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2007 6th International Conference on Information, Communications and signal processing, ICICS

作者： Zhuo, Li Gao, Xuejuan Wang, Zhiyong Feng, David Dagan Shen, Lansun School of IT University of Sydney Sydney NSW Australia Signal and Information Processing Lab. Beijing University of Technology Beijing 100022 China Department of Electronic and Information Engineering HongKong Polytechnic University HongKong Hong Kong

ISBN: (纸本)1424409837

Rate control plays an important role in video coding and transmission. In this paper, instead of using rate-distortion (R-D) model to perform rate control as many existing methods do, a rate-quality (R-Q) model of H.264/AVC has first been proposed to represent the coding characteristics of H.264, where PSNR (Peak signal-to-Noise Ratio) is used to represent the reconstructed video quality. Then a H.264 rate control method at frame layer has been presented based on the proposed R-Q model. In this method, the quantization parameter (i.e. quantization step) of the current frame is determined by the proposed R-Q model according to the coding statistics of the previous coded frames. The experimental results show that, compared with the rate control algorithm of JM86 reference software, the output bit rate achieved by our proposed one is more close to the target bit rate while the reconstructed quality is comparable. ©2007 IEEE.

关键词： Image coding

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An access control model in lager-scale P2P file sharing systems

An access control model in lager-scale P2P file sharing syst...

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7th International Conference on Computational Science (ICCS 2007)

作者： Yue Guang-xue Yu Fei Chen Li-ping Chen Yi-jun College of Information Engineering Jiaxing University 314000 China Department of Computer Science and Technology Huaihua University 418000 China State Key Lab. for Novel Software Technology Nanjing University 210093 China Jiangsu Provincial Key Laboratory of Computer Information Processing Technology Suzhou University 2150063 China

ISBN: (纸本)9783540725893

In lager-scale P2P file sharing systems, peers often must interact with unknown or unfamiliar peers without the benefit of trusted third parties or authorities to mediate the interactions. The decentralized and anonymous characteristics of P2P environments make the task of controlling access to sharing information more difficult. In this paper, we identify access control requirements and propose a trust based access control framework for P2P file-sharing systems. The model integrates aspects of trust and recommendation, fairness based participation schemes and access control schemes.

关键词： Distributed computer systems

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Urban road network extraction from SAR image

Urban road network extraction from SAR image

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MIPPR 2007: Remote Sensing and GIS Data processing and Applications;and Innovative Multispectral technology and Applications

作者： Cheng, Pengxue Hu, Maolin Lab. of Intelligent Computing and Signal Processing Anhui University Hefei Anhui 230039 China Key Laboratory of Wireless Sensor Network and Communication Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China

ISBN: (纸本)9780819469540

In this paper, a technique for the extraction of roads in a high resolution synthetic aperture radar (SAR) image is presented. And a three-step method is developed for the extraction of road network from space borne SAR image: the process of the feature points, road candidate detection and connection. Roads in a high resolution SAR image can be modeled as a homogeneous dark area bounded by two parallel boundaries. Dark areas, which represent the candidate positions for roads, are extracted from the image by a Gaussian probability iteration segmentation. Possible road candidates are further processed using the morphological operators. And the roads are accurately detected by Hough Transform, and the extraction of lines is achieved by searching the peak values in Hough Space. In this process, to detect roads more accurately, post-processing, including noisy dark regions removal and false roads removal is performed. At last, Road candidate connection is carried out hierarchically according to road established models. Finally, the main road network is established from the SAR image successfully. As an example, using the ERS-2SAR image data, automatic detection of main road network in Shanghai Pudong area is presented.

关键词： Feature extraction

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Point matching of two images under large different resolution

Point matching of two images under large different resolutio...

