检索结果-内蒙古大学图书馆

Transmission of images over general packet radio services using advanced wavelet image codecs and digital signal processor chips

引用

JOURNAL OF ELECTRONIC IMAGING 2006年第4期15卷

作者： Planinsic, Peter Gleich, Dusan Mohorko, Joze Univ Maribor Fac Elect Engn & Comp Sci Maribor 2000 Slovenia

We develop a wavelet-based codec using a low-cost and low-energy-consuming 16-bit fixed-point digital signal processor (DSP). The target application is designed to grab an image from a camera, code the image using a wavelet-based codec, and send a coded file over a wireless global system for mobile communications/general packet radio services (GSMIGPRS) network. Since the channel capacity of the GSMIGPRS network is limited, a DSP with a relatively low computational power is sufficient to implement an image codec. A trade-off is made between the complexity and the efficiency of the wavelet-based image coder. Any implementation issues concerning the wavelet transform and entropy coding are discussed. Lifting schemes for a 9-7 and a 5-3 filter bank are used. The novel ordering of bit-plane bits is presented. The proposed codec is comparable with a JPEG2000 codec in the rate-distortion sense. The experimental results show that the implementation of JPEG 2000 on the presented platform runs 60% slower than the proposed codec. The coded file is transmitted over a wireless network using Internet protocolluser datagram protocolltrivial file transfer protocol (IP/UDP/TFTP). (c) 2006 SPIE and IS&T.

关键词： Digital signal processing wavelets General packet radio service signal processing image compression Wavelet transforms image processing JPEG2000 Quantization Cameras

来源：评论

学校读者我要写书评

暂无评论

Wavelet-based pavement distress detection and evaluation

引用

OPTICAL ENGINEERING 2006年第2期45卷

作者： Zhou, J Huang, PS Chiang, FP SUNY Stony Brook Dept Mech Engn Stony Brook NY 11794 USA

An automated pavement inspection system consists of image acquisition and distress image processing. The former is accomplished with imaging sensors, such as video cameras and photomultiplier tubes. The latter includes distress detection, isolation, classification, evaluation, segmentation, and compression. We focus on wavelet-based distress detection, isolation, and evaluation. After a pavement image is decomposed into different-frequency subbands by the wavelet transform, distresses are transformed into high-amplitude wavelet coefficients and noise is transformed into low-amplitude wavelet coefficients, both in the high-frequency subbands, referred to as details. Background is transformed into wavelet coefficients in a low-frequency subband, referred to as approximation. First, several statistical criteria are developed for distress detection and isolation, which include the high-amplitude wavelet coefficient percentage (HAWCP), the high-frequency energy percentage (HFEP), and the standard deviation (STD). These criteria are tested on hundreds of pavement images differing by type, severity, and extent of distress. Experimental results demonstrate that the proposed criteria are reliable for distress detection and isolation and that real-time distress detection and screening is currently feasible. A norm for pavement distress quantification, which is defined as the product of HAWCP and HFEP, is also proposed. Experimental results show that the norm is a useful index for pavement distress evaluation. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

关键词： wavelet transform automated pavement inspection pavement distress image processing distress detection and isolation distress evaluation

来源：评论

学校读者我要写书评

暂无评论

Adaptive blind wavelet-based watermarking technique using tree mutual differences

引用

JOURNAL OF ELECTRONIC IMAGING 2006年第4期15卷

作者： Al-Otum, Hazem Munawer Samara, Nedal Abdul Jordan Univ Sci & Technol Dept Elect Engn Irbid 22110 Jordan

An adaptive blind wavelet-based watermarking scheme using tree mutual differences (ABW-TMD) is proposed by exploiting mutual differences between grouped coefficients of so-called wavelet trees. The ABW-TMD encoder adaptively searches for the bit host difference in such a manner to minimize the embedding error The proposed ABW-TMD scheme proves its superiority in resisting against various image processing attacks as well as in reducing the computational cost when compared to other schemes. For the same watermark bit length, a 35% increase in peak signal-to-noise ratio (PSNR) can be achieved over what is possible using an earlier method. Also, when fixing the PSNR of the watermarked image, the watermark bit length can be doubled with the ability to extract the watermark, even in the presence of high JPEG/JPEG2000 compression ratios. (c) 2006 SPIE and IS&T.

