Now showing items 1-20 of 71

    • 3-D Reconstruction of Shaded Objects from Multiple Images Under Unknown Illumination 

      Jin, Hailin; Wang, Dejun; Cremers, Daniel; Prados, Emmanuel; Yezzi, Anthony; Soatto, Stefano (Georgia Institute of TechnologySpringer Verlag, 2008-03)
      We propose a variational algorithm to jointly estimate the shape, albedo, and light configuration of a Lambertian scene from a collection of images taken from different vantage points. Our work can be thought of as extending ...
    • 3D Topology Preserving Flows for Viewpoint-Based Cortical Unfolding 

      Rocha, Kelvin R.; Sundaramoorthi, Ganesh; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2007-10)
      We present a variational method for unfolding of the cortex based on a user-chosen point of view as an alternative to more traditional global flattening methods, which incur more distortion around the region of interest. ...
    • 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 ...
    • Active Geodesics: Region based Active Contour Segmentation with a Global Edge based Constraint 

      Appia, Vikram; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2011-11)
      We present an active geodesic contour model in which we constrain the evolving active contour to be a geodesic with respect to a weighted edge-based energy through its entire evolution rather than just at its final state ...
    • 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 ...
    • Audio-Visual Flow - A Variational Approach to Multi-Modal Flow Estimation 

      Hamid, Raffay; Bobick, Aaron; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2004-10)
      Just as a motion field is associated to a moving object, an audio field can he associated to an object that can behave as a sound source. The flow field of such a sound source which moves over time would not only have an ...
    • Brain MRI T₁-Map and T₁-weighted Image Segmentation in a Variational Framework 

      Cheng, Ping-Feng; Steen, R.Grant; Yezzi, Anthony; Krim, Hamid (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2009-06)
      In this paper we propose a constrained version of Mumford- Shah’s[1] segmentationwith an information-theoretic point of view[2] in order to devise a systematic procedure to segment brain MRI data for two modalities of ...
    • Conformal Metrics and True "Gradient Flows" for Curves 

      Yezzi, Anthony; Mennucci, Andrea (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2005-10)
      We wish to endow the manifold M of smooth curves in Rn with a Riemannian metric that allows us to treat continuous morphs (homotopies) between two curves c0 and c1 as trajectories with computable lengths which are independent ...
    • Curious snakes: an active contour formulation of information-driven minimum-latency boundary detection 

      Soatto, Stefano; Sundaramoorthi, Ganesh; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2010-06)
      We present a region-based active contour detection algorithm for objects that exhibit relatively homogeneous photometric characteristics (e.g. smooth color or gray levels), embedded in complex background clutter. Current ...
    • 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 ...
    • 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 ...
    • Detection of curves with unknown endpoints using minimal path techniques 

      Kaul, Vivek; Tsai, Yichang; Yezzi, Anthony (Georgia Institute of TechnologyBMVA Press, 2010-09)
      We present a novel method to detect curves with unknown endpoints using minimal path techniques. Our work builds on the state of the art minimal path techniques currently used to detect curves. Existing algorithms in the ...
    • Fast Approximate Surface Evolution in Arbitrary Dimension 

      Malcolm, James; Rathi, Yogesh; Yezzi, Anthony; Tannenbaum, Allen (Georgia Institute of TechnologySociety of Photo-Optical Instrumentation Engineers, 2008)
      The level set method is a popular technique used in medical image segmentation; however, the numerics involved make its use cumbersome. This paper proposes an approximate level set scheme that removes much of the computational ...
    • Fast Mumford-Shah Segmentation using Image Scale Space Bases 

      Alvino, Christopher V.; Yezzi, Anthony (Georgia Institute of TechnologySociety of Photo-Optical Instrumentation Engineers, 2007)
      Image segmentation using the piecewise smooth variational model proposed by Mumford and Shah is both robust and computationally expensive. Fortunately, both the intermediate segmentations computed in the process of the ...
    • 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 ...
    • 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 ...
    • 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 ...
    • A Hybrid Medical Image Segmentation Approach Based on Dual-Front Evolution Model 

      Li, Hua; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2005-09)
      In this paper, a hybrid medical image segmentation approach is proposed based on a dual front evolution and fast sweeping evolution. This approach is composed of two stages. In the first stage, a fast sweeping evolution ...
    • Implicit Surface Segmentation by Minimal Paths: Applications in 3D Medical Images 

      Ardon, Roberto; Cohen, Laurent D.; Yezzi, Anthony (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2005-09)
      In this paper we introduce a novel edge-based, implicit approach for single object segmentation in 3D images. From a couple of curves, traced by the user on the object to be segmented, we implicitly generate a surface that ...
    • In-loop feature tracking for structure and motion with out-of-core optimization 

      Herrero, Nicolas; Landabaso, Jose-Luis; Gallego, Guillermo; Pujol-Alcolado, Jose-Carlos (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2010-09)
      In this paper, a novel and approach for obtaining 3D models from video sequences captured with hand-held cameras is addressed. We define a pipeline that robustly deals with different types of sequences and acquiring devices. ...