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Complex Dynamical Behavior of a Two-Stage Colpitts Oscillator with Magnetically Coupled Inductors

Journal of Chaos 2014年第1期2014卷

作者： V. Kamdoum Tamba H. B. Fotsin J. Kengne F. Kapche Tagne P. K. Talla Department of Physics Laboratory of Electronics and Signal Processing (LETS) Faculty of Science University of Dschang P.O. Box 67 Dschang *** Department of Telecommunication and Network Engineering IUT-Fotso Victor of Bandjoun University of Dschang P.O. Box 134 Bandjoun *** Department of Electrical Engineering Laboratory of Automation and Applied Computer (LAIA) IUT-Fotso Victor of Bandjoun University of Dschang P.O. Box 134 Bandjoun *** Department of Physics Laboratory of Mechanics and Modelling of Physical Systems (L2MPS) Faculty of Science University of Dschang P.O. Box 67 Dschang ***

A five-dimensional (5D) controlled two-stage Colpitts oscillator is introduced and analyzed. This new electronic oscillator is constructed by considering the well-known two-stage Colpitts oscillator with two further elements (coupled inductors and variable resistor). In contrast to current approaches based on piecewise linear (PWL) model, we propose a smooth mathematical model (with exponential nonlinearity) to investigate the dynamics of the oscillator. Several issues, such as the basic dynamical behaviour, bifurcation diagrams, Lyapunov exponents, and frequency spectra of the oscillator, are investigated theoretically and numerically by varying a single control resistor. It is found that the oscillator moves from the state of fixed point motion to chaos via the usual paths of period-doubling and interior crisis routes as the single control resistor is monitored. Furthermore, an experimental study of controlled Colpitts oscillator is carried out. An appropriate electronic circuit is proposed for the investigations of the complex dynamics behaviour of the system. A very good qualitative agreement is obtained between the theoretical/numerical and experimental results.

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REAL-TIME SUPER-RESOLUTION FOR DIGITAL ZOOMING USING FINITE KERNEL-BASED EDGE ORIENTATION ESTIMATION AND TRUNCATED image RESTORATION

REAL-TIME SUPER-RESOLUTION FOR DIGITAL ZOOMING USING FINITE ...

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IEEE International Conference on image processing

作者： Wonseok Kang Jaehwan Jeon Eunsung Lee Changhun Cho Junghoon Jung Taechan Kim Aggelos K. Katsaggelos Joonki Paik Image Processing and Intelligent Systems Laboratory Graduate School of Advanced Imaging Science Multimedia and Film Chung-Ang University Seoul Korea System LSI Samsung Electronics Co. Ltd Suwon Korea Department of Electrical Engineering and Computer Science Northwestern University Evanston IL 60208 USA

ISBN: (纸本)9781479923427

This paper presents a novel real-time super-resolution (SR) method using directionally adaptive image interpolation and image restoration. The proposed interpolation method estimates the edge orientation using steerable filters and performs edge refinement along the estimated edge orientation. Bi-linear and bi-cubic interpolation filters are then selectively used according to the estimated edge orientation for reducing jagging artifacts in slanting edge regions. The proposed restoration method can effectively remove image degradation caused by interpolation using the directionally adaptive truncated constrained least-squares (TCLS) filter. The proposed method provides high-quality magnified images which are similar to or better than the result of advanced interpolation or SR methods without high computational load. Experimental results indicate that the proposed system gives higher peak-to-peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) values than the state-of-the-art image interpolation methods.

关键词： Super-resolution image interpolation image restoration digital zooming

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FREQUENCY-DOMAIN ANALYSIS OF DISCRETE WAVELET TRANSFORM COEFFICIENTS AND THEIR ADAPTIVE SHRINKAGE FOR ANTI-ALIASING

FREQUENCY-DOMAIN ANALYSIS OF DISCRETE WAVELET TRANSFORM COEF...

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IEEE International Conference on image processing

作者： Eunjung Chae Eunsung Lee Wonseok Kang Younghoon Lim Junghoon Jung Taechan Kim Aggelos K. Katsaggelos Joonki Paik Image Processing and Intelligent Systems Laboratory Graduate School of Advanced Imaging Science Multimedia and Film Chung-Ang University Seoul Korea System LSI Samsung Electronics Co. Ltd Suwon Korea Department of Electrical Engineering and Computer Science Northwestern University Evanston IL 60208 USA

ISBN: (纸本)9781479923427

We present an antialiasing method using combined wavelet-Fourier transform and spatially adaptive shrinkage of the transform coefficients. Traditional antialiasing methods employ a simple low-pass filter onto the entire image, so the resulting image loses not only aliasing artifacts but also high-frequency components such as edges and ridges. The proposed algorithm analyzes the property of the LL subband of the discrete wavelet transform (DWT), and reduces aliasing artifacts using patch-adaptive shrinkage of the DWT coefficients. More specifically, an antialiased LL subband is obtained using adaptive patch-based aliasing reduction. To detect an aliased region, we subtract the discrete Fourier transform (DFT) coefficients of the LL subband from the DFT coefficients of antialiased LL subband. The detected aliasing artifacts in the LH, HL, and HH subbands are reduced by patch-wise adaptive shrinkage of the transform coefficients. The resulting antialiased image is obtained using the inverse DWT. The aliasing artifacts can be efficiently reduced by adaptively shrinking wavelet transform coefficients for preserving high-frequency image details. The proposed antialiasing algorithm is suitable for removing aliasing artifacts which frequently occur in imaging sensors with limited resolution.

