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Single Image Enhancement in Sandstorm Weather via Tensor Least Square

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IEEE/CAA Journal of Automatica Sinica 2020年第6期7卷 1649-1661页

作者： guanlei xu Xiaotong Wang Xiaogang xu College of Computer and Information Engineering Zhejiang Gongshang UniversityHangzhou 310018China

In this paper,we present a tensor least square based model for sand/sandstorm removal in *** main contributions of this paper are as ***,an important intrinsic natural feature of outdoor scenes free of sand/sandstorm is found that the outlines in RGB channels are somewise similar,which discloses the physical validation using the tensor instead of the ***,a tensor least square optimization model is presented for the decomposition of edge-preserving base layers and *** model not only decomposes the color image(taken as an inseparable indivisibility)in X,Y directions,but also in Z direction,which meets the statistical feature of natural scenes and can physically disclose the intrinsic color *** model’s advantages are twofold:one is the decomposition of edgepreserving base layers and details that can be employed for contrast enhancement without artificial halos,and the other one is the color driving ability that makes the enhanced images as close to natural images as possible via the inherent color ***,the tensor least square optimization model based image enhancement scheme is discussed for the sandstorm weather ***,the experiments and comparisons with the stateof-the-art methods on real degraded images under sandstorm weather are shown to verify our method’s efficiency.

关键词： Image enhancement least square sandstorm weather tensor

Generalized Uncertainty Inequalities on Fisher Information Associated with LCT

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Journal of Beijing Institute of Technology 2021年第3期30卷 217-227页

作者： guanlei xu Xiaogang xu Xiaotong Wang School of Computer and Information Engineering Zhejiang Gongshang UniversityHangzhou 310018China

Uncertainty principle plays an important role in multiple fields such as physics,mathem-atics,signal processing,*** linear canonical transform(LCT)has been used widely in optics and information processing and so *** this paper,a few novel uncertainty inequalities on Fisher information associated with linear canonical transform are *** newly deduced uncer-tainty relations not only introduce new physical interpretation in signal processing,but also build the relations between the uncertainty lower bounds and the LCT transform parameters a,b,c and d for the first time,which give us the new ideas for the analysis and potential *** addi-tion,these new uncertainty inequalities have sharper and tighter bounds which are the generalized versions of the traditional ***,some numeric examples are given to demon-strate the efficiency of these newly deduced uncertainty inequalities.

关键词： linear canonical transform(LCT) Fisher information uncertainty principle

The Properties and Fast Algorithm of Quaternion Linear Canonical Transform

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Journal of Signal and Information Processing 2018年第3期9卷 202-216页

作者： Ye Zhang guanlei xu Nanjing Changjiang Electronics Group Co. Ltd. Nanjing China Dalian Navy Academy Dalian China

The quaternion linear canonical transform (QLCT) is defined in this paper, with proofs given for its reversibility property, its linear property, its odd-even invariant property and additivity property. Meanwhile, the quaternion convolution (QCV), quaternion correlation (QCR) and product theorem of LCT are deduced. Their physical interpretation is given as classical convolution, correlation and product theorem. Moreover, the fast algorithm of QLCT (FQLCT) is obtained, whose calculation complexity for different signals is similar to FFT. In addition, the paper presents the relationship between the convolution and correlation in LCT domains, and the convolution and correlation can be calculated via product theorem in Fourier transform domain using FFT.

关键词： Quaternion Signals (Hyper-Complex Signals) LCT Convolution Correlation

Support-Limited Generalized Uncertainty Relations on Fractional Fourier Transform

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Journal of Signal and Information Processing 2015年第3期6卷 227-237页

作者： Xiaotong Wang guanlei xu Navgation Department of Dalian Naval Academy Dalian China Ocean Department of Dalian Naval Academy Dalian China

This paper investigates the generalized uncertainty principles of fractional Fourier transform (FRFT) for concentrated data in limited supports. The continuous and discrete generalized uncertainty relations, whose bounds are related to FRFT parameters and signal lengths, were derived in theory. These uncertainty principles disclose that the data in FRFT domains may have?much higher concentration than that in traditional time-frequency domains, which will enrich the ensemble of generalized uncertainty principles.

关键词： Discrete Fractional Fourier Transform (DFRFT) Uncertainty Principle Frequency-Limiting Operator

Discrete Inequalities on LCT

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Journal of Signal and Information Processing 2015年第2期6卷 146-152页

作者： guanlei xu Xiaotong Wang Xiaogang xu Ocean Department of Dalian Naval Academy Dalian China Navgation Department of Dalian Naval Academy Dalian China

Linear canonical transform (LCT) is widely used in physical optics, mathematics and information processing. This paper investigates the generalized uncertainty principles, which plays an important role in physics, of LCT for concentrated data in limited supports. The discrete generalized uncertainty relation, whose bounds are related to LCT parameters and data lengths, is derived in theory. The uncertainty principle discloses that the data in LCT domains may have much higher concentration than that in traditional domains.

