检索结果-内蒙古大学图书馆

Experimental parallel implementation of a wavelet-based still image encoder

MICROPROCESSORS AND MICROSYSTEMS 2005年第4期29卷 155-167页

作者： Haapala, K Lappalainen, v Hämäläinen, TD Tampere Univ Technol Inst Digital & Comp Syst FIN-33720 Tampere Finland CSC Sci Comp Ltd FIN-02101 Espoo Finland Nokia Res Ctr FIN-33101 Tampere Finland

A still image encoder implementation is presented for a multi-DSP system called PARNEU, which has previously been developed for neural network and signal processing applications. The core of the implementation is based on experimental mappings of discrete wavelet transform (DWT) on the parallel processor architecture. PARNEU has a flexible interconnection network architecture with message passing, which allows adding more processing units (PUS) to the system whenever more computational power is needed. Program code can be written to adapt to the number of PUs. This is utilized in the presented encoder implementation with emphasis on load balancing among processors as well as on balance between communication and computation. Performance of the implementation is measured with a scaleable number of processors and compared to a sequential reference implementation. Results show that the DWT phase can be efficiently parallelized on PARNEU with 95.6% of its time spent on true parallel computation. The overall speedup with four processors is 2.25, which could be improved by further optimization of an adaptive scanning phase of the encoder. (C) 2004 Elsevier B.v. All rights reserved.

关键词： wavelet transform image coding parallel implementation

来源：评论

学校读者我要写书评

暂无评论

image restoration using statistical wavelet models

Image restoration using statistical wavelet models

引用

conference on wavelets - applications in signal and image processing IX

作者： Liu, J Moulin, P Univ Illinois Beckman Inst Urbana IL 61801 USA

ISBN: (纸本)0819441929

In this paper, we propose an image restoration algorithm based on state-of-the-art wavelet domain statistical models. We present an efficient method to estimate the model parameters from the observations, and solve the restoration problem in orthonormal and translation-invariant (TI) wavelet domains. Substantial improvements over previous wavelet-based restoration methods are obtained. The use of a TI wavelet transform further enhances the restoration performance. We study the improvement from the viewpoint of Bayesian estimation theory and show that replacing an estimator with its TI version will reduce the expected risk if the signal and the degradation model are stationary.

关键词： image restoration overcomplete wavelet representation statistical modeling Bayesian risk

来源：评论

学校读者我要写书评

暂无评论

FPGA implementation of XOR-MUX full adder based DWT for signal processing applications

引用

MICROPROCESSORS AND MICROSYSTEMS 2020年 73卷

作者： Radhakrishnan, P. Themozhi, G. Tagore Engn Coll Dept ECE Chennai Tamil Nadu India AMET Univ Dept EEE Chennai Tamil Nadu India

In the recent past there is a rapid development in the field of digital technology especially in signal processing and image processing based applications Excellent performance high speed, compactable in size low power and less delay are the essential needs of the devices used for applications such as signal processing, audio processing and software define radio and so on. Particularly, digital gadgets are prone to have more critical logic size and power consumption and take large area in vLSI Implementation due to arithmetic operations of adders and multiplier designs. Thus priority architecture of Digital wavelet Transform (DWT) is affected as it comprises a number of Filter banks in level basics, thus all Filter banks have number of adders and multipliers due to coefficient decompositions of low and high pass filters. On this n-size repeated filter logic takes more logic size and power consumption. Here, the proposed work presents a novel approach of DWT by replacing conventional adders and multipliers with XOR-MUX adders and Truncations multipliers thereby reducing the 2n logic size to n-size logic, Finally, the proposed DWT architecture designed in vHDL and also implemented in FPGA XC6SLX9-2TQG144 proved the performance in terms of delay, area and power. (C) 2019 Elsevier B.v. All rights reserved.

关键词： DWT (Discrete wavelet Transform) FPGA(Field Programmable Gate Array)

来源：评论

学校读者我要写书评

暂无评论

ISAR imaging of targets with fast rotating parts using adaptive joint time-frequency processing 5

ISAR imaging of targets with fast rotating parts using adapt...

