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IEEE International conference on Trust, Security and Privacy in Computing and Communications (TrustCom)

作者： Jehad Al-Sadi Information Technology and Computing Department Arab Open University Amman Jordan

ISBN: (纸本)9781467321723

The new era of the OTIS (optical Transpose Interconnection System) optoelectronic interconnection network architecture is a promising and an interesting alternative for future-generation parallel processing systems. Many enhancements were presented on OTIS topologies included the Extended OTIS-n-Cube interconnection networks. Therefore, all performance improvement characteristics of such a promising architecture need to be investigated; one of which is load balancing technique. This paper focuses on devising an efficient algorithm for load balancing on the promising Extended OTIS-n-Cube interconnection networks. The proposed algorithm is called Factor-optical-Factor Exchange Model (FOFEM). The proposed algorithm in terms of various parameters, including execution time, load balancing accuracy, number of communication steps, and speed is introduced on OTIS-n-Cube interconnection networks is efficient since it can reach the load balancing final state in 2n+1 communication steps.

关键词： Load management Program processors optical fiber communication Algorithm design and analysis Hypercubes Approximation algorithms

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Sparse representation for blind image quality assessment

Sparse representation for blind image quality assessment

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conference on Computer vision and Pattern Recognition (CVPR)

作者： Lihuo He Dacheng Tao Xuelong Li Xinbo Gao School of Electronic Engineering Xidian University Xi'an Shaanxi China Centre for Quantum Computation and Intelligent Systems Faculty of Engineering and Information Technology Sydney University of Technology Broadway NSW Australia Center for OPTical IMagery Analysis and Learning (OPTIMAL) State Key Laboratory of Transient Optics and Photonics Xian Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi'an Shaanxi China

Blind image quality assessment (BIQA) is an important yet difficult task in image processing related applications. Existing algorithms for universal BIQA learn a mapping from features of an image to the corresponding subjective quality or divide the image into different distortions before mapping. Although these algorithms are promising, they face the following problems: (1) they require a large number of samples (pairs of distorted image and its subjective quality) to train a robust mapping; (2) they are sensitive to different datasets; and (3) they have to be retrained when new training samples are available. In this paper, we introduce a simple yet effective algorithm based upon the sparse representation of natural scene statistics (NSS) feature. It consists of three key steps: extracting NSS features in the wavelet domain, representing features via sparse coding, and weighting differential mean opinion scores by the sparse coding coefficients to obtain the final visual quality values. Thorough experiments on standard databases show that the proposed algorithm outperforms representative BIQA algorithms and some full-reference metrics.

关键词： Measurement Databases Training Feature extraction Dictionaries Image quality Transform coding

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Learning multilevel dictionaries for compressed sensing using discriminative clustering

Learning multilevel dictionaries for compressed sensing usin...

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2012 8th International conference on Intelligent information Hiding and Multimedia Signal processing, IIH-MSP 2012

作者： Thiagarajan, Jayaraman J. Ramamurthy, Karthikeyan Natesan Spanias, Andreas Nasiopoulos, Panos School of ECEE SenSIP Center and Industry Consortium Arizona State University Tempe AZ 85287-5716 United States Institute for Computing Information and Cognitive Systems University of British Columbia Vancouver BC V6T 1Z4 Canada

ISBN: (纸本)9780769547121

The performance of sparse recovery using compressed measurements improves when dictionaries learned from training data are used in place of predefined dictionaries. In this paper, we propose to learn incoherent multilevel dictionaries using discriminative clustering in each level. To this end, we present the discriminative K-lines clustering that iterates between identifying the cluster centers and computing the discriminant directions. A scheme for computing representations using the proposed dictionary is also developed. Simulation results for compressed sensing using standard images demonstrate that incorporating incoherence in the dictionary results in improved recovery performance. Furthermore, we implement the proposed algorithms as part of a sparse representations toolbox for the J-DSP software package. © 2012 IEEE.

关键词： Compressed sensing

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Minimizing the error: A study of the implementation of an Integer Split-Radix FFT on an FPGA for medical imaging

Minimizing the error: A study of the implementation of an In...

