Xiaofeng Ren

Finding People in Archive Films through Tracking (2009)

Optical flow estimation requires spatial integration, which essentially poses a grouping question: what points belong to the same motion and what do not. Classical local approaches to optical flow,...

Tracking as Repeated Figure/Ground Segmentation (2009)

The goal of this work is to find all people in archive films. Challenges include low image quality, motion blur, partial occlusion, non-standard poses and crowded scenes. We base our approach on face...

Familiar configuration enables figure/ground assignment in natural scenes (2008)

Tracking over a long period of time is challenging as the appearance, shape and scale of the object in question may vary. We propose a paradigm of tracking by repeatedly segmenting figure from...

Vss Abstract, Xiaofeng Ren, Charless Fowlkes, Jitendra Malik

Figure/ground organization is a step of perceptual organization that assigns a contour to one of the two abutting regions. Peterson et al showed that familiar configurations of contours, such as...

Submission for IJCV Special Issue: Learning for Vision Learning Probabilistic Models for Contour Completion in Natural Images (2008)

7. Active Concept Learning for Image Retrieval in Dynamic Databases (2008)

Using a large set of human segmented natural images, we study the statistics of region boundaries. We observe several power law distributions which likely arise from both multi-scale structure within...

Maneesh Singh, Xiaofeng Ren, Yuri Boykov, Jing Zhong, Shuicheng Yan, Mingjing Li, ...

Nebojsa Jojic, Brendan Frey, Anitha Kannan. Pages 34–41. See the CD-ROM for a video of epitome learning and the epitome webpage for further examples, comparisons and software.

EXISTENCE AND STABILITY OF SPHERICALLY LAYERED SOLUTIONS OF THE DIBLOCK COPOLYMER EQUATION ∗ (2008)

MULTI-LAYER LOCAL MINIMUM SOLUTIONS OF THE BISTABLE EQUATION IN AN INFINITE TUBE (2008)

Abstract. The relatively simple Ohta–Kawasaki density functional theory for diblock copolymer melts allows us to construct and analyze exact solutions to the Euler–Lagrange equation by singular...

Oval shaped droplet solutions in the saturation process of some (2008)

Abstract. We construct local minimum solutions of the semilinear bistable equation by minimizing the corresponding functional near some approximate solutions, assuming that some global minimum...

Asymptotic Behavior of Energy Solutions to a Two Dimensional Semilinear Problem with Mixed Boundary Condition (2007)

pattern formation problems

On a Semilinear Elliptic Equation in R² when the Exponent Approaches Infinity (2007)

this paper we denote such least energy solutions by u p . Our goal here is to understand the asymptotic behavior of u p as p, serving as a parameter, approaches 1. It is known in [10] that for the...

Xiaofeng Ren, Juncheng Wei, The L

We consider a semilinear elliptic equation in R 2 with the nonlinear exponent approaching infinity. In contrast to the blow-up behavior of the corresponding problem in R n with n 3, the L 1 (R 2 )...

Multi-Layer Local Minimum Solutions Of The Bistable Equation In An Infinite Tube (2007)

Molecular Chirality and Soliton-Stripe Pattern in Liquid Crystal Films y (2007)

. We construct local minimum solutions of the semilinear bistable equation by minimizing the corresponding functional near some approximate solutions, assuming that some global minimum solutions are...

CS294-2 Markov Chain Monte Carlo: Foundations Applications Fall 2002 (2007)

The chiral liquid crystal film is a system of two coupled fields: A scalar field which represents the chirality of the molecules and a vector field which represents the direction of the molecules. In...

Lecturer Alistair, Sinclair Scribes, Yanlei Diao, Xiaofeng Ren

e Metropolis MC is reversible w.r.t. #(x) = w(x)/Z. Proof: Recall that a Markov Chain P is reversible w.r.t a probabilistic distribution q if #x, y q(x)P (x, y) = q(y)P (x, y). If x y, then both...

