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IEEE International Conference on image processing

作者： Ahmed Gawish Paul Fieguth Sebastian Marschall Kostadinka Bizheva Vision and Image Processing (VIP) Lab Dept. of Systems Design Engineering University of Waterloo Dept. of Physics and Astronomy University of Waterloo

ISBN: (纸本)9781479957521

A limitation of Optical Coherence Tomography (OCT) image segmentation is the poor signal-to-noise ratio of the imaging process, particularly because images are sampled quickly, at high resolutions, and in-vivo. Furthermore, speckle noise is generated by the reflections of the OCT LASER. Because OCT is widely used in imaging the cornea, retina, and skin, OCT layer segmentation is of key interest in all applications. In this paper, a multi-resolution parametric active contour is used for OCT segmentation. The proposed method uses an undecimated wavelet transform to obtain scale-dependent noise reduction, while the active contour is initialized with a generalized Hough transform. Experimental results show that the proposed method outperforms classical as well as state-of-the-art methods and segments OCT images with high level of accuracy.

关键词： Undecimated wavelet transform Optical coherence tomography Active contours Hough transform

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Multiuser Massive MIMO Uplink Performance with Mutual Coupling Effects

Multiuser Massive MIMO Uplink Performance with Mutual Coupli...

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IEEE Global Communications Conference

作者： Ran Zi Xiaohu Ge Haichao Wang Jing Zhang Cheng-Xiang Wang Dept. Electronics & Information Engineering Huazhong University of Science & Technology Joint Research Institute for Signal and Image Processing School of Engineering & Physical Sciences Heriot-Watt University

ISBN: (纸本)9781479935130

A multiuser massive MIMO system with mutual coupling is investigated in finite-dimensional channel scenarios. The uplink ergodic achievable rate is analytically derived for a multiuser massive MIMO system equipped with a rectangular planar uniform antenna array at the base station (BS). Numerical results show that the mutual coupling effect reduces the uplink achievable rate of multiuser massive MIMO systems when the antenna distance decreases. But when the size of the antenna array is fixed, the uplink achievable rate increases with the growing of antenna number.

关键词： Massive MIMO Mutual coupling Multiuser MIMO Finite-dimensional channel

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FTFBE: A numerical approximation for fuzzy time-fractional Bloch equation

FTFBE: A numerical approximation for fuzzy time-fractional B...

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IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)

作者： Ali Ahmadian Chee Seng Chan Soheil Salahshour Vembarasan Vaitheeswaran Centre of Image and Signal Processing University of Malaya Kuala Lumpur MALAYSIA Dept. of Computer Engineering Mashhad Branch Islamic Azad University Mashhad IRAN

Fractional calculus has a long successful history of 300 years, as it able to model natural phenomena states more accurately than the differential equations of integer order. With this, it plays an important role in variant disciplines. Recently, variant fractional models for the Bloch equations have been proposed, however, effective numerical methods for the fractional Bloch equation (FBE) are still in the infancy stage. In this paper, we extend the time-fractional Bloch equation (TFBE) to fuzzy field under the generalized Caputo differentiability, such that these extensions have natural relationship between crisp. For this purpose, we adopted the fractional Adams-Bashforth-Moulton (FABM) type predictorcorrector method, and introduced a new variant - the fuzzy fractional ADM (FFABM) to find the numerical solution. In this case, a new theorem concerning the error of our proposed FFADM method is also presented. Finally, the capability of the newly developed numerical methods is demonstrated in a fuzzy fractional-order problem, and it achieves satisfactorily in terms of numerical stability.

关键词： Mathematical model Equations Numerical models Approximation methods Differential equations Error analysis Nuclear magnetic resonance

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Fourier Plane Filtering Revisited - Analogies in Optics and Mathematics

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Sampling Theory, Signal processing, and Data Analysis 2014年第3期13卷 231-248页

作者： Bettina Heise Martin Reinhardt Stefan E. Schausberger Sören Häuser Swanhild Bernstein David Stifter CDL MS-MACH Center of Surface and Nanoanalytics Dept. of Knowledge-Based Mathematical Systems Johannes Kepler University Linz Austria Inst. Applied Analysis TU Bergakademie Freiberg Freiberg Germany Mathematical Image Processing and Data Analysis TU Kaiserslautern Kaiserslautern Germany

In the paper we start with Fourier plane filtering as a classical technique in microscopy, and continue to discuss how this optical processing technique can be related to mathematical transforms and modern wavelet filter types. In particular, we describe the possibilities for exible solutions by means of programmable optics with a spatial light modulator.

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PREDICTION BASED FILTERING AND SMOOTHING TO EXPLOIT TEMPORAL DEPENDENCIES IN NMF

PREDICTION BASED FILTERING AND SMOOTHING TO EXPLOIT TEMPORAL...

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IEEE International Conference on Acoustics, Speech and Signal processing

作者： Nasser Mohammadiha Paris Smaragdis Arne Leijon KTH Royal Institute of Technology Sound and Image Processing Lab Stockholm Sweden University of Illinois at Urbana-Champaign Dept. of Computer Science Dept. of Electrical and Computer Engineering Adobe Systems Inc.

