Hyeokho Choi

OPEN-CONTENT SIGNAL PROCESSING LABORATORIES IN CONNEXIONS (2009)

Richard Baraniuk, Matthew Berry, Mark Butala O, Hyeokho Choi, Mark Ham, Douglas L. Jones, ...

Due to inherent factors such as a small and fragmented market and rapid hardware obsolescence, the conventional textbook is inadequate for DSP laboratory education. Freely available open-content...

Community Driven Digital Signal Processing Laboratories (2009)

In Connexions, Richard Baraniuk, Hyeokho Choi, Douglas L. Jones, Lee Potter

The conventional textbook is largely inadequate for digital signal processing (DSP) laboratory education due to inherent factors such as a small and fragmented market and rapid hardware obsolescence....

Coherent Multiscale Image Processing using Dual-Tree (2008)

Quaternion Wavelets, Wai Lam Chan, Hyeokho Choi, Richard G. Baraniuk

The dual-tree 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...

Baraniuk R.: Geometric Tools for Image Compression (2008)

Michael Wakin, Justin Romberg, Hyeokho Choi, Richard Baraniuk

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...

Geometry Compression of Normal Meshes Using Rate-Distortion Algorithms (2008)

L. Kobbelt, P. Schröder, Sridhar Lavu, Hyeokho Choi, Richard Baraniuk

We propose a new rate-distortion based algorithm for compressing 3D surface geometry represented using triangular normal meshes. We apply the Estimation-Quantization (EQ) algorithm to compress normal...

Coherent Multiscale Image Processing using Quaternion (2008)

Wai Lam Chan, Hyeokho Choi, Richard G. Baraniuk

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...

DISTRIBUTED MULTISCALE DATA ANALYSIS AND PROCESSING FOR SENSOR NETWORKS (2008)

Raymond Wagner, Shriram Sarvotham, Hyeokho Choi, Richard Baraniuk

While multiresolution data analysis, processing, and compression hold considerable promise for sensor network applications, progress has been confounded by two factors. First, typical sensor data are...

Analysis of Multiscale Texture Segmentation using Wavelet-Domain Hidden Markov Models (2008)

Hyeokho Choi, Brent Hendricks, Richard Baraniuk

Wavelet-domain Hidden Markov Tree (HMT) models are powerful tools for modeling the statistical properties of wavelet transforms. By characterizing the joint statistics of the wavelet coefficients,...

Multiscale texture segmentation of dip-cube slices using wavelet-domain hidden Markov trees (2008)

Ivan Magrin-chagnolleau, Hyeokho Choi, Rutger Van Spaendonck, Richard G. Baraniuk

Wavelet-domain hidden Markov models (HMMs) are powerful tools for modeling the statistical properties of wavelet transforms. By characterizing the joint statistics of wavelet coe cients, HMMs e...

Wavelet Statistical Models and Besov Spaces (2007)

Hyeokho Choi, Richard Baraniuk

We discover a new relationship between two seemingly different image modeling methodologies; the Besov space theory and the wavelet-domain statistical image models. Besov spaces characterize the set...

Multiscale texture segmentation of dip-cube slices using wavelet-domain hidden Markov trees (2007)

Hyeokho Choi, Rutger Van Spaendonck, Richard G. Baraniuk

this paper, we introduce a new multiscale texture segmentation algorithm based on wavelet-domain hidden Markov trees (HMTs). We apply this new technique to the segmentation of dip-cube time slices.

Isar Imaging Of Approaching Targets (2007)

Hyeokho Choi, Andrew W. Krone, David C. Munson

This paper develops a theory for high-resolution, microwave radar imaging of approaching targets, using concepts from synthetic aperture radar. The target to be imaged is assumed to be approaching a...

Multiscale texture segmentation of dip-cube slices using wavelet-domain hidden Markov trees (2007)

Hyeokho Choi, Rutger Van Spaendonck, Richard G. Baraniuk

this paper, we introduce a new multiscale texture segmentation algorithm based on wavelet-domain hidden Markov trees (HMTs). We apply this new technique to the segmentation of dip-cube time slices.

Multiscale texture segmentation of dip-cube slices using wavelet-domain hidden Markov trees (2007)

Ivan Magrin-chagnolleau, Hyeokho Choi, Rutger Van Spaendonck, Richard G. Baraniuk

Wavelet-domain hidden Markov models (HMMs) are powerful tools for modeling the statistical properties of wavelet transforms. By characterizing the joint statistics of wavelet coe cients, HMMs e...

