Now showing items 1-20 of 90

    • 3D Geometry Coding using Mixture Models and the Estimation Quantization Algorithm 

      Lavu, Sridhar (2002-09-01)
      3D surfaces are used in applications such as animations, 3D object modeling and visualization. The geometries of such surfaces are often approximated using polygonal meshes. This thesis aims to compress 3D geometry meshes ...
    • Adaptive Representation of JPEG 2000 Images Using Header-based Processing 

      Neelamani, Ramesh; Berkner, Kathrin (2002-09-20)
      To bridge the mismatch between the sizes of images and display devices, we present an efficient and automatic algorithm to create an adaptive image representation called SmartNail. Given a digital image and rectangular ...
    • Adaptive Wavelet Transforms for Image Coding 

      Claypoole, Roger L.; Davis, Geoffrey; Sweldens, Wim; Baraniuk, Richard G. (1997-11-01)
      We introduce a new adaptive transform for wavelet-based image coding. The lifting framework for wavelet construction motivates our analysis and provides new insight into the problem. Since the adaptive transform is non-linear, ...
    • Adaptive Wavelet Transforms for Image Coding 

      Claypoole, Roger L.; Davis, Geoffrey; Sweldens, Wim; Baraniuk, Richard G. (1997-11-01)
      We introduce a new adaptive transform for wavelet-based image coding. The lifting framework for wavelet construction motivates our analysis and provides new insight into the problem. Since the adaptive transform is non-linear, ...
    • Adaptive Wavelet Transforms via Lifting 

      Claypoole, Roger L.; Baraniuk, Richard G.; Nowak, Robert David (1999-01-15)
      This paper develops new algorithms for adapted multiscale analysis and signal adaptive wavelet transforms. We construct our adaptive transforms with the <i>lifting scheme</i>, which decomposes the wavelet transform into ...
    • Adaptive Wavelet Transforms via Lifting 

      Claypoole, Roger L.; Baraniuk, Richard G.; Nowak, Robert David (1998)
      This paper develops new algorithms for adapted multiscale analysis and signal adaptive wavelet transforms. We construct our adaptive transforms with the <i>lifting scheme</i>, which decomposes the wavelet transform into ...
    • Adaptive Weighted Highpass Filters Using Multiscale Analysis 

      Nowak, Robert David; Baraniuk, Richard G. (1998-07-01)
      In this paper, we propose a general framework for studying a class of weighted highpass filters. Our framework, based on a multiscale signal decomposition, allows us to study a wide class of filters and to assess the ...
    • Analysis of Multiscale Texture Segmentation using Wavelet-Domain Hidden Markov Trees 

      Choi, Hyeokho; Hendricks, Brent; Baraniuk, Richard G. (1999-10-01)
      This paper describes a technique for estimating the Kullback-Leibler (KL) distance between two Hidden Markov Models (HMMs), and for measuring the quality of the estimator. It also provides some results based on applying ...
    • Approximation and Compression of Piecewise Smooth Images Using a Wavelet/Wedgelet Geometric Model 

      Romberg, Justin; Wakin, Michael; Baraniuk, Richard G. (2003-09-01)
      Inherent to photograph-like images are two types of structures: large smooth regions and geometrically smooth edge contours separating those regions. Over the past years, efficient representations and algorithms have been ...
    • Bayesian Tree-Structured Image Modeling using Wavelet-domain Hidden Markov Models 

      Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (1999-07-20)
      Wavelet-domain hidden Markov models have proven to be useful tools for statistical signal and image processing. The hidden Markov tree (HMT) model captures the key features of the joint probability density of the wavelet ...
    • Bayesian Tree-Structured Image Modeling using Wavelet-domain Hidden Markov Models 

      Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2001-07-01)
      Wavelet-domain hidden Markov models have proven to be useful tools for statistical signal and image processing. The hidden Markov tree (HMT) model captures the key features of the joint probability density of the wavelet ...
    • Bayesian Wavelet Domain Image Modeling using Hidden Markov Trees 

      Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (1999-10-01)
      Wavelet-domain hidden Markov models have proven to be useful tools for statiscal signal and image processing. The hidden Markov tree (HMT) model captures the key features o teh join statistics of the wavelet coefficients ...
    • Coherent Multiscale Image Processing using Quaternion Wavelets 

      Chan, Wai Lam; Choi, Hyeokho; Baraniuk, Richard G. (2006-10-01)
      The quaternion wavelet transform (QWT) is a new multiscale analysis tool for geometric image features. The QWT is a near shift-invariant tight frame representation whose coefficients sport a magnitude and three phases: ...
    • Compound Poisson Cascades 

      Chainais , Pierre; Riedi, Rudolf H.; Abry, Patrice (2002-05-01)
      Multiplicative processes and multifractals proved useful in various applications ranging from hydrodynamic turbulence to computer network traffic, to name but two. Placing multifractal analysis in the more general framework ...
    • Detecting Periodic Behavior in Nonstationary Signals 

      Venkatachalam, Vidya; Aravena, Jorge.L. (1998-10-20)
      This paper presents results on the multiresolution analysis of nonstationary signals with the objective of detecting underlying periodic phenomena. Wavelet packet analysis with coefficient thresholding is the basis for the ...
    • Directional Complex-Wavelet Processing 

      Fernandes, Felix; van Spaendonck, Rutger; Burrus, C. Sidney (2000-08-20)
      Poor directional selectivity, a major disadvantage of the separable 2D discrete wavelet transform (DWT), has previously been circumvented either by using highly redundant, nonseparable wavelet transforms or by using ...
    • Directional Hypercomplex Wavelets for Multidimensional Signal Analysis and Processing 

      Chan, Wai Lam; Choi, Hyeokho; Baraniuk, Richard G. (2004-05-01)
      We extend the wavelet transform to handle multidimensional signals that are smooth save for singularities along lower-dimensional manifolds. We first generalize the complex wavelet transform to higher dimensions using a ...
    • Directional, Shift-Insensitive, Complex Wavelet Transforms with Controllable Redundancy 

      Fernandes, Felix (2001-08-20)
      Although the Discrete Wavelet Transform (DWT) is a powerful tool for signal and image processing, it has three serious disadvantages. First, the DWT is shift sensitive because input-signal shifts generate unpredictable ...
    • Distributed Wavelet Transform for Irregular Sensor Network Grids 

      Wagner, Raymond; Choi, Hyeokho; Baraniuk, Richard G.; Delouille, Veronique (2005-07-01)
      Wavelet-based distributed data processing holds much promise for sensor networks; however, irregular sensor node placement precludes the direct application of standard wavelet techniques. In this paper, we develop a new ...
    • Diverging moments and parameter estimation 

      Goncalves, Paulo; Riedi, Rudolf H. (2004-01-15)
      Heavy tailed distributions enjoy increased popularity and become more readily applicable as the arsenal of analytical and numerical tools grows. They play key roles in modeling approaches in networking, finance, hydrology ...