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IEEE International conference on Field-Programmable Technology (FPT)

作者： Mohammad Reza Mohammadnia Lesley Shannon School of Engineering Science Simon Fraser University Burnaby BC Canada

Fixed-point arithmetic is used to provide faster and smaller implementations in many digital signal processing applications, including medical imaging, at the expense of decreased accuracy. In particular, when a Fast Fourier Transform (FFT)-Inverse Fast Fourier Transform (IFFT) pair are required as part of the calculation, the error introduced into the calculations can be significant. For some applications, such as Fourier Domain optical Coherence Tomography (FD-OCT), this degradation is unacceptable. Our study shows that using a conventional fixed-point FFT-IFFT pair, such as Xilinx's FFT core, can produce an average 6-bit error for a 1024-point FFT using 12-bit input data in a 32-bit arithmetic system. The majority of the error is caused by quantization effects, particularly on the phase information of input signal. For this reason, in phase sensitive applications such as FD-OCT, the error dominates the fixed-point calculation: 78% in 16-bit and 51% in 32-bit systems. This work presents a parameterized 32 to 4096-point integer FFT implementation for FPGAs that uses a Split-Radix algorithm to reduce the number of multiplies and improve latency. Integer FFTs are perfectly reconstructible, with zero reconstruction error. Here, we specifically analyze a 1024-point Integer Split-Radix FFT (Int-SRFFT) and IFFT pair that perfectly reconstructs the original 12-bit input data using 22-bit arithmetic, compared to the average 6-bit error for a 1024-point FFT using 32-bit fixed-point arithmetic. The pipelined architecture of this design has a latency of 29.06us for a 1024-point FFT, and a throughput of more than 34 thousand 1024-point FFTs/second for a 22-bit datapath at an operating frequency of 274MHz. Although our Int-SRFFT is perfectly reconstructible, compared to Xilinx's fixed-point FFT, it has ~6% more flipflops, ~63% more LUTs, 5.3x more BRAMs, and a ~44% increase in latency. However, compared to a previous fixed-point SRFFT design on an FPGA, our throughput is 15.5x

关键词： Algorithm design and analysis Signal processing algorithms Field programmable gate arrays Discrete Fourier transforms Fixed-point arithmetic Frequency domain analysis

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Joint-Polarization Phase Recovery algorithms for DP-16-QAM Coherent optical systems

Joint-Polarization Phase Recovery Algorithms for DP-16-QAM C...

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13th International conference on Transparent optical Networks (ICTON)

作者： Mello, Darli A. A. Mueller, Rafael R. Portela, Thiago F. Olsson, Bengt-Erik Univ Brasilia Dept Elect & Engn POB 4386 BR-70919970 Brasilia DF Brazil Ericsson Res Molndal Sweden

ISBN: (纸本)9781457708800

Dual-Polarization 16-QAM coherent systems are a spectrally efficient alternative to future optical networks with metropolitan dimensions. However, the close-packed constellation of the 16-QAM modulation format also has drawbacks, such as an increased susceptibility to phase noise generated in the transmitter and local oscillator lasers. This paper evaluates basic phase recovery algorithms developed for DP-16-QAM systems, using computer simulations and the offline post-processing of experimental data. Special attention is given to joint-polarization algorithms, which use the phase information of both polarization orientations to jointly produce a single estimate of the phase noise, thus relaxing the requirements for transmitter and local oscillator lasers.

关键词： optical transmission coherent detection phase-recovery polarization multiplexing

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optical signal processing: Holography, speckle and algorithms

Optical signal processing: Holography, speckle and algorithm...

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Signal Recovery and Synthesis, SRS 2011

作者： Sheridan, John T. Communications and Optoelectronic Research Centre SFI Strategic Research Cluster in Solar Energy Conversion School of Electrical Electronic and Mechanical Engineering Univ. College Dublin Belfield Dublin D4 Ireland

ISBN: (纸本)9781557529145

Modeling the propagation of light through free space and simple paraxial systems continue to be enduring, and practically important topics in optics. Is there anything new or interesting that remains to be said? Given the pervasive use of digital cameras and numerical algorithms, examples are given indicating that the answer is yes. Satisfactory modeling requires the interactions of the whole optical information processing system (optics, optoelectronics and software) be included. ©2010 optical Society of America.

关键词： optical data processing

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A new two-DOF rotational optical image stabilizer

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MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOsystems-information STORAGE AND processing systems 2011年第5-7期17卷 1037-1049页

作者： Chao, Paul C-P Chen, Yu-Han Chiu, Chi-Wei Tsai, Meng-Yen Chang, Jyh-Yeong Lin, Shir-Kuan Natl Chiao Tung Univ Dept Elect Engn Hsinchu 300 Taiwan Natl Chiao Tung Univ Inst Imaging & Biomed Phon Tainan 711 Taiwan