引用

SPIE conference on wavelet applications v

作者： Wang, Y Ling, H Chen, vC Univ Texas Dept Elect & Comp Engn Austin TX 78712 USA

ISBN: (纸本)081942840X

Based on the adaptive joint time-frequency processing techniques, a new methodology is proposed in this paper to separate the interference due to fast rotating parts from the original ISAR image of the target. The technique entails adaptively searching for the linear chirp bases which best represent the time-frequency behavior of the signal and fully parameterizing the signal with these basis functions. The signal components due to the fast rotating part are considered to be associated with those chirp bases having large displacement and slope parameters, while the signal components due to the target body motion are represented by those chirp bases which have relatively small displacement and slope parameters. By sorting these chirp bases according to their slopes and displacements, the scattering due to the fast rotating part can be separated from that due to the target body. Consequently, the image artifacts overlapping with the original image of the target can be well removed and a clean ISAR image can be produced. Successful applications of the algorithm to numerically simulated and measurement data show the robustness of the algorithm.

关键词： ISAR imaging Doppler smearing fast rotating parts adaptive joint time-frequency processing

来源：评论

学校读者我要写书评

暂无评论

The Application of wavelet Analysis in the signal processing

The Application of Wavelet Analysis in the Signal Processing

引用

International conference on Graphic and image processing (ICGIP)

作者： Li Ruibin Cui Baozhen TaiYuan Univ Technol YangQuan Coll Yangquan Peoples R China North Univ China Sch Mech Engn & Automat Taiyuan Peoples R China

ISBN: (纸本)9780819489326

This paper introduces applications of wavelet analysis in mechanical signal processing based on the therory wavelet analysis and wavelet recognition. It can effectively distinguish different running states of rolling bearing through picking up character of scale-energy. It is one of the important characteristics of signal singularity and irregular mutation that it includes important information. Analysis singularity and the site of singularity using wavelet transform is more effective because wavelet transform has space localization property. In wavelet analysis, the low frequency part of signal represents the development trend of the signal. It corresponds to the maximum scale wavelet coefficients. With the increase of scale, the resolution of time, the development trend of the signal can be more apparent, so wavelet analysis on display the development trend of signal is very useful. Along with the computer hardware technology and specially the DSP technology development, it will provide powerful safeguard for wavelet analysis using project.

关键词： wavelet analysis wavelet recognition signal processing

来源：评论

学校读者我要写书评

暂无评论

wavelet denoising by MSFI and NSFI

Wavelet denoising by MSFI and NSFI

引用

conference on wavelet applications in signal and image processing vIII

作者： Lin, EB Univ Toledo Dept Math Toledo OH 43606 USA

ISBN: (纸本)0819437646

image denoising in wavelet transform domain using thresholding is one of the most effective techniques of image enhancement. Even though the thresholding on the wavelet transform domain generally works well, one can still visually note the remaining noise in the resulting image, especially in the non-edge areas. In this paper, we use Multi-scaling Function Interpolation and Nonseparable Scaling Function Interpolation to smooth the noise image. Several simulation results will be presented and comparisons between MSFI and NSFI methods will be shown.

关键词： wavelet denoising multi-scaling function interpolation nonseparable scaling function interpolation

来源：评论

学校读者我要写书评

暂无评论

Design of Q-shift complex wavelets for image processing using frequency domain energy minimization

Design of Q-shift complex wavelets for image processing usin...

引用

IEEE International conference on image processing

作者： Kingsbury, N Univ Cambridge Dept Engn Signal Proc Grp Cambridge CB2 1PZ England

ISBN: (纸本)0780377508

This paper proposes a new method of designing finite-support wavelet filters, based on minimization of energy in key parts of the frequency domain. In particular this technique is shown to be very effective for designing families of filters that are suitable for use in the shift-invariant DualTree Complex wavelet structure that has been developed by the author recently, and has been shown to be important for a range of image processing applications. The Dual-Tree structure requires most of the wavelet filters to have a well-controlled group delay, equivalent to one quarter of a sample period, in order to achieve optimal shift invariance. The proposed new design technique allows this requirement to be included along with the usual smoothness and perfect reconstruction properties to yield wavelet filters with a unique combination of features: linear phase, tight frame, compact spatial support, good frequency domain selectivity with low sidelobe levels, approximate shift invariance, and good directional selectivity in two or more dimensions.