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MIPPR 2007: Automatic Target Recognition and Image Analysis;and Multispectral Image Acquisition

作者： Ruan, Lei Hu, Maolin Lab. of Intelligent Computing and Signal Processing AnHui University Hefei AnHui 230039 China Key Laboratory of Wireless Sensor Network and Communication Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China

ISBN: (纸本)9780819469502

Image matching is the first step in almost any 3D computer vision task, and hence has received extensive attention. In this paper, the problem is addressed from a novel perspective, which is different from the classic stereo matching paradigm. Two images with different resolutions, that is high resolution versus low resolution are matched. Since the high resolution image only corresponds to a small region of the low resolution one, the matching task therefore consists in finding a small region in the low resolution image that can be assigned to the whole high resolution image under the plane similarity transformation, which can be defined by the local area correlation coefficient to match the interest points and rectified by similarity transform. Experiment shows that our matching algorithm can be used for scale changing up to a factor of 6. And it is successful to deal with the point matching between two images under large scale.

关键词： Image matching

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Kautz-Volterra modelling of an analogue-to-digital converter using a stepped three-tone excitation

Kautz-Volterra modelling of an analogue-to-digital converter...

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12th IMEKO TC-4 International Workshop on ADC Modelling and Testing

作者： Björsell, N. Isaksson, M. Händel, P. Rönnow, D. University of Gävle ITB/Electronics SE-801 76 Gävle Sweden Royal Institute of Technology Signal Processing Lab. SE-100 44 Stockholm Sweden WesternGeco AS PB 234 137 Asker Norway

ISBN: (纸本)9789736672644

In many test and measurement applications, the analogue-to-digital converter (ADC) is the limiting component. Using post-correction methods can improve the performance of the component as well as the over all measurement system. In this paper an ADC is characterised by a Kautz-Volterra (KV) model, which utilises a model-based post-correction of the ADC with general properties and a reasonable number of parameters. Results that are based on measurements on a high-speed 12-bit ADC, shows good results for a third order model.

关键词： Analog to digital conversion

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An intelligent fingerprint-biometric image scrambling scheme

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3rd International Conference on Intelligent Computing, ICIC 2007

作者： Khan, Muhammad Khurram Jiashu, Zhang Research Group for Biometrics and Security Engineering Bahria University Dept. of Computer Science and Engineering 13- National Stadium Road Karachi Pakistan Sichuan Key Lab. of Signal and Information Processing Southwest Jiaotong University Chengdu 610031 China

ISBN: (纸本)9783540742012

To obstruct the attacks, and to hamper with the liveness and retransmission issues of biometrics images, we have researched on the challenge/response-based biometrics scrambled image transmission. We proposed an intelligent biometrics sensor, which has computational power to receive challenges from the authentication server and generate response against the challenge with the encrypted biometric image. We utilized the FRT for biometric image encryption and used its scaling factors and random phase mask as the additional secret keys. In addition, we chaotically generated the random phase masks by a chaotic map to further improve the encryption security. Experimental and simulation results have shown that the presented system is secure, robust, and deters the risks of attacks of biometrics image transmission. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Biometrics

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Power spectral density error analysis of spectral subtraction type of speech enhancement methods

Eurasip Journal on Advances in Signal Processing

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Eurasip Journal on Advances in signal processing 2007年 2007卷

作者： Händel, Peter Signal Processing Lab. School of Electrical Engineering Royal Institute of Technology Stockholm SE 100 44 Sweden

A theoretical framework for analysis of speech enhancement algorithms is introduced for performance assessment of spectral subtraction type of methods. The quality of the enhanced speech is related to physical quantities of the speech and noise (such as stationarity time and spectral flatness), as well as to design variables of the noise suppressor. The derived theoretical results are compared with the outcome of subjective listening tests as well as successful design strategies, performed by independent research groups.

关键词： Speech synthesis

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A general evaluation criteria for behavioral power amplifier modeling

A general evaluation criteria for behavioral power amplifier...