This work proposes design, optimization and validation of a new two degree-of-freedom (DOF) rotational optical image stabilizer (OIS) that is suitable for installing into a mobile-phone-camera. This OIS differs from the previous designs since it stabilizes the lens holder directly by two-DOF translational mechanisms that are actuated by voice coil motors. The work can be divided into three main parts: (1) designs of mechanism and genetic algorithm (GA) optimization of magnetic field, (2) establishments of the dynamic model and equation of motions (EOM) of a dual-axis rotational structure, and (3) realizations of a sliding mode control (SMC) controller with fine performance. The dynamic of the dual-axis rotational OIS system has been analyzed and the EOM has been derived. Based on the Lagrange's method, the motions of the OIS have been modeled through considering kinetic energy and electromagnetic torques. In the last part, the theory of SMC is applied, and the associated simulations are conducted. Based on the simulation results, the SMC controller is forged with the assistances from MATLAB pre-simulation and tested by a microprocessor module. After a series of experiments and verifications, the prototype of the novel OIS is finally accomplished with satisfactory performance of vibration reduction.

关键词： DEGREES of freedom GENETIC algorithms COMBINATORIAL optimization algorithms MAGNETIC fields

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A comparison of optical flow techniques for a blind spot camera

A comparison of optical flow techniques for a blind spot cam...

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IADIS International conference Computer Graphics, visualization, Computer vision and Image processing 2011, Part of the IADIS Multi conference on Computer Science and information systems 2011, MCCSIS 2011

作者： Van Den Heuvel, Lorenz Van Beeck, Kristof Goedemé, Toon Lessius Mechelen Association K.U. Leuven Jan De Nayerlaan 5 2860 Sint-Katelijne-Waver Belgium

ISBN: (纸本)9789728939489

In this paper we present an overview and comparison of the most important optical flow calculation techniques. Our comparison is based upon three aspects: accuracy, speed and robustness against noise. Based on the results of our comparison, we determine which of the algorithms is best suited for real-time implementation on dedicated hardware. This decision is based on the trade-off that we found between our evaluation aspects. In the future we will use this result to achieve the automatic detection of vulnerable road users using a blind spot camera. © 2011 IADIS.

关键词： Computer vision

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Advanced 2D die placement inspection system for reliable flip chip interconnections based on 3D information of die and substrate by a phase measuring profilometry

Advanced 2D die placement inspection system for reliable fli...

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conference on optical Measurement systems for Industrial Inspection viI

作者： Lee, Hyun-Kee Kim, Min Young Koh Young Technol Inc R&D Ctr Vis Team F15 Halla Sigma Valley345-90 Gasan Dong Seoul 153802 South Korea Kyungpook Natl Univ Sch Elect Engn Taegu 702701 South Korea

ISBN: (纸本)9780819486783

To use flip chip interconnection technology for semiconductor packages offers a number of possible advantages to the user: reduced signal inductance, reduced power/ground inductance, higher signal density, die shrink, and reduced package footprint. However, manufacturing processes for 'flipchip'-integrated packages need a high precision alignment between flip chip and matched substrate. Comparing with original visual alignment based on 2D image information, an advanced die placement inspection system for reliable flip chip interconnections has been firstly proposed by authors [2]. In this paper, the proposed system is reviewed briefly, and system calibration algorithms and information processing algorithms are described in detail. To verify the system performance, a series of real experiments is performed on flip chip packages for high performance computing, and its results are discussed in detail.

关键词： Die placement inspection three-dimensional measurement phase measuring profilometry

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High-Resolution Digital Zooming Using a Fisheye Lens and Geometric Compensation

High-Resolution Digital Zooming Using a Fisheye Lens and Geo...

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IEEE International conference on Consumer Electronics (ICCE 2011)

作者： Kim, Donggyun Kang, Wonseok Paik, Joonki Chung Ang Univ Grad Sch Adv Imaging Sci Multimedia & Film Image Proc & Intelligent Syst Lab Seoul 156756 South Korea

ISBN: (纸本)9781424487127

A computational camera uses unconventional optics and digital signal processing software to produce new forms of visual information [1]. This paper presents a computational camera approach to near-lossless, high-quality digital zooming employed in compact comsumer's imaging devices result in severe distortions in output images due to the limited amount of information. In spite of such limited quality, the digital zooming function is equipped in many inexpensive cameras because of its desirable properties such as compactness, low power consumption, and low cost. In order to overcome the limited quality of the conventional digital zooming system, we use a fisheye lens with appropriate digital image processing algorithms. For realization of the proposed computational camera-based digital zooming, we first generate intput test images using a commercial optical simulator. We then calibrate the fisheye lens using a special rectangular grid patterns. Finally, we remove the barrel distortion in the output of the fisheye lens, and crop an appropriate size of rectangular region in the center. Experimental results indicate that the proposed computational camera-based digital Zooming system can significantly increase the resolution of output images compared with con ventional digital zooming systems, especially at magnification ratio of 3 or higher.

关键词： Digital signal processing

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