Baraniuk R.: Geometric Tools for Image Compression (2007)

Michael Wakin, Justin Romberg, Hyeokho Choi, Richard Baraniuk

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...

Image Compression using an Ecient Edge Cartoon + Texture Model (2007)

Michael Wakin, Justin Romberg, Hyeokho Choi, Richard Baraniuk

dsp.rice.edu Wavelet-based image coders optimally represent smooth regions and isolated point singularities. However, wavelet coders are less adept at representing perceptually important edge...

Estimation-Quantization Geometry Coding Using Normal Meshes (2007)

Sridhar Lavu, Hyeokho Choi, Richard Baraniuk

dsp.rice.edu We propose a new algorithm for compressing three-dimensional triangular mesh data used for representing surfaces. We apply the Estimation-Quantization (EQ) algorithm originally designed...

OPEN-CONTENT SIGNAL PROCESSING LABORATORIES IN CONNEXIONS (2007)

Richard Baraniuk, Matthew Berry, Mark Butala, Hyeokho Choi, Mark Haun, Michael Kramer, ...

Due to inherent factors such as a small and fragmented market and rapid hardware obsolescence, the conventional textbook is inadequate for DSP laboratory education. Freely available open-content...

a (2007)

Unoma Ndili, Robert Nowak, Richard Baraniuk, Hyeokho Choi

In this paper, a coding theoretic approach is presented for the unsupervised segmentation of SAR images. The approach implements Rissanen's concept of Minimum Description Length (MDL) for...

Analysis of Multiscale Texture Segmentation using Wavelet-Domain Hidden Markov Models (2007)

Hyeokho Choi, Brent Hendricks, Richard Baraniuk

Wavelet-domain Hidden Markov Tree (HMT) models are powerful tools for modeling the statistical properties of wavelet transforms. By characterizing the joint statistics of the wavelet coefficients,...

Wavelet-domain approximation and compression of piecewise smooth images (2006)

Wakin, Michael B., Romberg, Justin K., Choi, Hyeokho, Baraniuk, Richard G.

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...

Wavelet-domain approximation and compression of piecewise smooth images (2006)

Michael B. Wakin, Student Member, Justin K. Romberg, Hyeokho Choi, Senior Member, Richard G. Baraniuk

Abstract—The wavelet transform provides a sparse representation for smooth images, enabling efficient approximation and compression using techniques such as zerotrees. Unfortunately, this sparsity...

Wavelet-domain approximation and compression of piecewise smooth images (2006)

Michael B. Wakin, Justin K. Romberg, Hyeokho Choi, Richard G. Baraniuk

Abstract — The wavelet transform provides a sparse representation for smooth images, enabling efficient approximation and compression using techniques such as zerotrees. Unfortunately, this...

Rice DSP Lab Setup (2005)

Hyeokho Choi

The intent of this module is to describe the laboratory equipment and hardware setup at Rice University DSP Laboratory.

FIR Filter Design using MATLAB (2005)

Hyeokho Choi

This module explains the MATLAB commands for FIR filter design.

MATLAB FIR Filter Design Exercise (2005)

Hyeokho Choi

This is FIR filter design exercise in MATLAB.

Assembly Implementation of FIR Filters on TI TMS320C62x (2005)

Hyeokho Choi

This module is the exercise to implement FIR filtering in TI TMS320C62x assembly.

Testing Filters in Rice DSP Lab (2005)

Hyeokho Choi

This module explains how to test the implemented discrete-time filters in Rice DSP laboratory.

Linear Assembly Implementation of FIR Filters on TMS320C62x (2005)

Hyeokho Choi

This module is an exercise to implement FIR filters using TI linear assembly on TMS320C62x.

TMS320C6211 Architecture Overview (2005)

Hyeokho Choi

This module describes the basic architecture of Texas Instruments TMS320c6211 CPU.

Fixed Point Arithmetic and Q format (2005)

Hyeokho Choi

This module explains the fixed point, finite-precision fractional number representation.

C Language Implementation of FIR Filters on TMS320C62x (2005)

Hyeokho Choi

C language implementation of FIR filters on TMS320C62x.

Implementation of Q-15 arithmetic on TI TMS320C62x (2005)

Hyeokho Choi

This explains how to implenet Q-15 multiplication on TMS320C62x CPU.

