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    New vector quantization-based techniques for reducing the effect of channel noise in image transmission

    , Article Signal Processing ; Volume 84, Issue 11 SPEC. ISS , 2004 , Pages 2153-2163 ; 01651684 (ISSN) Dianat, R ; Marvasti, F ; Azmi, P ; Talebi, S ; Sharif University of Technology
    Elsevier  2004
    Abstract
    In this paper, new vector quantization (VQ) based techniques for reducing the effect of channel noise in image transmission are introduced. In one of the proposed methods, i.e., component VQ (CVQ), by transmitting the components of code-vectors (and not their indices), we will be able to reduce the effect of channel noise. To decrease the output rate of CVQ, a modification of CVQ called sub-index VQ (SIVQ) is introduced. This method has error-correcting capability as well. Simulation results show that CVQ and SIVQ techniques are robust to channel errors and surpass the conventional method, in which the indices of the selected code-vectors are protected using a Reed-Solomon code. An error... 

    A novel fingerprint image compression technique using wavelets packets and pyramid lattice vector quantization

    , Article IEEE Transactions on Image Processing ; Volume 11, Issue 12 , 2002 , Pages 1365-1378 ; 10577149 (ISSN) Kasaei, S ; Deriche, M ; Boashash, B ; Sharif University of Technology
    2002
    Abstract
    A novel compression algorithm for fingerprint images is introduced. Using wavelet packets and lattice vector quantization, a new vector quantization scheme based on an accurate model for the distribution of the wavelet coefficients is presented. The model is based on the generalized Gaussian distribution. We also discuss a new method for determining the largest radius of the lattice used and its scaling factor, for both uniform and piecewise-uniform pyramidal lattices. The proposed algorithms aim at achieving the best rate-distortion function by adapting to the characteristics of the subimages. In the proposed optimization algorithm, no assumptions about the lattice parameters are made, and... 

    Quantization-unaware double JPEG compression detection

    , Article Journal of Mathematical Imaging and Vision ; Volume 54, Issue 3 , 2016 , Pages 269-286 ; 09249907 (ISSN) Taimori, A ; Razzazi, F ; Behrad, A ; Ahmadi, A ; Babaie Zadeh, M ; Sharif University of Technology
    Springer New York LLC 
    Abstract
    The current double JPEG compression detection techniques identify whether or not an JPEG image file has undergone the compression twice, by knowing its embedded quantization table. This paper addresses another forensic scenario in which the quantization table of a JPEG file is not explicitly or reliably known, which may compel the forensic analyst to blindly reveal the recompression clues. To do this, we first statistically analyze the theory behind quantized alternating current (AC) modes in JPEG compression and show that the number of quantized AC modes required to detect double compression is a function of both the image’s block texture and the compression’s quality level in a fresh... 

    A robust object shape prediction algorithm in the presence of white gaussian noise

    , Article MMM2006: 12th International Multi-Media Modelling Conference, Beijing, 4 January 2006 through 6 January 2006 ; Volume 2006 , 2006 , Pages 418-421 ; 1424400287 (ISBN); 9781424400287 (ISBN) Khansari, M ; Rabiee, H. R ; Asadi, M ; Ghanbari, M ; Sharif University of Technology
    2006
    Abstract
    This paper presents a shape prediction algorithm in a noisy video sequence based on pixel representation in the undecimated wavelet domain. In our algorithm for tracking of user-defined shapes in a noisy sequence of images, the amplitude of coefficients in the best basis tree expansion of the undecimated wavelet packet transform are used as feature vectors (FVs). FVs robustness against noise has been achieved through inherent denoising and edge component separation in the best basis selection algorithm. The algorithm uses these FVs to track the pixels of small square blocks located at the vicinity of the object boundary. Searching for the best-matched block has been performed using... 

    Feedback bit reduction for antenna selection methods in wireless systems

    , Article 2005 13th IEEE International Conference on Networks jointly held with the 2005 7th IEEE Malaysia International Conference on Communications, Kuala Lumpur, 16 November 2005 through 18 November 2005 ; Volume 1 , 2005 , Pages 229-233 ; 1424400007 (ISBN); 9781424400003 (ISBN) Shariatpanahi, P ; Babadi, B ; Hossein Khalaj, B ; Sharif University of Technology
    2005
    Abstract
    A well known method to reduce the intrinsic complexity of Multiple Input Multiple Output (MIMO) systems is to choose a subset of available antennas which have stronger links than the others, in order to perform the specified MIMO algorithm. The data resulted from the antenna selection process (at the receiver side) is sent back to the transmitter side via a feedback channel. There seems to be a need to reduce the number of feedack bits, specially when the number of antennas is not small. In this paper, we investigate the problem of reducing the number of feedback bits in antenna selection techniques. We've proposed two methods using vector quantization techniques to perform feedback bit... 