关键词： Anti-aliasing wavelet-Fourier transform image enhancement patch-adaptive shrinkage antialiasing image enhancement Aliasing shrinkage Artifacts subband domain analysis Coefficients Sensors (image) Frequency-domain analysis discrete Fourier transform

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Modified full abundance-constrained spectral unmixing

Modified full abundance-constrained spectral unmixing

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High-Performance Computing in Remote Sensing II

作者： Wong, Englin Chang, Chein-I Remote Sensing Signal and Image Processing Laboratory Department of Computer Science and Electrical Engineering University of Maryland Baltimore County Baltimore MD 21250 United States

ISBN: (纸本)9780819492791

Abundance fully constrained least squares (FLCS) method has been widely used for spectral unmixing. A modified FCLS (MFCLS) was previously proposed for the same purpose to derive two iterative equations for solving fully abundance-constrained spectral unmixing problems. Unfortunately, its advantages have not been recognized. This paper conducts a comparative study and analysis between FCLS and MFCLS via custom-designed synthetic images and real images to demonstrate that while both methods perform comparably in unmixing data, MFCLS edges out FCLS in less computing time. © 2012 SPIE.

关键词： Iterative methods

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Adaptive image compression using sparse dictionaries

Adaptive image compression using sparse dictionaries

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International Conference on Systems, signals and image processing, IWSSIP

作者： Inbal Horev Ori Bryt Ron Rubinstein Department of Electrical Engineering Signal and Image Processing Laboratory Haifa Israel Department of Computer Science Geometric Image Processing Laboratory Haifa Israel

Transform coding is a widely used image compression technique, where entropy reduction can be achieved by decomposing the image over a dictionary which provides compaction. Existing algorithms, such as JPEG and JPEG2000, utilize fixed dictionaries which are shared by the encoder and decoder. Recently, works utilizing content-specific dictionaries show promising results by focusing on specific classes of images and using highly specialized dictionaries. However, such approaches lose the ability to compress arbitrary images. In this paper we propose an input-adaptive compression approach, which encodes each input image over a dictionary specifically trained for it. The scheme is based on the sparse dictionary structure, whose compact representation allows relatively low-cost transmission of the dictionary along with the compressed data. In this way, the process achieves both adaptivity and generality. Our results show that although this method involves transmitting the dictionary, it remains competitive with the JPEG and JPEG2000 algorithms.

关键词： Dictionaries image coding Transform coding PSNR Sparse matrices Encoding Bit rate

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Automatic B-spline image Registration Using Histogram-based Landmark Extraction

Automatic B-spline Image Registration Using Histogram-based ...

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IEEE-EMBS Conference on Biomedical engineering and Sciences

作者： Abdollah Ghanbari Reza Abbasi-Asl Aboozar Ghaffari Emad Fatemizadeh Biomedical Image and Signal Processing Laboratory (BiSIPL) Department of Electrical Engineering Sharif University of Technology

ISBN: (纸本)9781467316644

Recognition and correction of inhomogeneous displacement caused by patient's movement has been recently discussed as an interesting topic in medical image processing. Considering consistency in general structure of the image during distortion, histogram could be employed as a fast implementation method in feature domain. Accordingly, attribute vectors could be defined for each pixel based on spatial features to find corresponding points in two images. Consequently a point-based and non-rigid transformation approach will be designed. A B-spline image registration has been applied to match those pairs with a defined smoothness factor. This algorithm is a step-by-step registration process controlled by this factor. The proposed algorithm has been applied to brain MR images. The normal mean square error value has been measured between registered and original images and the result shows a significant improvement in the proposed algorithm.

关键词： image Registration Histogram Attribute Vector Feature Extraction Non-rigid B-spline transform

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An automated fine registration of multisensor remote sensing imagery

An automated fine registration of multisensor remote sensing...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Deniz Gerçek Davut Çesmeci M. Kemal Güllü Alp Ertürk Sarp Ertürk Electronics and Telecommunication Engineering Department Kocaeli University Laboratory of Image and Signal Processing Kocaeli Turkey

In this study we propose an automated fine registration of EO-1 Hyperion and IKONOS imagery. An intensity based registration that is area-based and pixelwise is performed to register given images of divergent spatial and spectral resolution. Two similarity measures that are commonplace in image registration; NCC and NMI, and an operation that is particular to image restoration; CTO is adopted as an error measure as a novelty in image registration. We are convinced with the performance and efficiency of CTO compared to other two common methods of intensity-based registration.

