检索结果-内蒙古大学图书馆

IEEE International Conference on image processing

作者： Kai Guo Xiaokang Yang Rui Zhang Songyu Yu Hongyuan Zha Institute of Image Communication and Information Processing Shanghai Key Laboratory of Digital Media Processing and Transmission Shanghai Jiaotong University Shanghai China College of Computing Georgia Institute of Technology Atlanta GA USA

Traditional image interpolation methods assume that the local spatial structure of the low-resolution (LR) and high-resolution (HR) images are approximately the same, and use edge information of the LR image to estimate the missing pixels. This assumption, however, no longer holds for natural images with fine and dense textures. Consequently, those methods cannot restore dense textures well and tend to generate over-fitting visual effects. In this paper, a learned HR image prior is exploited to overcome the problems. In particular, we use Fields of Experts (FoE) with student's t-distribution experts to model the prior, taking advantage of its representative ability of non-Gaussian natures in images. Then Maximum a Posterior (MAP) estimation incorporating FoE prior is used to estimate the missing pixels. Experimental results compared with traditional interpolation methods demonstrate that our method not only can recover fine details and produce superior PSNR values, but also avoid the visual over-fitting problems.

关键词： Interpolation Pixel image restoration Visual effects PSNR Layout image resolution image communication Information processing Biometrics

来源：评论

学校读者我要写书评

暂无评论

Improved frame-layer bit allocation scheme for H.264/AVC rate control

引用

Journal of Shanghai Jiaotong University (Science) 2009年第2期14 E卷 143-148页

作者： Lin, Gui-Xu Zheng, Shi-Bao Zhu, Liang-Jia Institute of Image Communication and Information Processing Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200240 China Shanghai Key Laboratory of Digital Media Processing and Transmissions Shanghai Jiaotong University Shanghai 200240 China Department of Automatic Control National University of Defense Technology Changsha 410073 China

In this paper, we aim at improving the video quality degradation due to high motions or scene changes. An improved frame-layer bit allocation scheme for H.264/AVC rate control is proposed. First, current frame is pre-encoded in 16 × 16 modes with a fixed quantization parameter (QP). The frame coding complexity is then measured based on the resulting bits and peak signal-to-ratio (PSNR) in the pre-coding stage. Finally, a bit budget is calculated for current frame according to its coding complexity and inter-frame PSNR fluctuation, combined with the buffer status. Simulation results show that, in comparison with the H.264 adopted rate control scheme, our method is more efficient to suppress the sharp PSNR drops caused by high motions and scene changes. The visual quality variations in a sequence are also relieved. Copyright.

关键词： Budget control

来源：评论

学校读者我要写书评

暂无评论

Optimal approximation of head-related transfor function based on adaptive genetic algorithm

Optimal approximation of head-related transfor function base...

引用

2008 IEEE International Conference Neural Networks and Signal processing, ICNNSP

作者： Xuelong, Hu Yan, Tang Jun, Cai School of Information Engineering Yangzhou University Yangzhou Jiangsu 225009 China Jiangsu Province Key Lab. for Image Processing and Image Communication Nanjing University of Posts and Communications Nanjing Jiangsu 210003 China

ISBN: (纸本)9781424423118

Head-related Transfer Functions (HRTFs) refer to the spectral filtering from sound sources to listeners' eardrums or ear canals. As an effective model structure, the degree of the IIR filter approximation of the HRTFs, whose design and implementation is a specific spectrum function approximation process, is much lower than that of the FIR. Based on the assessment of HRTFs different importance for sound sources recognition in different spectrum bands, and associated with some perspectives of psychoacoustics in spatial hearing, adaptive and revalued coding genetic algorithm (GA) is applied to the approximation of the HRTFs zero-pole model. The results show that, on an average, the performance of adaptive GA is better than that of the traditional GA. ©2008 IEEE.

关键词： Transfer functions

来源：评论

学校读者我要写书评

暂无评论

Mixed image de-noising method of Bayesian estimation and wavelet based on alpha-stable distribution

Mixed image de-noising method of Bayesian estimation and wav...

