Now showing items 1-23 of 23

  • Adding Linguistic Constraints to Document Image Decoding: Comparing the Iterated Complete Path and Stack Algorithms 

    Popat, Kris; Greene, Dan; Romberg, Justin; Bloomberg, Dan (2001-01-20)
    Beginning with an observed document image and a model of how the image has been degraded, Document Image Decoding recognizes printed text by attempting to find a most probable path through a hypothesized Markov source. The ...
  • 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 

    Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2000-04-01)
    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 statistics of the wavelet coefficients ...
  • 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 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 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 ...
  • A Geometric Hidden Markov Tree Wavelet Model 

    Romberg, Justin; Wakin, Michael; Choi, Hyeokho; Baraniuk, Richard G. (2003-08-01)
    In the last few years, it has become apparent that traditional wavelet-based image processing algorithms and models have significant shortcomings in their treatment of edge contours. The standard modeling paradigm exploits ...
  • Geometric Methods for Wavelet-Based Image Compression 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2003-08-01)
    Natural images can be viewed as combinations of smooth regions, textures, and geometry. Wavelet-based image coders, such as the space-frequency quantization (SFQ) algorithm, provide reasonably efficient representations for ...
  • Geometric Tools for Image Compression 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2002-11-01)
    Images typically contain strong geometric features, such as edges, that impose a structure on pixel values and wavelet coefficients. Modeling the joint coherent behavior of wavelet coefficients is difficult, and standard ...
  • Hidden Markov Tree Modeling of Complex Wavelet Transforms 

    Choi, Hyeokho; Romberg, Justin; Baraniuk, Richard G.; Kingsbury, Nicholas G. (2000-06-01)
    Multiresolution signal and image models such as the hidden Markov tree aim to capture the statistical structure of smooth and singular (edgy) regions. Unfortunately, models based on the orthogonal wavelet transform suffer ...
  • Hidden Markov Tree Models for Complex Wavelet Transforms 

    Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G.; Kingsbury, Nicholas G. (2002-05-01)
    Multiresolution models such as the hidden Markov tree (HMT) aim to capture the statistical structure of signals and images by leveraging two key wavelet transform properties: wavelet coefficients representing smooth/singular ...
  • Image Compression using an Efficient Edge Cartoon + Texture Model 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2002-04-01)
    Wavelet-based image coders optimally represent smooth regions and isolated point singularities. However, wavelet coders are less adept at representing perceptually important edge singularities, and coding performance ...
  • Multiplicative Multiscale Image Decompositions: Analysis and Modeling 

    Romberg, Justin; Riedi, Rudolf H.; Choi, Hyeokho; Baraniuk, Richard G. (2000-07-01)
    Multiscale processing, in particular using the wavelet transform, has emerged as an incredibly effective paradigm for signal processing and analysis. In this paper, we discuss a close relative of the Haar wavelet transform, ...
  • Multiscale Classification using Complex Wavelets and Hidden Markov Tree Models 

    Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G.; Kingsbury, Nicholas G. (2000-09-01)
    Multiresolution signal and image models such as the hidden Markov tree (HMT) aim to capture the statistical structure of smooth and singular (textured and edgy) regions. Unfortunately, models based on the orthogonalwavelet ...
  • Multiscale Edge Grammars for Complex Wavelet Transforms 

    Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2001-10-01)
    Wavelet domain algorithms have risen to the forefront of image processing. The power of these algorithms is derived from the fact that the wavelet transform restructures the image in a way that makes statistical modeling ...
  • Multiscale Geometric Image Processing 

    Romberg, Justin; Wakin, Michael; Baraniuk, Richard G. (2003-07-01)
    Since their introduction a little more than 10 years ago, wavelets have revolutionized image processing. Wavelet based algorithms define the state-of-the-art for applications including image coding (JPEG2000), restoration, ...
  • Multiscale Image Segmentation Using Joint Texture and Shape Analysis 

    Neelamani, Ramesh; Romberg, Justin; Riedi, Rudolf H.; Choi, Hyeokho; Baraniuk, Richard G. (2000-07-01)
    We develop a general framework to simultaneously exploit texture and shape characterization in multiscale image segmentation. By posing multiscale segmentation as a model selection problem, we invoke the powerful framework ...
  • Multiscale Wedgelet Image Analysis: Fast Decompositions and Modeling 

    Romberg, Justin; Wakin, Michael; Baraniuk, Richard G. (2002-06-01)
    The most perceptually important features in images are geometrical, the most prevalent being the smooth contours ("edges") that separate different homogeneous regions and delineate distinct objects. Although wavelet based ...
  • Rate-Distortion Optimized Image Compression using Wedgelets 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2002-06-01)
    Most wavelet-based image coders fail to model the joint coherent behavior of wavelet coefficients near edges. Wedgelets offer a convenient parameterization for the edges in an image, but they have yet to yield a viable ...
  • Shift-Invariant Denoising using Wavelet-Domain Hidden Markov Trees 

    Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (1999-10-20)
    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 statistics of the wavelet coefficients ...
  • Shift-Invariant Denoising using Wavelet-Domain 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 statistical signal and image processing. The hidden Markov tree (HMT) model captures the key features of the joint statistics of the wavelet coefficients ...
  • Wavelet-domain Approximation and Compression of Piecewise Smooth Images 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2005-01-15)
    The wavelet transform provides a sparse representation for smooth images, enabling efficient approximation and compression using techniques such as zerotrees. Unfortunately, this sparsity does not extend to <i>piecewise ...
  • Wavelet-Domain Approximation and Compression of Piecewise Smooth Images 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2006-05-01)
    The wavelet transform provides a sparse representation for smooth images, enabling efficient approximation and compression using techniques such as zerotrees. Unfortunately, this sparsity does not extend to piecewise smooth ...