关键词： Digital watermarking image compression wavelets image quality Digital filtering Gaussian filters Computer programming Electronic filtering Filtering (signal processing) image filtering

来源：评论

学校读者我要写书评

暂无评论

Multiscale hybrid linear models for lossy image representation

引用

IEEE TRANSACTIONS ON image processing 2006年第12期15卷 3655-3671页

作者： Hong, Wei Wright, John Huang, Kun Ma, Yi Texas Instruments Inc DSP Solut Res & Dev Ctr Dallas TX 75243 USA Univ Illinois Dept Elect & Comp Engn Urbana IL 61801 USA Ohio State Univ Dept Biomed Informat Columbus OH 43210 USA

In this paper, we introduce a simple and efficient representation for natural images. We view an image (in either the spatial domain or the wavelet domain) as a collection of vectors in a high-dimensional space. We then fit a piece-wise linear model (i.e., a union of affine subspaces) to the vectors at each downisampling scale. We call this a multiscale hybrid linear model for the image. The model can be effectively estimated via a new algebraic method known as generalized principal component analysis (GPCA). The hybrid and hierarchical structure of this model allows us to effectively extract and exploit multimodal correlations among the imagery data at different scales. It conceptually and computationally remedies limitations of many existing image representation methods that are based on either a fixed linear transformation (e.g., DCT, wavelets), or an adaptive uni-modal linear transformation (e.g., PCA), or a multimodal model that uses only cluster means (e.g., VQ). We will justify both quantitatively and experimentally why and how such a simple multiscale hybrid model is able to reduce simultaneously the model complexity and computational cost. Despite a small overhead of the model, our careful and extensive experimental results show that this new model gives more compact representations for a wide variety of natural images under a wide range of signal-to-noise ratios than many existing methods, including wavelets. We also briefly address how the same (hybrid linear) modeling paradigm can be extended to be potentially useful for other applications, such as image segmentation.

关键词： generalized principal component analysis hybrid linear model image representation wavelets

来源：评论

学校读者我要写书评

暂无评论

On interpolation and resampling of discrete data

引用

IEEE signal processing LETTERS 2006年第12期13卷 733-736页

作者： Tafti, Pouya Dehghani Shirani, Shahram Wu, xiaolin McMaster Univ Dept Elect & Comp Engn Hamilton ON L8S 4K1 Canada

This letter introduces a new representation of discrete signals based on the mathematical notions of functionals and continuous dual spaces. A new and more general sampling theorem is also suggested. Next, the problems of interpolating and resampling discrete signals are addressed;and a general solution using functional interpolation-which is applicable to many different settings-is proposed. Families of resampling filters dubbed de Boor-Ron filters that use de Boor-Ron interpolation are introduced, and their numerical realization is discussed. Some applications of this research are suggested.

关键词： de Boor-Ron filters image interpolation multiresolution multivariate interpolation resampling sampling theorem super-resolution wavelets

来源：评论

学校读者我要写书评

暂无评论

An efficient illumination normalization method for face recognition

引用

PATTERN RECOGNITION LETTERS 2006年第6期27卷 609-617页

作者： xie, xD Lam, KM Hong Kong Polytech Univ Dept Elect & Informat Engn Ctr Multimedia Signal Proc Kowloon Hong Kong Peoples R China

In this paper, an efficient representation method insensitive to varying illumination is proposed for human face recognition. Theoretical analysis based on the human face model and the illumination model shows that the effects of varying lighting on a human face image can be modeled by a sequence of multiplicative and additive noises. Instead of computing these noises, which is very difficult for real applications, we aim to reduce or even remove their effect. In our method, a local normalization technique is applied to an image, which can effectively and efficiently eliminate the effect of uneven illuminations while keeping the local statistical properties of the processed image the same as in the corresponding image under normal lighting condition. After processing, the image under varying illumination will have similar pixel values to the corresponding image that is under normal lighting condition. Then, the processed images are used for face recognition. The proposed algorithm has been evaluated based on the Yale database, the AR database, the PIE database, the YaleB database and the combined database by using different face recognition methods such as PCA, ICA and Gabor wavelets. Consistent and promising results were obtained, which show that our method can effectively eliminate the effect of uneven illumination and greatly improve the recognition results. (c) 2005 Elsevier B.V. All rights reserved.

关键词： face recognition illumination compensation local normalization method principal component analysis(PCA) independent component analysis (ICA) Gabor wavelets

来源：评论

学校读者我要写书评

暂无评论

Accelerating rotation of high-resolution images

引用

IEE PROCEEDINGS-VISION image AND signal processing 2006年第6期153卷 815-824页

作者： Suchitra, S. Lam, S. K. Clarke, C. T. Srikanthan, T. Nanyang Technol Univ Ctr High Performance Embedded Syst Singapore 637553 Singapore Univ Bath Dept Elect & Elect Engn Bath BA2 7AY Avon England

Real-time image rotation is an essential operation in many application areas such as image processing, computer graphics and pattern recognition. Existing architectures that rely on CORDIC computations for trigonometric operations cause a severe bottleneck in high-throughput applications, especially where high-resolution images are involved. A novel hierarchical method that exploits the symmetrical characteristics of the image to accelerate the rotation of high-resolution images is presented. Investigations based on a 512 x 512 image show that the proposed method yields a speedup of similar to 20x for a mere 3% increase in area cost when compared with existing techniques. Moreover, the effect of hierarchy on the computational efficiency has been evaluated to provide for area-time flexibility. The proposed technique is highly scalable and significant performance gains are evident for very high-resolution images.