引用

2008 IEEE International Conference Neural Networks and Signal processing, ICNNSP

作者： Zhijian, Wang Xuelong, Hu Cheng, Li Liping, Wang School of Information Engineering Yangzhou University Yangzhou Jiangsu 225009 China Jiangsu Province Key Lab. for Image Processing and Image Communication Nanjing University of Posts and Communications Nanjing Jiangsu 210003 China Yangzhou Jiangsu 225001 China

ISBN: (纸本)9781424423118

This paper introduces a new kind of recovery method which is the combination of Bayesian estimation and wavelet threshold. Wavelet coefficients of signals show strong characteristics of the non-Gauss statistics, its probability density function can be modeled by alpha-stable priori distribution. This paper uses Bayesian estimation to obtain the low frequency coefficients, and deals with high frequency coefficients with the wavelet soft threshold, then restore signal by wavelet inverse transform. Bayesian estimation well retains the marginal information of signals, but the signal is still not very smooth recovery and wavelet soft threshold can maintain smooth characteristic. The mixed noise elimination methods of Bayesian estimation and wavelet enhance the peak SNR much greater than wavelet threshold, which has better recovery effect. ©2008 IEEE.

关键词： Probability density function

来源：评论

学校读者我要写书评

暂无评论

Approaches to image retrieval using fuzzy set theory

Approaches to image retrieval using fuzzy set theory

引用

2008 IEEE International Conference Neural Networks and Signal processing, ICNNSP

作者： Li, Yang Xuelong, Hu Jun, Pan School of Information Engineering Yangzhou University Yangzhou Jiangsu 225009 China Jiangsu Province Key Lab. for Image Processing and Image Communication Nanjing University of Posts and Communications Nanjing Jiangsu 210003 China Jiangsu Prov. Key Lab. for Computer Information Processing Technology Suzhou University Suzhou Jiangsu 215006 China

ISBN: (纸本)9781424423118

This paper mainly presents two approaches for image retrieval. There is some faintness in color locating in quantification boundary when image color is quantized. The membership function in fuzzy set theory can describe the fuzzy transition preferably. In this paper, the membership function in HSI color space is adopted to solve the problem above. At the same time, spatial information is integrated with color feature to describe the image content more truly. Due to the importance of texture feature, gray concurrence matrix is extracted. In the second part of this paper, retrieval scheme combining four image feature descriptors is presented, and then follows Fuzzy Hamming Distance (FHD) which is used as a fuzzy similarity measure. We have performed an experiment on a 1000 images database and our results show higher retrieval accuracy. © 2008 IEEE.

关键词： Fuzzy sets

来源：评论

学校读者我要写书评

暂无评论

A novel ant colony based cross-layer QoS routing algorithm for wireless mesh networks

A novel ant colony based cross-layer QoS routing algorithm f...

引用

2008 11th IEEE International Conference on communication Technology, ICCT 2008

作者： Hui, Zhang Yu-Ning, Dong Long-Xiang, Yang Hong-Bo, Zhu Jiangsu Provincial Key Lab. of Wireless Communications College of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu Provincial Key Lab. of Image Processing and Image Communication College of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

ISBN: (纸本)9781424422517

According to the heterogeneous characteristics of wireless mesh networks and the QoS requirements of multimedia applications, we design a novel QoS adaptive architecture for WMNs that is cross-domain, cross-layer and cross-node. Furthermore, this architecture is mathematically described by using a bi-level programming model. This model uses the optimization results of subnets as the optimization parameters or optimization constraints of backbone networks, and combines the features of different network domains. Based on this bi-level programming model, we propose an ant colony optimization based routing algorithm. Simulation results show that the bi-level programming model, which fully optimizes various QoS parameters of paths, can effectively adapt to the heterogeneous characteristics of WMNs so as to obtain the optimal path;the proposed routing algorithm, which has both advantages of low complexity and fast convergence speed, can converge to the theoretical optimal solution of bi-level programming model. © 2008 IEEE.

关键词： Routing algorithms

来源：评论

学校读者我要写书评

暂无评论

Video object matching based on sift algorithm

Video object matching based on sift algorithm

引用

2008 IEEE International Conference Neural Networks and Signal processing, ICNNSP

作者： Xuelong, Hu Yingcheng, Tang Zhenghua, Zhang School of Information Engineering Yangzhou University Yangzhou Jiangsu 225009 China Jiangsu Prov. Key Lab for Image Processing and Image Communication Nanjing University of Posts and Communications Nanjing Jiangsu 210003 China Jiangsu Prov. Key Lab. for Computer Information Processing Technology Suzhou University Suzhou Jiangsu 215006 China

ISBN: (纸本)9781424423118

SIFT (Scale Invariant Feature Transform) is used to solve visual tracking problem, where the appearances of the tracked object and scene background change during tracking. The implementation of this algorithm has five major stages: scale-space extrema detection;keypoint localization;orientation assignment;keypoint descriptor;keypoint matching. From the beginning frame, object is selected as the template, its SIFT features are computed. Then in the following frames, the SIFT features are computed. Euclidean distance between the object's SIFT features and the frames' SIFT features can be used to compute the accurate position of the matched object. The experimental results on real video sequences demonstrate the effectiveness of this approach and show this algorithm is of higher robustness and real-time performance. It can solve the matching problem with translation, rotation and affine distortion between images. It plays an important role in video object tracking and video object retrieval. © 2008 IEEE.