ISBN: (纸本)9781479903573

Nonnegative matrix factorization is an appealing technique for many audio applications. However, in its basic form it does not use temporal structure, which is an important source of information in speech processing. In this paper, we propose NMF-based filtering and smoothing algorithms that are related to Kalman filtering and smoothing. While our prediction step is similar to that of Kalman filtering, we develop a multiplicative update step which is more convenient for nonnegative data analysis and in line with existing NMF literature. The proposed smoothing approach introduces an unavoidable processing delay, but the filtering algorithm does not and can be readily used for on-line applications. Our experiments using the proposed algorithms show a significant improvement over the baseline NMF approaches. In the case of speech denoising with factory noise at 0 dB input SNR, the smoothing algorithm outperforms NMF with 3.2 dB in SDR and around 0.5 MOS in PESQ, likewise source separation experiments result in improved performance due to taking advantage of the temporal regularities in speech.

关键词： Nonnegative matrix factorization (NMF) Probabilistic latent component analysis (PLCA) Prediction Temporal dependencies smoothing NMF protocol Filtration Kalman filtering Information source matrix decomposition Filtering algorithms Speech processing temporal structure Speech SDPR gene

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INTRA-RETINAL LAYER SEGMENTATION OF OPTICAL COHERENCE TOMOGRAPHY USING DIFFUSION MAP

INTRA-RETINAL LAYER SEGMENTATION OF OPTICAL COHERENCE TOMOGR...

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IEEE International Conference on Acoustics, Speech, and Signal processing

作者： Raheleh Kafieh Hossein Rabbani Michael Abramoff Milan Sonka Biomedical Engineering Dept. Medical Image & Signal Processing Research Center Isfahan Univ. of Medical Sciences Isfahan Iran The Iowa Institute for Biomedical Imaging The University of Iowa

ISBN: (纸本)9781479903573

Optical coherence tomography (OCT) is known to be one of the powerful and noninvasive methods in retinal imaging. OCT uses retroreflected light to provide micron-resolution, cross-sectional scans of biological tissues. In contrast to OCT technology development, which has been a field of active research since 1991, OCT image segmentation has only been fully explored during the last decade. In this paper, we introduce a fast segmentation method based on a new kind of spectral graph theory named diffusion maps. The research is performed on spectral domain OCT images depicting normal macular appearance. In contrast to our recent methods of graph based OCT image segmentation, the presented approach does not require edge-based image information and rather relies on regional image texture. Consequently, the proposed method demonstrates robustness in situations of low image contrast or poor layer-to-layer image gradients. This method is tested on thirteen 3D macular SD-OCT images obtained from eyes without pathologies with Topcon 3D OCT-1000 imaging system (with a size of 650 × 512 × 128 voxels and a voxel resolution of 4.81 × 13.67 × 24.41 μm~3). The mean unsigned and signed border positioning errors (mean ± SD) was 8.52±3.13 and -4.61±3.35 micrometers, respectively. The average computation time of the proposed algorithms (implemented with MATLAB) was 12 seconds per 2D slice.

关键词： optical coherence tomography Graph theory diffusion image texture image information TISSUES (BIOLOGY) image CONTRAST image segmentation MATLAB computational time pathology

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VESSEL SEGMENTATION IN imageS OF OPTICAL COHERENCE TOMOGRAPHY USING SHADOW INFORMATION AND THICKENING OF RETINAL NERVE FIBER LAYER

VESSEL SEGMENTATION IN IMAGES OF OPTICAL COHERENCE TOMOGRAPH...

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IEEE International Conference on Acoustics, Speech, and Signal processing

作者： Raheleh Kafieh Hajar Danesh Hossein Rabbani Michael Abramoff Milan Sonka Biomedical Engineering Dept. Medical Image & Signal Processing Research Center Isfahan Univ. of Medical Sciences Isfahan Iran The Iowa Institute for Biomedical Imaging The University of Iowa

ISBN: (纸本)9781479903573

The correct segmentation of blood vessels in optical coherence tomography (OCT) images is an important requirement for better diagnosis of many retinal diseases. Although OCT blood vessel segmentation is often performed by applying vessel detection methods on 2D projection of OCT datasets, some papers investigate the vessel segmentation on OCT slices. The presence of shadows in outer retinal layers is established as the main factor for vessel localization;however, the shadow information fails to localize many important blood vessels. The proposed method is based on anatomical changes of Retinal Nerve Fiber Layer (RNFL) in presence of vessels. In this paper we find the thickening of RNFL by applying a layer segmentation algorithm on OCT slices and combine this information with shadow localization. Furthermore, a vessel detection method based on curvelet transform is also applied on 2D projection of OCTs to be added to localized vessels from OCTs. The results show that combination of vessel detection on 2D projection with vessel localization on OCTs can improve the accuracy up to 0.96 which is promisingly higher than older methods.

