检索结果-内蒙古大学图书馆

Online blind equalisation algorithm of an FIR MIMO channel system for non-stationary signals

IEE PROCEEDINGS-VISION image AND signal processing 2005年第5期152卷 575-581页

作者： Shen, x Shi, x Shanghai Jiao Tong Univ Natl Key Lab Vibrat Shock & Noise Shanghai 200030 Peoples R China Shanghai Inst Technol Sch Mech & Automat Engn Shanghai 200235 Peoples R China

Blind equalisation of an FIR multi-input multi-output channel system is an important task for numerous applications such as speech separation, de-reverberation, communication, signal processing and control, etc. In this paper, a cost function with the knowledge of correlation is reconstructed and a new online algorithm derived with a natural gradient search method for blind source separation of convolutional mixtures. Its implementation is simple and practical. Furthermore, the equivariance property is possessed by the algorithm. Simulations indicate the ability of the algorithm to perform blind equalisation under the weaker condition (the FIR system is equalisable) and also to make speech separation and de-reverberation simultaneous.

关键词： ALGORITHMS signal processing SPEECH INFORMATION measurement signal theory (Telecommunication) ONLINE algorithms

来源：评论

学校读者我要写书评

暂无评论

A review on time-frequency, time-scale and scale-frequency domain signal analysis

引用

IETE JOURNAL OF RESEARCH 2005年第4期51卷 287-293页

作者： Samantaray, L Dash, M Panda, R Univ Coll Engn Dept Elect & Telecommun Engn Burla 768018 India

This paper presents a review on Time-frequency, Time-scale and Scale-frequency domain signal analysis. The distinctive features of these techniques are discussed with respect to the decomposition of a signal at different resolutions. The concept of "Time-frequency", "Time-scale" and "Scale-frequency" analysis of a signal has been explained. Some examples are presented to reveal the suitability of these techniques. The main thrust is to focus the use of these techniques for different digital signal and image processing applications.

关键词： signal processing multiresolution analysis wavelet transform spine transform image processing

来源：评论

学校读者我要写书评

暂无评论

Multiresolution direction filterbanks: Theory, design, and applications

引用

IEEE TRANSACTIONS ON signal processing 2005年第10期53卷 3895-3905页

作者： Nguyen, TT Oraintara, S Univ Texas Dept Elect Engn Arlington TX 76011 USA

This paper presents new,developments of directional filterbanks (DFBs). The motivation for the paper is the existence of multiresolution and multidirection orthogonal transform for two-dimensional (2-D) discrete signals. Based on the frequency supports of the ideal transform, a new uniformly, maximally decimated DFB with six highpass directional subbands and two lowpass subands is introduced. The uniform DFB (uDFB) can be implemented by a binary tree structure of two-channel filterbanks. The filterbank employed in the tree is shown to be alias-free decimation and permissible. The uDFB is then extended to a nonuniform case (nuDFB), which is still maximally decimated, by combining the two lowpass subbands. The nuDFB yields nonuniform frequency division, which composes of one lowpass filter with a decimation factor of one fourth and six highpass directional filters with a decimation factor of one eighth. The new DFBs offer alternative image decompositions, which overcome the limited directional selectivity of the separable wavelets and the limited multiresolution of the conventional DFB. The lowpass subband of the nuDFB can be used to obtain a multiresolution representation by simply reiterating the same nuDFB decomposition. On the other hand, the directional subbands can also be further refined by simply applying a two-channel conventional DFB at each highpass component. A simple design method yielding near orthogonal uniform and nonuniform multidimensional filterbanks is presented. Finally, the performances of the newly proposed nuDFB are compared with other conventional transforms in nonlinear approximation, image denoising, and texture classification to demonstrate its potential.

关键词： curvelet transform directional decomposition directional filterbank directional information image decomposition multiresolution permissibility texture classification two-dimensional digital filters two-dimensional filterbanks two-dimensional filter design

来源：评论

学校读者我要写书评

暂无评论

Robust spatial watermarking technique for colour images via direct saturation adjustment

引用

IEE PROCEEDINGS-VISION image AND signal processing 2005年第5期152卷 561-574页

作者： Huang, PS Chiang, CS Chang, CP Tu, TM Natl Def Univ Chung Cheng Inst Technol Dept Elect Engn Toda Saitama 335 Japan

Most colour watermarking methods are realised by modifying the image luminance or by processing each component of colour space separately. This paper presents a novel and robust colour watermarking approach for applications in copy protection and digital archives. The proposed scheme considers chrominance information that can be utilised at information embedding. This work presents an approach for hiding the watermark into DC components of the colour image directly in the spatial domain, followed by a saturation adjustment technique performed in RGB space. The merit of the proposed approach is that it not only provides promising watermarking performance but also is computationally efficient. Experimental results demonstrate that this scheme successfully makes the watermark perceptually invisible and robust to image processing operations such as general image processing operations (JPEG2000, JPEG-loss compression, lowpass filtering, and medium filtering), image scaling and image cropping.