    Composition of MPEG-7 color and edge descriptors based-on human vision perception

    , Article Visual Communications and Image Processing 2005, Beijing, 12 July 2005 through 15 July 2005 ; Volume 5960, Issue 1 , 2005 , Pages 568-575 ; 0277786X (ISSN) Lakdashti, A ; Kialashaki, N ; Ghonoodi, A ; Soltani, M ; Sharif University of Technology
    2005
    Abstract
    In content based image retrieval similarity measurement is one of the most important aspects in a large image database for efficient search and retrieval to find the best answer for a user query. Color and texture are among the more expressive of the visual features. Considerable work has been done in designing efficient descriptors for these features for applications such as similarity retrieval. The MPEG-7 specifies a standard set of descriptors for color, texture and shape. In the Human Vision System (HVS), visual information is not perceived equally; some information may be more important than other information. The purpose of this paper is to show how the MPEG-7 descriptor based on... 

    Design and implementation of vector quantizer for a 600 bps vocoder based on MELP

    , Article 11th International Conference on Advanced Communication Technology, ICACT 2009, Phoenix Park, 15 February 2009 through 18 February 2009 ; Volume 2 , 2009 , Pages 1487-1490 ; 17389445 (ISSN); 9788955191387 (ISBN) Khalili, F ; Ardebilipour, M ; Sameti, H ; IEEE Communications Society, IEEE ComSoc; IEEE Region 10 and IEEE Daejeon Section; Korean Institute of Communication Sciences, KICS; lEEK Communications Society, IEEK ComSoc; Korean Institute of Information Scientists and Engineers, KIISE; et al ; Sharif University of Technology
    2009
    Abstract
    This paper describes a vector quantization of a 600 bps speech coding parameters based on the Mixed Excitation Linear Prediction (MELP) model, which was accepted as a standard in communication on narrow-band HF channels. The MELP speech coders are robust in difficult background noise environments and intended mostly for military communications. To reduce the bit rate, a joint vector quantization of multi-frame is developed that takes advantage of inherent inter-frame redundancy of the MELP parameters. By grouping parameters of 4 frames into a multi-frame and using vector quantization, bit rate is decreased 4 times and output speech is still intelligible  

    Sequence-to-Sequence Voice Conversion Using Deep Learning

    , M.Sc. Thesis Sharif University of Technology Shadbash, Hamed (Author) ; Sameti, Hossein (Supervisor)
    Abstract
    Apart from the content of the language that expresses the speaker's purpose and intent, human speech also contains other content, including other information such as the identity of the speaker, his or her gender and approximate age, the Intonation and mode of expression, the feeling of the speaker, the parts emphasized in the speech and so on. "Voice conversion" seeks to change the speaker-dependent content in an audio signal so that speaker-independent content (especially language content) remains unchanged. In other words, the purpose in voice conversion is to change the audio signal of speech created by one person in order to create the notion that the same speech was spoken by someone... 

    Secure communication and archiving of low altitude remote sensing data using high capacity fragile data hiding

    , Article Multimedia Tools and Applications ; 2018 ; 13807501 (ISSN) Akhtarkavan, E ; Majidi, B ; Manzuri, M. T ; Sharif University of Technology
    Springer New York LLC  2018
    Abstract
    Fragile data hiding has been extensively used for secure transmission of the sensitive data using cover images, audios and videos. In the past decade, increasingly the remote sensing applications require transmission and archiving of large number of aerial images and videos. Storage and processing of remote sensing data in the public cloud computing and storage platforms, with servers outside the control of the data owners, requires sufficient attention to persevering the privacy of the data. Furthermore, in the past few years the applications of drones and unmanned aerial vehicles demand algorithms designed especially for low altitude remote sensing data. In this paper, a novel fragile data... 