关键词： Linear Canonical Transform (LCT) Uncertainty Inequality

Amplitude and Phase Analysis Based on Signed Demodulation for AM-FM Signal

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Journal of Computer and Communications 2014年第9期2卷 87-92页

作者： guanlei xu Xiaotong Wang Xiaogang xu Limin Shao Navigation Department Dalian Navy Academy Dalian China Ocean Department Dalian Navy Academy Dalian China

This paper proposes a new amplitude and phase demodulation scheme different from the traditional method for AM-FM signals. The traditional amplitude demodulation assumes that the amplitude should be non-negative, and the phase is obtained under the case of non-negative amplitude, which approximates the true amplitude and phase but distorts the true amplitude and phase in some cases. In this paper we assume that the amplitude is signed (zero, positive or negative), and the phase is obtained under the case of signed amplitude by optimization, as is called signed demodulation. The main merit of the signed demodulation lies in the revelation of senseful physi- cal meaning on phase and frequency. Experiments on the real-world data show the efficiency of the method.

关键词： Amplitude Demodulation Phase Hilbert Transform Signed Demodulation

Time-Varying Bandpass Filter Based on Assisted Signals for AM-FM Signal Separation: A Revisit

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Journal of Signal and Information Processing 2013年第3期4卷 229-242页

作者： guanlei xu Xiaotong Wang Xiaogang xu Lijia Zhou Limin Shao Navgation Department of Dalian Naval Academy Dalian China Ocean Department of Dalian Naval Academy Dalian China

In this paper, a new signal separation method mainly for AM-FM components blended in noises is revisited based on the new derived time-varying bandpass filter (TVBF), which can separate the AM-FM components whose frequencies have overlapped regions in Fourier transform domain and even have crossed points in time-frequency distribution (TFD) so that the proposed TVBF seems like a “soft-cutter” that cuts the frequency domain to snaky slices with rational physical sense. First, the Hilbert transform based decomposition is analyzed for the analysis of nonstationary signals. Based on the above analysis, a hypothesis under a certain condition that AM-FM components can be separated successfully based on Hilbert transform and the assisted signal is developed, which is supported by representative experiments and theoretical performance analyses on a error bound that is shown to be proportional to the product of frequency width and noise variance. The assisted signals are derived from the refined time-frequency distributions via image fusion and least squares optimization. Experiments on man-made and real-life data verify the efficiency of the proposed method and demonstrate the advantages over the other main methods.

关键词： Time-Varying Bandpass Filter (TVBF) Hilbert Tranform Assisted Signal AM-FM Component Time-Frequency Distribution (TFD)

Discrete Entropic Uncertainty Relations Associated with FRFT

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Journal of Signal and Information Processing 2013年第3期4卷 120-124页

作者： guanlei xu Xiaotong Wang Lijia Zhou Limin Shao Xiaogang xu Navgation department of Dalian Naval Academy Dalian China 116018. Ocean department of Dalian Naval Academy Dalian China 116018

Based on the definition and properties of discrete fractional Fourier transform (DFRFT), we introduced the discrete Hausdorff-Young inequality. Furthermore, the discrete Shannon entropic uncertainty relation and discrete Rényi entropic uncertainty relation were explored. Also, the condition of equality via Lagrange optimization was developed, as shows that if the two conjugate variables have constant amplitudes that are the inverse of the square root of numbers of non-zero elements, then the uncertainty relations reach their lowest bounds. In addition, the resolution analysis via the uncertainty is discussed as well.

关键词： Discrete Fractional Fourier Transform (DFRFT) Uncertainty Principle Rényi Entropy Shannon Entropy

Generalized Parseval’s Theorem on Fractional Fourier Transform for Discrete Signals and Filtering of LFM Signals

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Journal of Signal and Information Processing 2013年第3期4卷 274-281页

作者： Xiaotong Wang guanlei xu Yue Ma Lijia Zhou Longtao Wang Automation Department of Dalian Naval Academy Dalian China

This paper investigates the generalized Parseval’s theorem of fractional Fourier transform (FRFT) for concentrated data. Also, in the framework of multiple FRFT domains, Parseval’s theorem reduces to an inequality with lower and upper bounds associated with FRFT parameters, named as generalized Parseval’s theorem by us. These results theoretically provide potential valuable applications in filtering, and examples of filtering for LFM signals in FRFT domains are demonstrated to support the derived conclusions.

关键词： Discrete Fractional Fourier Transform (DFRFT) Uncertainty Principle Frequency-Limiting Operator Linear Frequency-Modulation (LFM) Signal Filtering