关键词： image processing

来源：评论

学校读者我要写书评

暂无评论

Seismic imaging in wavelet domain: Decomposition and compression of imaging operator

Seismic imaging in wavelet domain: Decomposition and compres...

引用

conference on wavelet applications in signal and image processing v

作者： Wu, RS Yang, F Univ. of California/Santa Cruz (United States)

ISBN: (纸本)0819425915

We study the decomposition and compression of one-way wave propagation and imaging operators using wavelet transform. We show that the matrix representation of the Kirchhoff imaging operator (Kirchhoff migration operator) in space domain is a dense matrix, while the compressed beamlet-operator matrix which is the wavelet decomposition of the Kirchhoff operator, is a highly sparse matrix. The beamlet imaging operator represents the backpropagation of multiscale orthonormal beams (beamlets) at different positions with different angles. The beamlet-operator behaves differently in different wavelet bases. For sharp and short bases, such as the Daubechies 4 (D4), both the interscale and intrascale coupling are strong. On the other hand, the interscale coupling is relatively weak for smooth bases, such as higher-order Daubechies wavelets, Coiflets, and spline wavelets. The images obtained by the compressed beamlet operators are almost identical to the images from a full-aperture Kirchhoff operator. Compared with the conventional limited-aperture Kirchhoff migration (imaging), beamlet migration (imaging) can retain the wide effective aperture of a full-aperture operator, and hence achieve higher resolution and image quality with reduced computational cost. The compression ratio of the imaging operator ranges from a few times to a few hundred times, depending on the frequency, step length and the wavelet basis.

关键词： wavelets image compression image quality image resolution Space operations Wave propagation wavelet transforms

来源：评论

学校读者我要写书评

暂无评论

Edge-compensated wavelet analysis of irregularly-supported fields

Edge-compensated wavelet analysis of irregularly-supported f...

引用

4th conference on wavelet applications in signal and image processing

作者： Coffey, MA Etter, DM UNIV COLORADO DEPT ELECT & COMP ENGNBOULDERCO 80309

ISBN: (纸本)0819422134

Though wavelets have been used extensively for image coding, compression,and denoising, they are also gaining popularity in the geophysical sciences as an analysis tool. Capitalizing on the wavelet's relatively tight localization in both the time and frequency domains, the wavelet transform of a data field can yield significant information about the localized frequency content of the underlying process. As an analysis technique, though, standard wavelet transforms suffer from some of the real work constraints that data sets often impose. Primary among these is the fact that the data set is not typically supported on a standard rectangular grid. We investigate the application of a boundary-compensated wavelet transform supported on an arbitrarily-shaped region. applications to satellite-based altimetry of ocean basins are presented.

关键词： signal processing wavelet boundary irregular support interval field

来源：评论

学校读者我要写书评

暂无评论

image compression using an edge adapted redundant dictionary and wavelets

引用

signal processing 2006年第3期86卷 444-456页

作者： Peotta, L Granai, L vandergheynst, P Ecole Polytech Fed Lausanne STIITSLTS2 Swiss Fed Inst Technol Signal Proc Inst CH-1015 Lausanne Switzerland

Low bit rate image coding is an important problem regarding applications such as storage on low memory devices or streaming data on the internet. The state of the art in image compression is to use two-dimensional (2-D) wavelets. The advantages of wavelet bases lie in their multiscale nature and in their ability to sparsely represent functions that are piecewise smooth. Their main problem on the other hand, is that in 2-D wavelets are not able to deal with the natural geometry of images, i.e. they cannot sparsely represent objects that are smooth away from regular submanifolds. In this paper we propose an approach based on building a sparse representation of the edge part of images in a redundant geometrically inspired library of functions, followed by suitable coding techniques. Best N-terms non-linear approximations in general dictionaries is, in most cases, a NP-hard problem and sub-optimal approaches have to be followed. In this work we use a greedy strategy, also known as Matching Pursuit to compute the expansion. The residual, that we suppose to be the smooth and texture part, is then coded using wavelets. A rate distortion optimization procedure chooses the number of functions from the redundant dictionary and the wavelet basis. (C) 2005 Published by Elsevier B.v.

关键词： image compression sparse representation greedy approximation matching pursuit wavelet image representation coding redundant dictionaries

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：