    Decision-making in detecting and diagnosing faults of multivariate statistical quality control systems

    , Article International Journal of Advanced Manufacturing Technology ; Volume 42, Issue 7-8 , 2009 , Pages 713-724 ; 02683768 (ISSN) Akhavan Niaki, T ; Fallah Nezhad, M. S ; Sharif University of Technology
    2009
    Abstract
    A new methodology is proposed in this paper to both monitor an overall mean shift and classify the states of a multivariate quality control system. Based on the Bayesian rule (Montgomery, Introduction to statistical quality control, 5th edn. Wiley, New York, USA, 2005), the belief that each quality characteristic is in an out-of-control state is first updated in an iterative approach and the proof of its convergence is given. Next, the decision-making process of the detection and classification the process mean shift is modeled. Numerical examples by simulation are provided in order to understand the proposed methodology and to evaluate its performance. Moreover, the in-control and... 

    Secure communication and archiving of low altitude remote sensing data using high capacity fragile data hiding

    , Article Multimedia Tools and Applications ; Volume 78, Issue 8 , 2019 , Pages 10325-10351 ; 13807501 (ISSN) Akhtarkavan, E ; Majidi, B ; Manzuri, M. T ; Sharif University of Technology
    Springer New York LLC  2019
    Abstract
    Fragile data hiding has been extensively used for secure transmission of the sensitive data using cover images, audios and videos. In the past decade, increasingly the remote sensing applications require transmission and archiving of large number of aerial images and videos. Storage and processing of remote sensing data in the public cloud computing and storage platforms, with servers outside the control of the data owners, requires sufficient attention to persevering the privacy of the data. Furthermore, in the past few years the applications of drones and unmanned aerial vehicles demand algorithms designed especially for low altitude remote sensing data. In this paper, a novel fragile data... 

    Learning of gaussian processes in distributed and communication limited systems

    , Article IEEE Transactions on Pattern Analysis and Machine Intelligence ; Volume 42, Issue 8 , 2020 , Pages 1928-1941 Tavassolipour, M ; Motahari, S. A ; Manzuri Shalmani, M. T ; Sharif University of Technology
    IEEE Computer Society  2020
    Abstract
    It is of fundamental importance to find algorithms obtaining optimal performance for learning of statistical models in distributed and communication limited systems. Aiming at characterizing the optimal strategies, we consider learning of Gaussian Processes (GP) in distributed systems as a pivotal example. We first address a very basic problem: how many bits are required to estimate the inner-products of some Gaussian vectors across distributed machines? Using information theoretic bounds, we obtain an optimal solution for the problem which is based on vector quantization. Two suboptimal and more practical schemes are also presented as substitutes for the vector quantization scheme. In... 

    Discrimination of wines based on 2D NMR spectra using learning vector quantization neural networks and partial least squares discriminant analysis

    , Article Analytica Chimica Acta ; Volume 558, Issue 1-2 , 2006 , Pages 144-149 ; 00032670 (ISSN) Masoum, S ; Bouveresse, D. J. R ; Vercauteren, J ; Jalali Heravi, M ; Rutledge, D. N ; Sharif University of Technology
    2006
    Abstract
    The learning vector quantization (LVQ) neural network is a useful tool for pattern recognition. Based on the network weights obtained from the training set, prediction can be made for the unknown objects. In this paper, discrimination of wines based on 2D NMR spectra is performed using LVQ neural networks with orthogonal signal correction (OSC). OSC has been proposed as a data preprocessing method that removes from X information not correlated to Y. Moreover, the partial least squares discriminant analysis (PLS-DA) method has also been used to treat the same data set. It has been found that the OSC-LVQ neural networks method gives slightly better prediction results than OSC-PLS-DA © 2005... 

    Wavelet-based 2-D ECG data compression method using SPIHT and VQ coding

    , Article EUROCON 2007 - The International Conference on Computer as a Tool, Warsaw, 9 September 2007 through 12 September 2007 ; December , 2007 , Pages 133-137 ; 142440813X (ISBN); 9781424408139 (ISBN) Sahraeian, S. M. E ; Fatemizadeh, E ; Sharif University of Technology
    2007
    Abstract
    An improved wavelet-based 2-D ECG data compression method is presented which employs a double stage compression. In the first stage the set partitioning in hierarchical trees (SPIHT) algorithm is used to compress the 2-D data array formed by cutting and beat-aligning the heartbeat data sequence. In the second stage vector quantization is applied to the residual image obtained from the previous stage. The 2-D approach utilizes both inter-beat and inter-sample redundancies in the ECG signal The proposed algorithm is applied to several records in the MIT-BIH arrhythmia database. Results show lower Percent Root mean square Difference (PRD) than 1-D methods and several 2-D methods for the same...