检索结果-内蒙古大学图书馆

International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： V. Algazi Signal and Image Processing Laboratory Department Electrical and Computer Engineering University of California Davis USA

This paper describes a technique for the enhancement of images by FIR filters which compensates for the decreased response of human vision at high spatial frequencies. Because many images contain mainly horizontal and vertical features, and because vision is less acute along diagonals, it is possible to design anisotropic enhancement filters which do not increase greatly the background noise. The anisotropic design methodology also incorporates other results on filter design based on human vision which have recently been reported by the author and coworkers.

关键词： Finite impulse response filter Anisotropic filters image enhancement Humans Nonlinear filters Frequency response Additive noise image processing Anisotropic magnetoresistance Visual perception

来源：评论

学校读者我要写书评

暂无评论

A control point theory for boundary representation and matching

A control point theory for boundary representation and match...

引用

International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： D. Paglieroni A. Jain Computer Vision and Image Processing LaboratoryDepartment of Electrical and Computer Engineering University of California Davis CA USA

There are several methods available for representing boundaries in two dimensions. The more widely known ones involve boundary modeling with run-length codes, chain codes and polygons, AR model coefficients, Fourier descriptors (FD's) and B-spline control points (CP's). In this paper, we present results showing the usefulness of CP's in boundary representation. CP's can yield large compression of the boundary data and they exercise local control over boundary shape. Because they can be normalized with respect to scale, translation and rotation, they are valuable in boundary matching applications. Finally, being the series coefficients of spline basis functions, CP's are useful features for boundaries detected in noisy environments.

关键词： Spline Shape control computer vision image processing Laboratories image coding Working environment noise Noise shaping Joining processes computer graphics

来源：评论

学校读者我要写书评

暂无评论

Improved pitch detection algorithm for noisy speech

Improved pitch detection algorithm for noisy speech

引用

International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： Sanguoon Chung V. Algazi Signal and Image Processing Laboratory Department of Electrical and Computer Engineering University of California Davis CA USA

We propose a new, robust pitch detection algorithm for speech degraded by additive noise. Our algorithm exploits the high correlation between adjacent pitch periods that does not exist for the segment as a whole and performs well in the vicinity of voiced/unvoiced regions where the local SNR is low. The algorithm works as follows. We first determine an estimate of the pitch period near the short time peak energy where the local SNR is highest. We then adaptively estimate the local pitch period from the peak towards the transition region by using pitch synchronous cross-correlation with an updated waveform. The performance of this new algorithm is compared to the SIFT and CEPSTRUM algorithms.

关键词： Detection algorithms Speech enhancement Cepstrum Acoustic noise Working environment noise Detectors Cepstral analysis Algorithm design and analysis Time measurement Speech synthesis

来源：评论

学校读者我要写书评

暂无评论

LEARNING CHARACTERISTICS OF STOCHASTIC-GRADIENT-DESCENT ALGORITHMS - A GENERAL STUDY, ANALYSIS, AND CRITIQUE

引用

SIGNAL processing 1984年第2期6卷 113-133页

作者： GARDNER, WA Signal and Image Processing Laboratory Department of Electrical and Computer Engineering University of California Davis 95616 USA

A comprehensive analysis of the mean-square learning characteristics of stochastic-descent algorithms is presented. The approach is based on the commonly exploited simplifying assumption of stationary independent training vectors. Characteristics analyzed include stability, steady-state misadjustment, initial rate of convergence, optimum step size, and steady-state autocovariance and spectral characteristics of the weight-vector. Effects on these characteristics due to degree of randomness of stochastic gradient, particular data distribution, and data corruption are isolated and analyzed. An objective of the work is to keep the number of simplifying assumptions and approximations to a minimum. Comparison of results with previous more approximate analyses are made. Lernkurven von stochastischen Gradienten Algorithmen werden untersucht. Die vereinfachende Annahme von stationären, unabhängigen Trainingsvektoren wird benutzt. Charakteristiken die untersucht werden beinhalten Stabilität, ‘steady state’ Fehlanpassung, Start Konvergenz, optimaler Schritt sowie ‘steady state’ Autokovarianz und spektrale Charakteristik des Gewichtsvektors. Die Effekten auf diese Charakteristiken von dem Zufälligkeitsgrad des stichastischen Gradienten, besonderer Daten Verteilung und Daten Verderbung werden isoliert und analysiert. Ein Zielpunkt dieser Arbeit ist es die Anzahl vereinfachenden Annahmen und Approximationen auf ein minimum zu beschränken. Vergleiche mit Resultaten die von approximativeren Analysen stammen werden gezogen. Une analyse d'ensemble des caractéristiques de convergence de l'erreur quadratique moyenne dans les algorithmes utilisant la décroissance du gradient stochastique est presentée. Cette approche est basée sur l'hypothése simplificatrice classique de stationnarité et indépendance des vecteurs de test. Les caractéristiques analysées comprennent la stabilité, l'écart d'état stable, la vitesse initiale de convergence, le pas optimum d'incrémentation, et l'autocovarian

关键词：

来源：评论

学校读者我要写书评

暂无评论

SEGMENTATION OF A HIGH-RESOLUTION URBAN SCENE USING TEXTURE OPERATORS

引用

computer vision GRAPHICS AND image processing 1984年第3期25卷 273-310页

作者： CONNERS, RW TRIVEDI, MM HARLOW, CA Remote Sensing and Image Processing Laboratory Department of Electrical and Computer Engineering Louisiana State University Baton Rouge Louisiana 70803