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69th ARFTG Microwave Measurements Conference - Addressing Metrology Needs for Future High-Speed Information and Communications Systems

作者： Wisell, David Isaksson, Magnus Keskitalo, Niclas University of Gavle Dept. of Electronics SE-80176 Gavle Sweden Royal Institute of Technology Signal Processing Lab. SE-IOO 44 Stockholm Sweden Ericsson AB SE-16480 Stockholm Sweden Ericsson AB SE-80006 Gävle Sweden

ISBN: (纸本)0780397630

In this paper a new goodness measure for behavioral complex envelope power amplifier models is defined in the frequency domain. The measure can be calculated for any input signal using the same formulas, which makes it general and easy to use. The results will however be dependent on the input signal. The total model error, or normalized mean-square error, for power amplifier models are normally dominated by the in-band error, often mainly caused by the linear distortion. The new measure is aimed at capturing the nonlinear modeling performance of the amplifier model. This is of interest since it is most often the nonlinear, rather than the linear, distortion that causes most harm in real-life power amplifier applications. ©2007 IEEE.

关键词： Power amplifiers

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Spectral and spatial classification of hyperspectral data using SVMs and morphological profiles

Spectral and spatial classification of hyperspectral data us...

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2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007

作者： Fauvel, Mathieu Chanussot, Jocelyn Benediktsson, Jon Atli Sveinsson, Johannes R. GIPSA-LAB. Signal and Image Department Grenoble Institute of Technology - INPG BP 46 38402 St Martin d'Heres France Department of Electrical and Computer Engineering University of Iceland Hjardarhagi 2-6 107 Reykjavik Iceland

ISBN: (纸本)1424412129

Classification of hyperspectral data with high spatial resolution from urban areas is discussed. An approach has been proposed which is based on using several principal components from the hyperspectral data and build morphological profiles. These profiles can be used all together in one extended morphological profile. A shortcoming of the approach is that it is primarily designed for classification of urban structures and it does not fully utilize the spectral information in the data. Similarly, a pixel-wise classification solely based on the spectral content can be performed, but it lacks information on the structure of the features in the image. An extension is proposed in this paper in order to overcome these dual problems. The proposed method is based on the data fusion of the morphological information and the original hyperspectral data: the two vectors of attributes are concatenated. After a reduction of the dimensionality using Decision Boundary Feature Extraction, the final classification is achieved using a Support Vector Machines classifier. The proposed approach is tested in experiments on ROSIS data from urban areas. Significant improvements are achieved in terms of accuracies when compared to results of approaches based on the use of morphological profiles based on PCs only and conventional spectral classification. © 2007 IEEE.

关键词： Support vector machines

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Eccentric error and compensation in rotationally symmetric laser triangulation

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仪器仪表学报 2007年第9期28卷 1548-1553页

作者： Wang Lei Gao Jun Wang Xiaojia Johannes Eckstein Peter Ott Lab of Image Information Processing School of Computer and Information Hefei University of Technology Hefei 230009 China Optical Engineering Lab. Heilbronn University Heilbronn D-74081 Germany Dep. of Mechanical and Electrical Engineering Xiamen University Xiamen 361005 China

Rotationally symmetric triangulation(RST)sensor has more flexibility and less uncertainty limits because of the abaxial rotationally symmetric optical *** if the incident laser is eccentric,the symmetry of the image will descend,and it will result in the eccentric error especially when some part of the imaged ring is *** model of rotationally symmetric triangulation that meets the Schimpflug condition is presented in this *** error from eccentric incident laser is *** is pointed out that the eccentric error is composed of two parts,one is a cosine in circumference and proportional to the eccentric departure factor,and the other is a much smaller quadric factor of the *** the ring is complete,the first error factor is zero because it is integrated in whole ring, but if some part of the ring is blocked,the first factor will be the main *** verifies the result of the a- *** last,a compensation method to the error when some part of the ring is lost is presented based on neural *** results of experiment show that the compensation will make the absolute maximum error descend to half,and the standard deviation of error descends to 1/3.

关键词：补偿作用旋转对称激光三角测量法偏心因子视力测量神经网络

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