Abstract (2007)

Figure/ground assignment in natural images (2006)

solutions to a nonlocal free boundary problem from

Figure/Ground Assignment in Natural Images (2006)

Xiaofeng Ren Charless, Xiaofeng Ren, Charless C. Fowlkes, Jitendra Malik

Figure/ground assignment is a key step in perceptual organization which assigns contours to one of the two abutting regions, providing information about occlusion and allowing high-level processing...

Figure/ground assignment in natural images (2006)

Figure/ground assignment in natural images (2006)

Abstract. Figure/ground assignment is a key step in perceptual organization which assigns contours to one of the two abutting regions, providing information about occlusion and allowing high-level...

Wriggled lamellar solutions and their stability in the diblock copolymer problem. preprint (2005)

Abstract. Figure/ground assignment is a key step in perceptual organization which assigns contours to one of the two abutting regions, providing information about occlusion and allowing high-level...

In a diblock copolymer system the free energy field depends nonlocally on the monomer density field. In addition there are two positive parameters in the constitutive relation. One of them is small...

Mid-level cues improve boundary detection. Berkeley (2005)

We present a model of edge and region grouping using a conditional random field built over a scale-invariant representation of images to integrate multiple cues. Our model includes potentials that...

Xiaofeng Ren, Charless Fowlkes, Jitendra Malik

While mid-level perceptual cues have long been of interest in the human vision community, their role in computer vision has remained limited. In this report, we evaluate several algorithms which make...

Mid-level Cues Improve Boundary Detection (2005)

Xiaofeng Ren Charless, Xiaofeng Ren, Charless Fowlkes, Jitendra Malik

While mid-level perceptual cues have long been of interest in the human vision community, their role in computer vision has remained limited. In this report, we evaluate several algorithms which make...

We present a model of edge and region grouping using a conditional random field built over a scale-invariant representation of images to integrate multiple cues. Our model includes potentials that...

detection · Scale invariance · Conditional random fields · (2005)

We present a model of edge and region grouping using a conditional random field built over a scale-invariant representation of images to integrate multiple cues. Our model includes potentials that...

Xiaofeng Ren, Charless C. Fowlkes, Jitendra Malik, X. Ren, C. C. Fowlkes, J. Malik

Abstract Using a large set of human segmented natural images, we study the statistics of region boundaries. We observe several power law distributions which likely arise from both multi-scale...

Recovering human body configurations: Combining segmentation and recognition (2004)

We present a model of edge and region grouping using a conditional random field built over a scale-invariant representation of images to integrate multiple cues. Our model includes potentials that...

Greg Mori, Xiaofeng Ren, Alexei A. Efros, Jitendra Malik

localized joints and limbs. (c) Segmentation mask associated with human figure. The goal of this work is to take an image such as the one in Figure 1(a), detect a human figure, and localize his...

Recovering human body configurations: Combining segmentation and recognition (2004)

Greg Mori, Xiaofeng Ren, Alexei A. Efros, Jitendra Malik

localized joints and limbs. (c) Segmentation mask associated with human figure. The goal of this work is to take an image such as the one in Figure 1(a), detect a human figure, and localize his...

Recovering Human Body Configurations: Combining Segmentation and Recognition (2004)

Greg Mori, Xiaofeng Ren, Alexei A. Efros, Jitendra Malik

The goal of this work is to take an image such as the one in Figure 1(a), detect a human figure, and localize his joints and limbs (b) along with their associated pixel masks (c). In this work we...

Recovering Human Body Configurations: Combining Segmentation and Recognition (2004)

Greg Mori, Xiaofeng Ren, Alexei A. Efros, Jitendra Malik

The goal of this work is to take an image such as the one in Figure 1(a), detect a human figure, and localize his joints and limbs (b) along with their associated pixel masks (c). In this work we...

Learning a classification model for segmentation (2003)

Triblock copolymer theory: Ordered ABC lamellar phase (2003)

We propose a two-class classification model for grouping. Human segmented natural images are used as positive examples. Negative examples of grouping are constructed by randomly matching human...

On the Spectra of 3-D Lamellar Solutions of the Diblock Copolymer Problem (2003)

The ABC lamellar phase of a triblock copolymer in the strong segregation region is studied with the periodic and Neumann boundary conditions. In the periodic case we prove the existence of local...