关键词： Vessel segmentation OCT image Retinal Nerve Fiber Layer optical coherence tomography Blood Vessels Thickening pressure vessels images 3-glucosaminoglycan sulfate shadows inspection methods segmentation Segmentation Fiber

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NOVEL VARIATIONAL APPROACH FOR THE PERSPECTIVE SHAPE FROM SHADING PROBLEM USING CALIBRATED imageS

NOVEL VARIATIONAL APPROACH FOR THE PERSPECTIVE SHAPE FROM SH...

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IEEE International Conference on image processing

作者： Aly Abdelrahim Hossam Abdelmunim James Graham Aly Farag Computer Vision and Image Processing Laboratory ECE Dept. University of Louisville Louisville KY 40292 USA. Computer and Systems Engineering Department Faculty of Engineering Ain Shams University Cairo 11517 Egypt. ECE Dept. University of Louisville Louisville KY 40292 USA.

ISBN: (纸本)9781479923427

In this paper, We propose a new approach for solving the Lamber-tian shape from shading (SFS) problem. The proposed technique employs image information as well as camera calibration parameters. We claim that the incorporation of camera parameters results in a better surface reconstruction. In this work, we slightly modify this more realistic model in order to take into account the attenuation of the illumination due to distance. We propose a new variational formulation that relates an evolving surface model with image information, taking into consideration that the image is taken by a perspective camera with known parameters. A new energy functional is formulated to incorporate brightness, smoothness, and integrability constraints. All of these terms assume a hyper surface that evolves in time to meet their criteria. Gradient descent optimization with Euler-Lagrange is used for optimization. We constructed a database of real surfaces as a ground-truth for the experiments. The proposed approach shows superior performance when compared with other approaches in the literature.

关键词： camera calibration perspective SFS variational approach camera calibration artificial shade images Perspective image information ground truth surface modeling Surface reconstruction

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Real-time position estimation and tracking of a basketball

Real-time position estimation and tracking of a basketball

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2012 IEEE International Conference on Signal processing, Computing and Control, ISPCC 2012

作者： Chakraborty, Bodhisattwa Meher, Sukadev Digital Image and Speech Processing Lab National Institute of Technology Rourkela Odisha 769008 India Dept. of Electronics and Communication Engineering National Institute of Technology Rourkela Odisha 769008 India

ISBN: (纸本)9781467313179

In this paper, an algorithm to detect the position of a basketball in a real time outdoor video is proposed. The problem of ball detection in sports video arises due to the occlusion of the ball with the players, the presence of many moving objects like spectators, flags, twigs and branches of the tree etc. The ball image is also getting distorted due to the high speed of the ball. Thus the conventional direct detection and tracking algorithm fails in various occasions. It is much advantageous to study the trajectory information of a ball and estimate the ball location using the trajectory information. In this trajectory based algorithm, firstly the ball like objects are detected and a set of ball candidates are generated for each frame. Then the set of candidate trajectories are plotted. From these potential trajectories, the actual ball trajectory is estimated by studying the trajectory information. The missing ball location in any frame can also be predicted by trajectory interpolation technique. In this paper, we also propose an efficient background detection method using the approximate median value of the background pixels, thus achieving a high degree of segmentations of the moving objects in the foreground. This algorithm provides excellent result under a high degree of occlusion and works satisfactorily in the presence of many moving objects along with the ball in the scene. © 2012 IEEE.

关键词： Trajectories

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Ischemia detection via dynamic time warping and fuzzy rules

Ischemia detection via dynamic time warping and fuzzy rules

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IEEE-EMBS International Conference on Biomedical and Health Informatics, BHI 2012. In Conj. with the 8th Int. Symp.on Medical Devices and Biosensors and the 7th Int. Symp. on Biomedical and Health engineering

作者： Farahabadi, Amin Farahabadi, Eiman Rabbani, Hossein Mahjoub, Mohammad Parsa Dehnavi, Alireza Mehri Biomedical Engineering Dept. School of Medicine Isfahan Univ. of Medical Sciences Isfahan Iran Biomedical Engineering Dept. Medical Image and Signal Processing Research Center Isfahan Univ. of Medical Sciences Isfahan Iran School of Medicine Shahid Beheshti Univ. of Medical Sciences Tehran Iran

ISBN: (纸本)9781457721779

Cardiac ischemia is one of the major causes of mortalities in the world. This disease includes a wide range of temporarily disorders such as insufficient blood circulation to myocardium, which leads to myocardial infarction, and consequently, sudden death. Recording electrocardiogram (ECG) signal has an important role in diagnosis of cardiac disease due to its advantages such as easy recording and suitable cost. Generally using techniques based on extraction of ST segments from ECG signal have been always of interest for ischemia detection. In this study, dynamic time warping (DTW) method is employed as a full-automatic tool in diagnosis of ischemic areas. Then, a fuzzy classifier is applied on the extracted features from the ST segment in order to separate the healthy and ischemic cases. The simulation results show an accuracy of 93% in the output of proposed ischemia detection algorithm. © 2012 IEEE.

关键词： Electrocardiography

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