C62x Assembly Primer II (2005)

Hyeokho Choi

You will learn more assembly instructions in this lab.

Interrupts (2005)

Hyeokho Choi

An overview of the usage of interrupts with the C62x CPU.

TI Code Composer Studio V2.x Primer (2005)

Hyeokho Choi

This module is a primer for the hardware and software to write, debug, and run DSP programs on the TI C6211 DSP Starter Kit (DSK) board.

Using C and Linear ASM (2005)

Hyeokho Choi

In this module you will learn basic C programming using TI's optimizing C compiler.

A/D, D/A, and Sampling (2005)

Hyeokho Choi

This will acquaint you with the peripheral setup on the C6211 DSK board for A/D and D/A conversion.

C62x Assembly Primer 1 (2005)

Hyeokho Choi

Introduction to the basic C62x architecture and instruction set.

FIR Filtering (2005)

Hyeokho Choi

This module is an overview of the design and implementation of FIR filtering.

Distributed Wavelet Transform for Irregular Sensor Network Grids (2005)

Raymond Wagner, Hyeokho Choi, Richard Baraniuk

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...

Terahertz wide aperture reflection tomography (2005)

Jeremy Pearce, Hyeokho Choi, Daniel M. Mittleman, Jeff White, David Zimdars

We describe a powerful imaging modality for terahertz (THz) radiation, THz wide aperture reflection tomography (WART). Edge maps of an object’s cross section are reconstructed from a series of...

Finite Impulse Response (2004)

Hyeokho Choi

A course on FIR filter design.

Forward: Fourier-wavelet regularized deconvolution for ill-conditioned systems (2004)

Ramesh Neelamani, Hyeokho Choi, Richard Baraniuk

We propose an efficient, hybrid Fourier-Wavelet Regularized Deconvolution (ForWaRD) al-gorithm that performs noise regularization via scalar shrinkage in both the Fourier and wavelet domains. The...

Forward: Fourier-wavelet regularized deconvolution for ill-conditioned systems (2004)

Ramesh Neelamani, Hyeokho Choi, Richard Baraniuk

Abstract—We propose an efficient, hybrid Fourier-wavelet regularized deconvolution (ForWaRD) algorithm that performs noise regularization via scalar shrinkage in both the Fourier and wavelet...

A Geometric Hidden Markov Tree Wavelet Model (2003)

Justin Romberg, Michael Wakin, Hyeokho Choi, Richard Baraniuk

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...

Geometric methods for wavelet-based image compression (2003)

Michael Wakin, Justin Romberg, Hyeokho Choi, Richard Baraniuk

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...

Rate-distortion optimized image compression using wedgelets (2002)

Michael Wakin, Justin Romberg, Hyeokho Choi, Richard Baraniuk

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...

Rate-distortion optimized image compression using wedgelets (2002)

Michael Wakin, Justin Romberg, Hyeokho Choi, Richard Baraniuk

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...

Multiscale image processing using normal triangulated meshes (2001)

Maarten Jansen, Hyeokho Choi, Sridhar Lavu, Richard Baraniuk

Multiresolution triangulation meshes are widely used in computer graphics for 3-d modeling of shapes. We propose an image representation and processing framework using a multiscale triangulation of...

Bayesian tree-structured image modeling using wavelet-domain hidden Markov models (2001)

Justin K. Romberg, Student Member, Hyeokho Choi, Richard G. Baraniuk, Senior Member

Abstract—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...

Bayesian tree-structured image modeling using wavelet-domain hidden Markov models (2001)

Justin K. Romberg, Hyeokho Choi, Richard G. Baraniuk

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...

Bayesian tree-structured image modeling using wavelet-domain hidden Markov models (2001)

Justin K. Romberg, Hyeokho Choi, Richard G. Baraniuk

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 density of...

Multiscale image segmentation using wavelet-domain hidden Markov models (2001)

Hyeokho Choi, Richard G. Baraniuk, Senior Member

Abstract—We introduce a new image texture segmentation algorithm, HMTseg, based on wavelets and the hidden Markov tree (HMT) model. The HMT is a tree-structured probabilistic graph that captures...

Multiscale SAR image segmentation using wavelet-domain hidden Markov tree models. Pages 110 120 of (2000)

Vidya Venkatachalam, Hyeokho Choi, Richard G. Baraniuk

We study the segmentation of SAR imagery using wavelet-domain Hidden Markov Tree (HMT) models. The HMT model is a tree-structured probabilistic graph that captures the statistical properties of the...