关键词： image processing WATERMARKS COLOR IDENTIFICATION MARKS of origin JPEG (image coding standard)

来源：评论

学校读者我要写书评

暂无评论

Projective rectification based on relative modification and size extension for stereo image pairs

引用

IEE PROCEEDINGS-VISION image AND signal processing 2005年第5期152卷 623-633页

作者： Wu, HHP Yu, YH Chen, WC Natl Yunnan Univ Sci & Technol Grad Sch Engn Sci & Technol Touliu Taiwan

For stereo vision applications, projective geometry has proved to be a useful tool for solving the rectification problem without camera calibration. However, the criterion of minimisation for projective rectification must be chosen properly in order to avoid unduly geometric distortion. In this paper, an improved algorithm to minimise the distortion by combining a newly developed projective transform with a properly chosen shearing transform is proposed. The emphasis on low geometric distortion makes this method not only appropriate for 3-D reconstruction but also for stereoscopic viewing applications. On the basis of relative modification, this new method contains fewer parameters (6 degrees of freedom) for minimisation, which reduces the processing time, and improves the rectification result. Several different types of image pairs were tested to demonstrate the applicability and reliability of the proposed algorithm visually and quantitatively. Comparisons with other methods are also provided to verify the improvement of this new scheme.

关键词： ALGORITHMS PROJECTIVE geometry image processing CAMERAS MODERN geometry CALIBRATION PHYSICAL measurements

来源：评论

学校读者我要写书评

暂无评论

Run-time reconfigurable systems for digital signal processing applications: A survey

引用

Journal of VLSI signal processing Systems for signal, image, and Video Technology 2005年第3期39卷 213-235页

作者： Shoa, Alireza Shirani, Shahram Dept. of Elec. and Computer Eng. McMaster University Hamilton Canada

Today's digital signal processing (DSP) applications use computationally complex and/or adaptive algorithms and have stringent requirements in terms of speed size cost power consumption and throughput. Efficient hardware implementation techniques should be employed to meet the requirements of these applications. Run-Time Reconfiguration (RTR) is a promising technique for reducing the hardware required for implementing DSP systems as well as improving the performance speed and power consumption of these systems. In this survey we explain different issues in run-time reconfigurable systems and list the implemented systems which support run-time reconfiguration. We also describe different applications of run-time reconfiguration and discuss the improvements achieved by applying run-time reconfiguration. © 2005 Springer Science + Business Media Inc.

关键词： Digital signal processing

来源：评论

学校读者我要写书评

暂无评论

Non-separable 2D biorthogonal wavelets with two-row filters

引用

INTERNATIONAL JOURNAL OF wavelets MULTIRESOLUTION AND INFORMATION processing 2005年第1期3卷 1-18页

作者： Zhan, YW Heijmans, HJAM Guangdong Univ Technol Fac Comp Sci Guangzhou 510090 Peoples R China Ctr Math & Comp Sci NL-1090 GB Amsterdam Netherlands CWI NL-1009 AB Amsterdam Netherlands

In the literature 2D (or bivariate) wavelets are usually constructed as a tensor product of ID wavelets. Such wavelets are called separable. However, there are various applications, e.g. in image processing, for which non-sepaxable 2D wavelets are prefered. In this paper, we investigate the class of compactly supported orthonormal 2D wavelets that was introduced by Belogay and Wang.(2) A characteristic feature of this class of wavelets is that the support of the corresponding filter comprises only two rows. We axe concerned with the biorthogonal extension of this kind of wavelets. It turns out that the 2D wavelets in this class are intimately related to some underlying ID wavelet. We explore this relation in detail, and we explain how the 2D wavelet transforms can be realized by means of a lifting scheme, thus allowing an efficient implementation. We also describe an easy way to construct wavelets with more rows and shorter columns.