关键词： CORDIC Digital arithmetic methods Optical, image and video signal processing image processing computer graphics image resolution pattern recognition high-resolution images digital arithmetic Computer vision and image processing techniques real-time image rotation

来源：评论

学校读者我要写书评

暂无评论

applications of non-orthogonal filter banks to signal and image analysis

Applications of non-orthogonal filter banks to signal and im...

引用

IEEE/PES Transmission and Distribution Conference and Exposition Latin America

作者： Soares, Luciana R. de Oliveira, H. M. Cintra, Renato J. S. Univ Fed Pernambuco Dept Elect & Syst Signal Proc Grp CP 7800 BR-50711970 Recife PE Brazil Univ Fed Pernambuco Dept Stat Recife PE Brazil

ISBN: (纸本)9781424402878

A non-orthogonal wavel ET-based multiresolution analysis was already provided by scaling and wavelet filters derived from Gegenbauer polynomials. Allowing for odd n (the polynomial order) and a value (a polynomial parameter) within the orthogonality range of such polynomials, scaling and wavelet functions are generated by frequency selective FIR filters. These filters have compact support and generalized linear phase. Special cases of such filter banks include Haar, Legendre, and Chebyshev wavelets. As an improvement, it has been achieved that for specific a values it is possible to reach a filter with flat magnitude frequency response. We obtain a unique closed expression for a value for every n odd value. The main advantages in favor of Gegenbauer filters are their smaller computational effort and a constant group delay, as they are symmetric filters. Potential applications of such wavelets include fault analysis in transmission lines of power systems and image processing.

关键词： chebyshev wavelets discrete-time filters filter banks Gegenbauer polynomials Gegenbauer wavelets image analysis legendre wavelets multiresolution analysis signal analysis wavelet transform

来源：评论

学校读者我要写书评

暂无评论

A Fourier-radial descriptor algorithm for invariant feature extraction

引用

INTERNATIONAL JOURNAL OF wavelets MULTIRESOLUTION AND INFORMATION processing 2006年第1期4卷 197-212页

作者： Sastry, CS Pujari, AK Deekshatulu, BL Univ Hyderabad Dept Comp & Informat Sci Hyderabad 500046 Andhra Pradesh India

By integrating the Fourier techniques and the edge information obtained using the radial symmetric functions, we propose in this paper an invariant feature extraction algorithm. Unlike the Gabor feature extraction method, the present method does not use direction dependent filters, nor does it use the images in polar form, for rotation invariance. Besides, the present Fourier-Radial invariant feature extraction algorithm, suitable for both the texture and non-texture images, has functional analogy with the Gabor feature extraction method, and hence, is easily implementable. It is mathematically proved, and justified through computations, that the method can generate the invariant and discriminative feature vectors. Our simulation results demonstrate that the method can be used for such applications as content-based image retrieval.

关键词： invariant feature extraction content based image retrieval radially symmetric function

来源：评论

学校读者我要写书评

暂无评论

ISITRA: A generalized way of signal decomposition and reconstruction

引用

DIGITAL signal processing 2006年第1期16卷 3-23页

作者： Singh, YK Parui, SK Indian Stat Inst Comp Vis & Pattern Recognit Unit Kolkata 700108 W Bengal India

A new generalized way of signal decomposition and reconstruction entitled ISITRA is proposed. It is similar to the 2-channel filter bank scheme. fit ISITRA, all the filters are obtained from a real vector. ISITRA allows decomposition of a signal into (1) an approximation and a detail, (2) two details and (3) two approximations. The latter two cases are not generally possible in the filter bank scheme. The choice of filter coefficients in ISITRA is much simpler and more arbitrary compared to that in the existing schemes. This allows one to find better filter coefficients for different applications. One can straight achieve an image compression ratio of 8:1 without doing any coding by modifying the range of pixel values in the decomposed components. One can also find a better set of decomposition and reconstruction filters than the commonly used Daubechies' wavelet filters of length 4. ISITRA is simpler and computationally marginally better than even the computationally efficient polyphase filter bank scheme. (c) 2005 Elsevier Inc. All rights reserved.

关键词： signal decomposition perfect reconstruction polyphase scheme convolution filter banks wavelets multi-resolution analysis compression

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：