关键词： Tracking (position)

来源：评论

学校读者我要写书评

暂无评论

Robust blind watermark algorithm of color image based on neural network

Robust blind watermark algorithm of color image based on neu...

引用

2008 IEEE International Conference Neural Networks and Signal processing, ICNNSP

作者： Xuelong, Hu Xu, Lian Lin, Chen Yongai, Zheng School of Information Engineering Yangzhou University Yangzhou Jiangsu 225009 China Jiangsu Province Key Lab. for Image Processing and Image Communication Nanjing University of Posts and Communications Nanjing Jiangsu 210003 China Shanghai University of Electrical Power Shanghai 200090 China

ISBN: (纸本)9781424423118

A new algorithm of color image blind watermarking based on BP neural network and wavelet significant tree is proposed. In YCbCr, the luminance component is decomposed with wavelet, and the wavelet significant tree can be found. Then the correlativity among nodes of wavelet significant tree is described by the nonlinear relationship responded by the trained BP neural network. Based on the relationship, the watermark is embedded into wavelet significant trees. Finally, the embedded watermark can be extracted without original image. The experimental results show that the embedded watermark can be extracted preferably in some common attacks, and this algorithm has better transparency and stronger robustness with some comparisons to other algorithms. © 2008 IEEE.

关键词： Neural networks

来源：评论

学校读者我要写书评

暂无评论

Co-cyclic jacket matrix based optimal training design and placement for MIMO OFDM channel estimation

Co-cyclic jacket matrix based optimal training design and pl...

引用

2008 4th IEEE International Conference on Circuits and Systems for communications, ICCSC

作者： Lin, Chengyu Zhang, Wenjun Guo, Ying Xu, Youyun Institute of Image Communication and Information Processing Department of Electronic Engineering Shanghai Jiao Tong University Shanghai 200240 China Shanghai Key Laboratory of Digital Media Processing and Transmissions Shanghai Jiao Tong University Shanghai 200240 China School of Information Science and Engineering Central South University Changsha 410083 China

ISBN: (纸本)9781424417087

This paper deals with optimal training design and placement over multiple OFDM symbols for the least squares (LS) channel estimation in multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. When the number of transmit antennas increases, more pilot tones are required and the transmission efficiency decreases. To solve this problem, the pilot sequences are distributed over multiple OFDM symbols. Motivated by the properties of co-cyclic Jacket matrices, we derive the optimal pilot sequences from co-cyclic Jacket matrices based on the minimum mean square error (MSE) of the LS channel estimation. Simulation results show that the derived optimal pilot sequences over one, two and four OFDM symbols have the same performance, and greatly outperform the orthogonal pilot sequences in slowly time-varying channels. ©2008 IEEE.

关键词： Orthogonal frequency division multiplexing

来源：评论

学校读者我要写书评

暂无评论

Design and Implementation of Embedded Multimedia Surveillance System

Design and Implementation of Embedded Multimedia Surveillanc...

引用

International Workshop on Knowledge Discovery and Data Mining (WKDD)

作者： Yan Liu Ren-Fa Li Cheng Xu Fei Yu School of Computer and Communication Hunan University Changsha China Guangdong Province Key Laboratory of Electronic Commerce Market Application Technology Guangdong University of Business Studies Guangzhou China Provincial Key Laboratory of Image Processing & Image Communication Nanjing University of Posts and Telecommunications Nanjing China

Due to the thrive of networking multimedia, artificial intelligence and embedded system, video surveillance system is evolved from computer-based to embedded-based. This paper presents an intelligent multimedia surveillance system based on embedded video server. Design and implementation issues of this surveillance system are discussed including system architecture, hardware design and software framework. Moreover, practical applications show that our framework can suitable for commercial applications.

关键词： Multimedia systems Artificial intelligence Application software Embedded system Video surveillance Computer networks Embedded computing Intelligent systems Network servers Computer architecture

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：