关键词： perfect reconstruction filter bank non-separable 2D wavelets lifting scheme accuracy biorthogonality subband scheme Laurent polynomial

来源：评论

学校读者我要写书评

暂无评论

Construction and application of hybrid wavelet and other parametric orthogonal transforms

引用

JOURNAL OF MATHEMATICAL IMAGING AND VISION 2005年第1期23卷 25-46页

作者： Sarukhanyan, H Petrosian, A Natl Armenian Acad Sci Inst Informat & Automat Problems Yerevan Armenia Texas Tech Univ Lubbock TX 79409 USA

We introduce new methods for construction and implementation of various parametric and hybrid orthogonal transforms, including generalized Haar-like, Daubechies, and Coiflet wavelet transforms. The corresponding fast algorithms of computations are briefly discussed and the variance properties of these transforms in analyzing 1-st order Markov processes are investigated. The designed hybrid transforms can be useful in various specific signal processing applications where combining properties of Hadamard and wavelet transforms may be of particular benefit. We also present some numerical results pertaining to image zonal and threshold coding using these hybrid transforms and compare their efficacy with those of traditional orthogonal transforms.

关键词： wavelets parametric and hybrid orthogonal transforms generalized Haar-like Daubechies, and Coiflet wavelet transforms Hadamard matrices image compression

来源：评论

学校读者我要写书评

暂无评论

Sci-Fri AM General-08: image Fusion for Catheter Tracking in MR-Guided Endovascular Therapy

引用

Medical Physics 2006年第7PART3期33卷 2669-2669页

作者： JN Draper M Sabati ML Lauzon R Frayne University of Calgary Calgary Alberta Seaman Family MR Research Centre Foothills Medical Centre Calgary Health Region Calgary Alberta

Endovascular therapy describes a class of minimally invasive treatments for certain vascular diseases, including the placement of stents to correct arterial stenoses, and the administration of intra-arterial thrombolysis for ischemic stroke. Our objective is to develop a real-time system to guide interventional endovascular procedures with MR imaging. Our approach in developing this system is to mimic, where appropriate and possible, the functionality of current clinical x-ray fluoroscopy systems. Our endovascular MR system is comprised of two major components: a data acquisition module and an image reconstruction module. Data acquisition was performed using a 3-tesla MR scanner (Signa VH/i; General Electric Healthcare; Waukesha, WI). image reconstruction was performed on a separate dedicated workstation (2.2-GHz Athlon processor-equipped workstation running Windows xP). We achieved catheter visualization by filling catheters with MR contrast and imaging using a multi-cycle projection dephaser to suppress the background signal. We used image-processing filters available in the VTK library to isolate the catheter in the background-suppressed images. The output of this image-filtering pipeline was then used as a mask for an anatomical roadmap image. The image fusion process described herein has successfully been used to combine background-suppressed in vivo images of a catheter with anatomical roadmap images. The fusion process removed most of the noise and residual background signal from the background-suppressed image, leaving the catheter with improved conspicuity. Our endovascular MR system functions in a similar manner to x-ray fluoroscopic systems and has applications in the treatment of stroke and other vascular diseases.

关键词： Medical imaging Medical image reconstruction Data acquisition Medical magnetic resonance imaging Pipelines Electric currents Visualization Fluoroscopy Medical image contrast image scanners

来源：评论

学校读者我要写书评

暂无评论

Low-bit-rate color image encoder using an adaptive morphological pyramid decomposition

引用

JOURNAL OF ELECTRONIC IMAGING 2005年第3期14卷 033014.1-033014.1页

作者： Al-Otum, HAM Ibbini, MS Jordan Univ Sci & Technol EE Dept Irbid 22110 Jordan

Interest in multiresolution techniques for image processing and coding is increasing steadily. An attractive instance is pyramid decomposition schemes due to their low computational complexity, simple parallel implementation, and ability to produce acceptable color images at moderate data rates. We present an approach combining a modified pyramidal algorithm and mathematical morphology for color image coding applications denoted as the adaptive morphological pyramid coding (AMPC) algorithm. The proposed AMPC pyramidal strategy involves (1) building a multilevel pyramid based on a developed adaptive morphological filter that preserves the significant details (without shape bias) and does not require very high computational cost, and then (2) the resulting pyramid levels (images) are applied to suitable coding techniques including an adaptive 3-D vector quantization (AVQ). The proposed technique gives an average peak SNR (PSNP) in the range 46.78 to 50.7 dB when no additional coding is applied. When AVQ and differential pulse code modulation (DPCM) are applied to the pyramid levels an average PSNP varies in the range 22.2 to 37.8 dB) at bit rates in the range 0.07 to 1.51 bpp is obtained. When compared with JPEG/JPEG2000, embedded zero-tree wavelet (EZW) coding and set partition in hierarchical trees (SPIHT), the proposed algorithm provides comparable reconstruction quality. (c) 2005 SPIE and IS&T.

关键词： image compression image filtering Computer programming RGB color model image transmission image quality Adaptive optics image processing Digital filtering wavelets

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：