDM system

2015 10th International Conference on Communications and Networking in China (ChinaCom), 2015
As is shown that the multicarrier system based on fractional Fourier transform (FRFT) has advantages over orthogonal frequency division multiplexing (OFDM) system in performance of peak-to-average power ratio (PAPR). In this paper, precise expressions of PAPR of FRFT-OFDM scheme and traditional OFDM scheme are derived and verified by simulations, as an
Zhenduo Wang, Lin Mei, null Xiaolu Wang, null Shaobo Wang, null Naitong Zhang   +4 more
openaire   +1 more source

Image Computing: Fractional Spectra and Circular Moments via FrFT

2009 Fifth International Conference on Natural Computation, 2009
In image computing, feature extraction plays a key part for image pattern classification. In this article we adopt discrete Fractional Fourier Transform (FrFT) for fractional feature extraction. Firstly, a criterion is proposed to determine the FrFT order for an image class so that it may be optimally discriminated from other classes in the FrFT domain,
Benyong Liu, Jing Zhang
openaire   +1 more source