Nucleation in the FitzHugh-Nagumo System: Interface-Spike Solutions (2003)

One-dimensional free energy local minimizers are viewed as three-dimensional lamellar type critical points in a box. To determine whether they model the lamellar phase of diblock copolymers in the...

Learning a Classification Model for Segmentation (2003)

We find nucleation solutions of N interfaces and K spikes to the one-dimensional FitzhHughNagumo system. Each spike sits asymptotically in the middle between two interfaces. We use the...

Xiaofeng Ren And, Xiaofeng Ren, Jitendra Malik

We propose a two-class classification model for grouping. Human segmented natural images are used as positive examples. Negative examples of grouping are constructed by randomly matching human...

Learning a classification model for segmentation (2003)

The nonlocal bistable equation: Stationary solutions on a bounded interval (2002)

We propose a two-class classification model for grouping. Human segmented natural images are used as positive examples. Negative examples of grouping are constructed by randomly matching human...

A probabilistic multi-scale model for contour completion based on image statistics (2002)

We discuss instability and existence issues for the nonlocal bistable equation. This model arises as the Euler-Lagrange equation of a nonlocal, van der Waals type functional. Taking the viewpoint of...

A probabilistic multi-scale model for contour completion based on image statistics (2002)

1 Introduction Traditionally there are two approaches to grouping: region-based methods and contour-based methods. Region-based approaches, such as the Normalized Cut framework [19], have been...

A Probabilistic Multi-Scale Model For Contour (2002)

We derive a probabilistic multi-scale model for contour completion based on image statistics. The boundaries of human segmented images are used as ”ground truth”. A probabilistic formulation of...

Completion Based On, Xiaofeng Ren, Jitendra Malik

We derive a probabilistic multi-scale model for contour completion based on image statistics. The boundaries of human segmented images are used as "ground truth". A probabilistic...

On the multiplicity of solutions of two nonlocal variational problems (2000)

Finite element analysis and design of a cantilever c-shape bimorph microactuator /--by Xiaofeng Ren. (1996)

We study two nonlocal variational problems in this paper. One models micro-phase separation of diblock copolymers and the other models solid-solid phase transformations that lead to fine structures....

Ren, Xiaofeng.

Thesis (M.S. in Mechanical and Industrial Engineering)--Louisiana Tech University, February 1996.

Variational Approach to Multiple Layers of the Bistable Equation in Long Tubes (1995)

Heteroclinic Orbits for a Higher Order Phase Transition Problem (1995)

Multiple layer solutions of the balanced bistable equation in infinite tubes are constructed via a variational method. I start with a characterization of Palais-Smale sequences which easily gives...

Peter W. Bates, Xiaofeng Ren

A standard model for one-dimensional phase profiles is the second order semilinear equation with bistable nonlinearity, where one seeks a solution which connects the two stable values. From a model...

Counting Peaks of Solutions to Some Quasilinear Elliptic Equations with Large Exponents (1995)

On A Two Dimensional Elliptic Problem With Large Exponent In Nonlinearity (1994)

We consider the asymptotic behavior of certain solutions to a quasilinear problem with large exponent in the nonlinearity. Starting with the investigation of a Sobolev embedding, we get a sharp...

A singular perturbation problem and its peaking solutions / (1994)

. A semilinear elliptic equation on a bounded domain in R 2 with large exponent in the nonlinear term is studied in this paper. We investigate positive solutions obtained by the variational method....

Ren, Xiaofeng.

Thesis (Ph.D.)--University of Minnesota, 1994.

Least-energy solutions to a non-autonomous semilinear problem with small diffusion coefficient (1993)

Least-energy Solutions to a Non-autonomous Semilinear Problem with Small Diffusion Coefficient (1993)

problem with a small diffusion coefficient are studied in this paper. We prove that the solutions will develop single peaks as the diffusion coefficient approaches 0. The location of the peaks is...

Least-energy Solutions to a Non-autonomous Semilinear Problem with Small Diffusion Coefficient (1993)

this paper we shall show that the least-energy solutions of (1.1) with either the Dirichlet boundary condition or the Neumann boundary condition develop spiky pattern of single peak as ffl approaches...