关键词： image registration Spatial resolution Measurement uncertainty Vectors Accuracy Sensors

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A laboratory experiment for real-time echo cancellation using a BeagleBoard

A laboratory experiment for real-time echo cancellation usin...

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European DSP Education and Research Conference (EDERC)

作者： Ori Bryt Asaf Elron Pavel Lifshits Tsahee Zidenberg Yair Moshe Nimrod Peleg Department of Electrical Engineering Technion-Israel Institute of Technology Signal and Image Processing Laboratory Haifa Israel

ISBN: (纸本)9781467345965

Practical experience is an important aspect of the training of every engineer. One way to develop such experience is by hands-on laboratory experimentation which involves cutting-edge technology. In this paper, we present a signal processing lab experiment developed for undergraduate students. Throughout the experiment, students first learn the basics of adaptive filtering and implement an adaptive echo cancellation algorithm using MATLAB. Then, students use a software framework for implementing the same echo cancellation algorithm on a BeagleBoard development platform using both ARM and fixed-point DSP cores of an embedded system-on-chip from Texas Instruments. In a relatively short amount of time (8 hours at the lab and a few additional hours of homework), students learn an important signal processing technique, as well as use complex state-of-the-art DSP hardware to implement it as part of an application running in real-time.

关键词： signal processing technique laboratory Experiments Echo cancellers Technology Software Frameworks CANCELLATIONS laboratory experimentation laboratory procedure laboratory SYSTEM ECHO Students adaptive filters Digital signal processing Desmoplakin Gene adaptive echo cancellation

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Robust and efficient change detection algorithm based on 3D line segments

Robust and efficient change detection algorithm based on 3D ...

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IEEE Convention of the electrical and ELectronic Engineers in Israel

作者： Tom Zohar Ido Ariav Meir Bar-Zohar Signal and Image Processing Laboratory Department of Electrical Engineering Technion-Israel Institute of Technology Haifa Israel

In this paper we examine and improve a new approach for change detection (introduced in [1]) which is based on the appearance and disappearance of 3D line segments as seen in a new image. These 3D line segments are estimated from a set of learning images taken from arbitrary viewpoints and under arbitrary light conditions in an unsupervised manner. The main advantage of the proposed method lies in the fact that the change detection is performed by comparing line segments, and not surfaces or gray levels. Computing 3D surfaces in an image can be computationally intensive, and other methods such as image subtraction or cross-correlation are sensitive to lighting conditions and changes in viewpoints. Moreover, most man-made objects such as buildings, cars, and even cities viewed from above consist mainly of straight linesman-made objects, and therefore this method is highly applicable for such structures. The proposed algorithm first focuses on the reconstruction of a set of 3D line segments forming a certain 3D scene using a set of 2D line segments obtained from the learning images in an unsupervised manner, without any prior knowledge on the cameras' positions or relative distance. In the change detection stage, we use the reconstructed 3D scene of line segments to check if changes, such as appearance or disappearance of objects, have occurred in a given test image. This test image can be taken from arbitrary viewpoint and under arbitrary lighting conditions. Our change detection algorithm not only distinguishes between the states of "changed" and "not-changed" line segments, it also classifies the "changed" line segments as appeared - objects that entered the scene in the test image, and disappeared - objects that left the 3D scene reconstructed from the lines of the learning images.

关键词： image segmentation image reconstruction Cameras Lighting Change detection algorithms Solid modeling Clutter

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Single-band infrared texture-based image colorization

Single-band infrared texture-based image colorization

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IEEE Convention of the electrical and ELectronic Engineers in Israel

作者： Tomer Hamam Yedidyah Dordek Deborah Cohen Signal and Image Processing Laboratory (SIPL) Department of Electrical Engineering Technion-Israel Institute of Technology Haifa Israel

Infrared (IR) imaging has a wide variety of applications such as night vision detection and tracking, meteorology radiometers and spectroscopy techniques. An infrared image is a monochrome image, usually presented in grayscale. It has been proved that colorization of IR images can reduce human error and speed up reaction time. Most previously suggested coloring methods use a reference color image, whose characteristic features differ drastically from IR ones. These differences make those features less pertinent to the coloring process. In this paper, we present a novel texture-based method for automatically coloring IR images. The method uses a reference (source) color image, which is selected from a database, built in advance containing various natural scenes. The source image is selected using a texture-matching algorithm that searches for a resemblance to the IR (target) image. The source and target images are divided into texture-based segments and a color segment best match is found for every IR segment. The coloring process is performed for each pair of IR-color segments, and exploits global as well as local features. Results show that our method produces more natural-looking images than achieved heretofore.

关键词： image color analysis image segmentation Color Fractals Gray-scale Databases Vectors

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