Hidden Markov Tree modeling of Complex Wavelet Transforms (2000)

Justin K. Romberg, Hyeokho Choi, Richard G. Baraniuk, Nick Kingsbury

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 coe#cients...

Multiscale document segmentation using wavelet-domain hidden Markov models (2000)

Hyeokho Choi, Richard Baraniuk

We introduce a new document image segmentation algorithm, HMTseg, based on wavelets and the hidden Markov tree (HMT) model. The HMT is a tree-structured probabilistic graph that captures the...

Multiscale image segmentation using joint texture and shape analysis (2000)

Ramesh Neelamani, Justin Romberg, Hyeokho Choi, Rudolf Riedi, Richard Baraniuk

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...

Edge localized image sharpening via reassignment with application to computer tomography (2000)

Timothy Dorney, Srikrishna Bhashyam, Andrew Doran, Hyeokho Choi, Patrick Fl, Richard Baraniuk

Traditional filtering methods operate on the entire signal or image. In some applications, however, errors are concentrated in specific regions or features. A prime example is images generated using...

Edge Localized Image Sharpening via Reassignment with Application to Computed Tomography (2000)

Timothy Dorney Srikrishna, Timothy Dorney, Srikrishna Bhashyam, Andrew Doran, Hyeokho Choi, Patrick Flandrin, ...

Traditional filtering methods operate on the entire signal or image. In some applications, however, errors are concentrated in specific regions or features. A prime example is images generated using...

Information-theoretic Interpretation of Besov Spaces (2000)

Hyeokho Choi, Richard Baraniuk

Besov spaces classify signals and images through the Besov norm, which is based on a deterministic smoothness measurement. Recently, we revealed the relationship between the Besov norm and the...

Multiscale SAR Image Segmentation using Wavelet-domain Hidden Markov Tree Models (2000)

Vidya Venkatachalam, Hyeokho Choi, Richard G. Baraniuk

We study the segmentation of SAR imagery using wavelet-domain Hidden Markov Tree (HMT) models. The HMT model is a tree-structured probabilistic graph that captures the statistical properties of the...

Multiscale Image Segmentation Using Joint Texture and Shape Analysis (2000)

Ramesh Neelamani, Justin Romberg, Hyeokho Choi, Rudolf Riedi, Richard Baraniuk

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...

Hidden Markov Tree modeling of Complex Wavelet Transforms (2000)

Hyeokho Choi, Justin Romberg, Richard Baraniuk

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...

Edge localized image sharpening via reassignment with application to computer tomography (2000)

Timothy Dorney, Srikrishna Bhashyam, Andrew Doran, Hyeokho Choi, Patrick Fl, Richard Baraniuk

Traditional filtering methods operate on the entire signal or image. In some applications, however, errors are concentrated in specific regions or features. A prime example is images generated using...

Wavelet-domain regularized deconvolution for ill-conditioned systems (1999)

Ramesh Neelamani, Hyeokho Choi, Richard Baraniuk

ABSTRACT by 0. In the discrete Fourier transform (DFT) domain, We propose a hybrid approach to wavelet-based im-age deconvolution that comprises Fourier-domain system inversion followed by...

Image segmentation using wavelet-domain classification (1999)

Hyeokho Choi, Richard Baraniuk

We introduce a new image texture segmentation algorithm, HMTseg, based on wavelet-domain hidden Markov tree (HMT) models. The HMT model is a tree-structured probabilistic graph that captures the...

Bayesian wavelet domain image modeling using hidden Markov trees (1999)

Justin K. Romberg, Hyeokho Choi, Richard G. Baraniuk

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...

Shift-invariant denoising using wavelet-domain hidden Markov trees (1999)

Justin K. Romberg, Hyeokho Choi, Richard G. Baraniuk

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...

Wavelet-Domain Regularized Deconvolution For Ill-Conditioned Systems (1999)

Ramesh Neelamani, Hyeokho Choi, Richard Baraniuk

We propose a hybrid approach to wavelet-based image deconvolution that comprises Fourier-domain system inversion followed by wavelet-domain noise suppression. In contrast to conventional...

Multiple Basis Wavelet Denoising Using Besov Projections (1999)

Hyeokho Choi, Richard Baraniuk

Wavelet-based image denoising algorithm depends upon the energy compaction property of wavelet transforms. However, for many real-world images, we cannot expect good energy compaction in a single...

