Now showing items 1-20 of 106

    • Gradient flows and geometric active contour models 

      Kichenassamy, Satyanad; Kumar, Arun; Olver, Peter; Tannenbaum, Allen R.; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1995-06)
      In this paper, we analyze the geometric active contour models discussed previously from a curve evolution point of view and propose some modifications based on gradient flows relative to certain new feature-based Riemannian ...
    • Active contours for visual tracking: a geometric gradient based approach 

      Kumar, Arun; Yezzi, Anthony; Kichenassamy, Satyanad; Olver, Peter; Tannenbaum, Allen R. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1995-12)
      In this note, we analyze the geometric active contour models proposed in [5, 191 from a curve evolution point of view and propose some modifications based on gradient flows relative to certain new metrics. This leads to a ...
    • Phase transitions, curve evolution, and the control of semiconductor manufacturing processes 

      Berg, Jordan M.; Yezzi, Anthony; Tannenbaum, Allen R. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1996-12)
      This paper presents a strategy for the estimation and control of certain semiconductor manufacturing processes, employing models developed to describe the dynamics of material interfaces in phase transition problems. ...
    • A Geometric Snake Model for Segmentation of Medical Imagery 

      Yezzi, Anthony; Kichenassamy, Satyanad; Kumar, Arun; Olver, Peter; Tannenbaum, Allen R. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1997-04)
      We employ the new geometric active contour models, previously formulated, for edge detection and segmentation of magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound medical imagery. Our method is ...
    • Toward real-time estimation of surface evolution in plasma etching: isotropy, anisotropy, and self-calibration 

      Berg, Jordan M.; Yezzi, Anthony; Tannenbaum, Allen R. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1997-12)
      Level set methods are proving to be an effective tool for simulating surface evolution during chip manufacturing processes such as etching, deposition, and lithographic development. These methods can be implemented using ...
    • Modified curvature motion for image smoothing and enhancement 

      Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1998-03)
      In this paper, we formulate a general modified mean curvature based equation for image smoothing and enhancement. The key idea is to consider the image as a graph in some Rn, and apply a mean curvature type motion to the ...
    • Projected Mean Curvature Smoothing for Vector-Valued Imagery 

      Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1998-04)
      In this note, we formulate a general modified mean curvature based equation for image smoothing and enhancement. The key idea is to consider the image as a graph in some Rⁿ, and apply a mean curvature type motion to the ...
    • Curve Evolution Models for Real-Time Identification with Application to Plasma Etching 

      Berg, Jordan M.; Yezzi, Anthony; Tannenbaum, Allen R. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1999-01)
      It is desirable, in constructing an algorithm for real-time control or identification of free surfaces, to avoid representations of the surface requiring mesh refinement at corners or special logic for topological transitions. ...
    • A Statistical Approach to Snakes for Bimodal and Trimodal Imagery 

      Yezzi, Anthony; Tsai, Andy; Willsky, Alan (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 1999-09)
      In this paper, we describe a new region-based approach to active contours for segmenting images com- posed of two or three types of regions characterizable by a given statistic. The essential idea is to derive curve evolutions ...
    • Fusion of Visible and X-Ray Sensing Modalities for the Enhancement of Bone Detection in Poultry Products 

      Vachtsevanos, George; Daley, Wayne D.; Heck, Bonnie S.; Yezzi, Anthony; Ding, Yuhua (Georgia Institute of TechnologySociety of Photo-Optical Instrumentation Engineers, 2000)
      The U.S. demand for deboned chicken has risen greatly in the past 5 years, with the expectations that this demand will oniy continue at an accelerated level. The standard inspection process for bones in meat is for workers ...
    • Medical Image Segmentation via Coupled Curve Evolution Equations with Global Constraints 

      Yezzi, Anthony; Tsai, Andy; Willsky, Alan (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2000-06)
      In this work we modify the couple d curve evolution approach to snakes presented by the authors in previous work for bimodal and trimodal imagery through the introduction of global constraints. The key idea, as before, ...
    • A Stochastic Flow for Feature Extraction 

      Unal, Gozde; Krim, Hamid; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2000-06)
      In recent years evolution of level sets of two-dimensional functions or images in time through a partial differential equation has emerged as an important tool in image processing. Curve evolutions, which may be viewed ...
    • A curve evolution approach to smoothing and segmentation using the Mumford-Shah functional 

      Tsai, Andy; Yezzi, Anthony; Willsky, Alan S. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2000-06)
      In this work, we approach the classic Mumford-Shah problem from a curve evolution perspective. In particular we let a given family of curves define the boundaries between regions in an image within which the data are modeled ...
    • Stereoscopic Shading: Integrating Multi-Frame Shape Cues in a Variational Framework 

      Jin, Hailin; Yezzi, Anthony; Soatto, Stefano (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2000-06)
      We address the problem of integrating multi-frame stereo and shading cues within the framework of optimization in the infinite-dimensional space of piecewise smooth surfaces. Cue integration then reduces to the determination ...
    • Curve Evolution, Boundary-Value Stochastic Processes, the Mumford-Shah Problem, and Missing Data Applications 

      Tsai, Andy; Yezzi, Anthony; Willsky, Alan S. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2000-09)
      We present an estimation-theoretic approach to curve evolution for the Mumford-Shah problem. By viewing an active contour as the set of discontinuities in the Mumford-Shah problem, we may use the corresponding functional ...
    • Feature-Preserving Flows: A Stochastic Differential Equation's View 

      Unal, Gozde; Krim, Hamid; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2000-09)
      Evolution equations have proven to be useful in tracking fine to coarse features in a single level curve and/or in an im- age. In this paper, we give a stochastic insight to a specific evolution equation, namely the geometric ...
    • A Summary of Geometric Level-Set Analogues for a General Class of Parametric Active Contour and Surface Models 

      Xu, Chenyang; Yezzi, Anthony; Prince, Jerry L. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2001)
      Geometric active contours (GACs) and surfaces (GASs) implemented via level set techniques enjoy many advantages over parametric active contours (PACs) and surfaces (PASs), such as computational stability and the ability ...
    • Stereoscopic Segmentation 

      Yezzi, Anthony; Soatto, Stefano (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2001-07)
      We cast the problem of multiframe stereo reconstruction of a smooth shape as the global region segmentation of a collection of images of the scene. Dually, the problem of segmenting multiple calibrated images of an ...
    • Curve evolution implementation of the Mumford-Shah functional for image segmentation, denoising, interpolation, and magnification 

      Tsai, Andy; Yezzi, Anthony; Willsky, Alan S. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2001-08)
      In this work, we first address the problem of simultaneous image segmentation and smoothing by approaching the Mumford–Shah paradigm from a curve evolution perspective. In particular, we let a set of deformable contours ...
    • Anti-Geometric Diffusion for Adaptive Thresholding and Segmentation 

      Manay, Siddharth; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2001-10)
      In this paper, we present a novel adaptive thresholding technique based upon an anisotropic diffusion model, which may be referred to as the anti-geometric heat flow. In contrast to its more popular counterparts (such as ...