A study aimed at segmenting a high-resolution black and white image of Sunnyvale, California, is described. In this study regions were classified as belonging to any one of nine classes: residential, commercial/industrial, mobile home, water, dry land, runway/taxiway, aircraft parking, multilane highway, and vehicle parking. The classes were selected so that they directly relate to the Defense Mapping Agency's Mapping, Charting and Geodesy tangible features. To attack the problem a statistical segmentation procedure was devised. The primitive operators used to drive the segmentation are texture measures derived from cooccurrence matrices. The segmentation procedure considers three kinds of regions at each level of the segmentation: uniform, boundary, and unspecified. At every level the procedure differentiates uniform regions from boundary and unspecified regions. In the assigns a class label to the uniform regions. The boundary and unspecified regions are split to form higher level regions. The methodologies involved are mathematically developed as a series of hypothesis tests. While only a one-level segmentation was performed studies are described which show the capabilities of each of these hypothesis tests. In particular an 83% correct classification was obtained in testing the labeling procedure. These studies indicate that the proposed procedure should be useful for land use classifications as well as other problems.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A PIPELINED RECURSIVE RESIDUE NUMBER SYSTEM DIGITAL-FILTER

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS 1984年第4期31卷 415-417页

作者： SODERSTRAND, MA SINHA, B Signal and Image Processing Laboratory Department of Electrical and Computer Engineering University of California Davis CA USA IBM Corporation Boca Raton FL USA University of California Davis CA USA

The well-known advantages of pipelining as applied to Finite Impulse Response (FIR) Residue Number System (RNS) arithmetic digital filters is extended to the important area of Infinite Impulse Response (IIR) digital filters through a new technique based on augmentation of the IIR transfer function. Through this technique, pipelined IIR filters based on RNS Read-Only-Memory (ROM) table look-up techniques can be designed which offer throughput rates equal to the table look-up time of the ROM's. This high-speed realization can be achieved even though the recursive filter algorithm requires multiple delays in realizing the output of the filter. For the example of a typical second-order IIR filter, the pipelined structure represents a five-fold increase in speed over standard techniques. Higher order realizations will yield proportionately higher speed improvements. Although the new technique does increase somewhat the hardware complexity of the filter, the increase in speed will often justify the additional hardware. The paper discusses the basic technique, stability considerations, and hardware realizations.

关键词： Digital filters IIR filters Finite impulse response filter Hardware Read only memory Pipeline processing Digital arithmetic Transfer functions Throughput Delay

来源：评论

学校读者我要写书评

暂无评论

Identification of unique objects in high resolution aerial images

Identification of unique objects in high resolution aerial i...

引用

Applications of Artificial Intelligence I 1984

作者： Trivedi, Mohan M. Harlow, Charles A. Remote Sensing and Image Processing Laboratory Department of Electrical and Computer Engineering Louisiana State University Baton RougeLA70803 United States

Accurate and reliable detection of unique objects is an important component of an image understanding system. The objects are considered to have a unique pattern and should be recognized based upon their own characteristics. An object detection approach applicable to the high resolution aerial images is developed in the paper. The methodologies incorporate features such as minimal sensitivity to the backgrounds on which objects may appear, ability to detect objects appearing in arbitrary orientations, and use of a unified set of operators to analyze various levels of details. Specifically the gray level cooccurrence matrix is used to provide the early vision operators. Results of several experiments show the promise for the prpposed methods. © 1984 SPIE. All rights reserved.

关键词： Object detection

来源：评论

学校读者我要写书评

暂无评论

Application of a simple hearing model to the design of audio filters

Application of a simple hearing model to the design of audio...

引用

International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： M. Ready V. Algazi Signal and Image Processing Laboratory Department of Electrical and Computer Engineering University of California Davis CA USA

Filtering audio signals with filters designed exclusively from frequency domain specifications may result in an audible distortion in the vicinity of sharp amplitude transitions. This paper considers the application of known psychoacoustical properties to the design of digital audio filters which minimizes this distortion while approximating some ideal frequency domain characteristics. Psychoacoustic properties and a simple model for hearing are reviewed. A weighted least squares design criteria based on the model and frequency domain specifications is given. Examples of FIR and IIR filters are given and compared to classical frequency domain filters.

关键词： Auditory system Finite impulse response filter Frequency domain analysis Psychoacoustic models IIR filters Psychology Filtering Signal design Distortion Digital filters

来源：评论

学校读者我要写书评

暂无评论

Radon transform theory for random fields and optimum image reconstruction from noisy projections

Radon transform theory for random fields and optimum image r...

引用

International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： A. Jain S. Ansari Signal and Image Processing Laboratory Department of Electrical and Computer Engineering University of California Davis CA USA

In this paper we present some new results on Radon transform theory for stationary random fields. In particular we present a new projection theorem which gives the relation between the power spectrum density of one dimensional projections of a stationary random field and its two dimensional power spectrum density. This result yields the optimum mean square reconstruction filter from noisy projections and is useful in other problems such as multidimensional spectral estimation from one dimensional projections, noise analysis in computed tomography, etc. Example are given to demonstrate the usefulness of these results.

关键词： image reconstruction Filters Frequency response Computed tomography Fourier transforms Convolution Stochastic processes Signal processing image processing Laboratories

来源：评论

学校读者我要写书评

暂无评论

Two step color shrinking algorithm for encoding of graphics

Two step color shrinking algorithm for encoding of graphics

引用

International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： P. Kelly V. Algazi Signal and Image Processing Laboratory Department of Electrical and Computer Engineering University of California Davis CA USA

The emphasis of many algorithms that have been proposed for the compression of binary images has been the efficient coding of local redundancy in data. We propose that increased compression may be achieved by a decomposition of the compression problem into two steps. The goal of the first step is to extract the global redundancy in an image. This is achieved by a color shrinking algorithm, The goal of the second step is to code the resulting localized data.

关键词： Encoding image coding Data compression Statistics Source coding computer graphics Signal processing image processing Laboratories Data mining

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：