Wavelet-Based Deconvolution for Ill-Conditioned Systems (1999)

Ramesh Neelamani, Hyeokho Choi, Richard Baraniuk, Corresponding Ramesh Neelamani

| We propose a hybrid approach to wavelet-based deconvolution that comprises Fourier-domain system inversion followed by wavelet-domain noise suppression. In contrast to other wavelet-based...

Wavelet-Based Deconvolution Using Optimally Regularized Inversion for Ill-Conditioned Systems (1999)

Ramesh Neelamani, Hyeokho Choi, Richard Baraniuk

We propose a hybrid approach to wavelet-based deconvolution that comprises Fourier-domain system inversion followed by wavelet-domain noise suppression. In contrast to conventional wavelet-based...

Wavelet-Based Deconvolution For Ill-Conditioned Systems (1999)

Ramesh Neelamani, Hyeokho Choi, Richard Baraniuk

In this paper, we propose a new approach to wavelet-based deconvolution. Roughly speaking, the algorithm comprises Fourierdomain system inversion followed by wavelet-domain noise suppression. Our...

Multiscale Image Segmentation using Wavelet-Domain Hidden Markov Models (1999)

Hyeokho Choi, Richard G. Baranuik

We introduce a new image texture segmentation algorithm, HMTseg, based on wavelets and the hidden Markov tree (HMT) model. The HMT is a tree-structured probabilistic graph that captures the...

Interpolation And Denoising Of Nonuniformly Sampled Data Using Wavelet-Domain Processing (1999)

Hyeokho Choi, Richard Baraniuk

In this paper, we link concepts from nonuniform sampling, smoothness function spaces, interpolation, and denoising to derive a suite of multiscale, maximum-smoothness interpolation algorithms. We...

Interpolation and denoising of nonuniformly sampled data using wavelet domain processing (1999)

Hyeokho Choi, Richard Baraniuk

In this paper, we link concepts from nonuniform sampling, smoothness function spaces, interpolation, and denoising to derive a suite of multiscale, maximum-smoothness interpolation algorithms. We...

Wavelet-based deconvolution for ill-conditioned systems (1999)

Ramesh Neelamani, Hyeokho Choi, Richard Baraniuk

In this paper, we propose a new approach to wavelet-based deconvolution. Roughly speaking, the algorithm comprises Fourierdomain system inversion followed by wavelet-domain noise suppression. Our...

Shift-invariant denoising using wavelet-domain hidden Markov trees (1999)

Justin K. Romberg, Hyeokho Choi, Richard G. Baraniuk

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...

Signal Processing Issues In Synthetic Aperture Radar And Computer Tomography (1998)

Hyeokho Choi, Hyeokho Choi, David C. Munson

This paper also proposed another reconstruction method based on a direct approximation of the Fourier inversion formula using a twodimensional (2-D) trapezoidal rule. In addition, the possibility of...

Direct-Fourier Reconstruction In Tomography And Synthetic Aperture Radar (1998)

Hyeokho Choi, David C. Munson

We investigate the use of direct-Fourier (DF) image reconstruction in computerized tomography and synthetic aperture radar (SAR). One of our aims is to determine why the convolutionbackprojection...

Multiscale Texture Segmentation using Wavelet-Domain Hidden Markov Models (1998)

Hyeokho Choi, Richard Baraniuk

Wavelet-domain Hidden Markov Tree (HMT) models are powerful tools for modeling the statistical properties of wavelet transforms. By characterizing the joint statistics of the wavelet coefficients,...

Analysis And Design Of Minimax-Optimal Interpolators (1998)

Hyeokho Choi, David C. Munson

We consider a class of interpolation algorithms, including the least-squares optimal Yen interpolator, and we derive a closed-form expression for the interpolation error for interpolators of this...

Analysis Of Wavelet-Domain Wiener Filters (1998)

Hyeokho Choi, Richard Baraniuk

We investigate Wiener filtering of wavelet coefficients for signal denoising. Empirically designed wavelet-domain Wiener filters have superior performance over other denoising algorithms using...

Analysis of wavelet domain Wiener filters (1998)

Hyeokho Choi, Richard Baraniuk

We investigate Wiener filtering of wavelet coefficients for signal denoising. Empirically designed wavelet-domain Wiener filters have superior performance over other denoising algorithms using...