Article
Computer Science, Information Systems
Zhiyu Lyu, Chengkun Zhang, Min Han
Summary: The proposed DSTnet method combines deep learning and discrete shearlet transform to effectively handle noise at different levels while preserving image details, demonstrating good denoising performance and computational efficiency.
MULTIMEDIA SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
Zhiyu Lyu, Yan Chen, Yimin Hou, Chengkun Zhang
Summary: This paper proposes a novel network called NSTBNet, which integrates nonsubsampled shearlet transform (NSST) and a broad convolutional neural network. It has the ability to handle different noise levels and spatially variant AWGN, achieving a good trade-off between denoising performance and detail preservation.
DIGITAL SIGNAL PROCESSING
(2022)
Article
Environmental Sciences
Xingkun He, Can Wang, Rongyao Zheng, Xiwen Li
Summary: A novel NSST-based GPR image denoising algorithm is proposed in this paper, using grey wolf optimization algorithm to select appropriate parameters, combined with time-varying threshold function and edge protection method, achieving excellent noise removal performance and edge signal protection.
Article
Computer Science, Hardware & Architecture
Yanjun Zhao, Saeid Belkasim, Guillaume Aubry
Summary: Lossy image compression reduces file size by removing redundant information, but traditional wavelet transform methods have high computational complexity. This paper proposes a novel multiresolution region-based image description scheme that is independent of other preprocessing techniques and suitable for parallel processing. Based on this scheme, a compressive and denoising scheme for images is also proposed.
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Engineering, Environmental
M. Tarahi, T. Sabzevari, M. H. Fattahi, T. Derikvand
Summary: Estimation of rainfall-runoff model parameters in ungauged catchments is crucial, and the Nash geomorphological instantaneous unit hydrograph (NGIUH) model is commonly used for this purpose. Different methods, including remote sensing and GIS, have been used to delineate stream networks in catchments based on topographic maps and satellite images. In this study, fractal dimensions of the stream network and main river, as well as the bifurcation ratio, were calculated and new equations proposed to estimate NGIUH parameters. Evaluation in three catchments showed acceptable efficiency coefficients and errors in peak discharge estimation.
STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT
(2022)
Article
Engineering, Electrical & Electronic
Xingkun He, Can Wang, Rongyao Zheng, Zhibin Sun, Xiwen Li
Summary: This paper proposes a novel denoising method using a deep neural network and an improved BM3D algorithm to suppress random noise while preserving effective information in ground penetrating radar (GPR) images. The method achieves excellent denoising performance and is verified through qualitative and quantitative analysis with simulation and field exploration data.
DIGITAL SIGNAL PROCESSING
(2022)
Article
Mathematics, Applied
Santiago Cordova, Daniel Vera
Summary: A new and simple inversion formula for the 2D Radon transform using the shearlet system was proposed in this study. By translating the continuum theory of shearlets to the discrete theory, a computable algorithm was developed to recover digital images from noisy samples while preserving edges. The inversion method based on integral transformations with smooth kernels was shown to outperform the biorthogonal curvelet decomposition (BCD) inversion in numerical simulations.
APPLIED AND COMPUTATIONAL HARMONIC ANALYSIS
(2021)
Review
Computer Science, Information Systems
Tiantian Guo, Tongpo Zhang, Enggee Lim, Miguel Lopez-Benitez, Fei Ma, Limin Yu
Summary: As a mathematical tool, wavelet theory has various applications and is constantly evolving. This article reviews the development history of wavelet theory and focuses on the design and expansion of wavelet transform. It also discusses the advantages of rational wavelet transform and the combination of wavelet theory and neural networks. The article introduces the categories of wavelet-based applications and summarizes the advantages of wavelet analysis in different scenarios. The review clarifies new research challenges and provides guidance for potential wavelet-based applications and new system designs.
Article
Engineering, Electrical & Electronic
Diego F. G. Coelho, Renato J. Cintra, Arjuna Madanayake, Sirani M. Perera
Summary: This paper introduces a collection of scaling methods for generating 2N-point DCT-II approximations based on N-point low-complexity transformations. The proposed techniques outperform the transforms resulting from the JAM scaling method in terms of total error energy and mean squared error, as demonstrated by extensive error analysis based on statistical simulation. Additionally, a hardware implementation shows the competitiveness of the proposed methods compared to the JAM scaling method.
IEEE TRANSACTIONS ON SIGNAL PROCESSING
(2021)
Article
Engineering, Electrical & Electronic
Gopinath Palanisamy, Palanisamy Ponnusamy, Varun P. Gopi
Summary: This paper proposes a suitable preprocessing technique and an accurate method for fovea centre detection in fundus images. By enhancing the luminosity component, improving local contrast, and determining the region of interest, the fovea centre can be accurately located. The proposed method achieves high success rates in various databases.
SIGNAL IMAGE AND VIDEO PROCESSING
(2023)
Article
Computer Science, Software Engineering
P. A. Andrianov
Summary: This paper provides the definition of a periodic discrete multiresolution analysis and characterizes such systems in terms of properties of scaling sequences. It also defines and describes wavelet systems generated by such analyses, along with providing decomposition and reconstruction formulas for the associated discrete wavelet transform.
INTERNATIONAL JOURNAL OF WAVELETS MULTIRESOLUTION AND INFORMATION PROCESSING
(2022)
Review
Physics, Multidisciplinary
Rodrigo Capobianco Guido
Summary: Wavelet-based analyses have made remarkable achievements in physics and related sciences. However, many people still misunderstand the fundamentals of wavelets. This article provides clear explanations of different types of wavelet transforms and their applications, helping readers to effectively utilize wavelets in their research.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Luan Portella, Diego F. G. Coelho, Fabio M. Bayer, Arjuna Madanayake, Renato J. Cintra
Summary: This article presents a variant of transform scaling method to obtain DFT approximations of large blocksize. The proposed method scales up a given transformation successively, leading to different sizes of transformations. The authors fully introduce a 32(4)-point DFT approximation and provide a fast algorithm, arithmetic complexity assessment, and error analysis.
IEEE SIGNAL PROCESSING LETTERS
(2022)
Article
Mathematics
Glenn R. Easley, Kanghui Guo, Demetrio Labate, Basanta R. Pahari
Summary: The study introduces a new multiscale directional representation called cylindrical shearlets and proves its superior approximation properties in dealing with multidimensional data with surface singularities. The N-term approximation obtained by selecting the N largest coefficients of the cylindrical shearlet expansion achieves an optimal decay rate, outperforming other methods such as 3d wavelet and 3d shearlet approximations.
JOURNAL OF GEOMETRIC ANALYSIS
(2021)
Article
Geochemistry & Geophysics
Zhang Ling, Liu Cai, Hu Bin, Zhang ZeQiang, Xu ChenYang, Zeng ZhaoFa, Wang DeLi, Xu Yi
Summary: The use of multi-scale geometric analysis in handling horizontal clutter signal issues in Lunar Penetrating Radar data, successfully onboard Chang'E-3 and Chang'E-4, aids in geological stratification and interpretation studies, revealing the geological stratification and interpretation of the CE-3 landing site.
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
(2021)
