Pattern Theory Lunch Seminar Series

Brown University


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Upcoming Talks

October 7, 2015

12-1pm, 182 George St Room 110

Local Shape from Shading with a Generic Constraint

Ben Kunsberg

Prager Assistant Professor
Division of Applied Mathematics
Brown University

Humans have a remarkable ability to infer shape from shading (SFS) information. In computer vision this is often formulated with a Lambertian reflectance function, but it remains under-posed and incompletely solved. Abstractly, the intensity in an image is a single valued function and the goal is to uncover the vector valued normal function. This ill-posedness has resulted in many proposed techniques that are either regularizations or propagations from known values. Our goal is to understand, mathematically and computationally, how we solve this problem.

First, it has been shown psychophysically that our perception (via gauge figure estimates) is remarkably accurate even when the boundary is masked. Thus classical propagating approaches requiring a known values along a boundary, such as that of characteristic curves or fast marching methods, are unlikely to model the visual system's solution.

An alternative approach requires regularization priors (in a Bayesian framework) or energy terms (in a variational framework). However, many of the proposed priors are ad-hoc and chosen by researchers to optimize performance for a particular test dataset. It is hard to conclude (from solely performance metrics) whether these priors are useful or accurate, e.g. good results are functions of these priors, resolution, the optimization techniques, the test set, and so on.

In this talk, we describe a different approach. We consider the SFS problem on image patches modeled as Taylor polynomials of any order and seek to recover a solution for that patch. We build a boot-strapping tensor framework that allows us to relate a smooth image patch to all of the polynomial surface solutions (under any light source). We then use a generic constraint on the light source to restrict these solutions to a 2-D subspace, plus an unknown rotation matrix. We then investigate several special cases where the ambiguity reduces and the solution can be anchored. Interestingly, these anchor solutions relate to those situations in which human performance is also veridical.

[pizza will be provided]

Fall 2015 Schedule

Wednesdays, 12-1pm, 182 George St, Room 110 [lunch is provided]

September 9, 2015 ABSTRACT WEBSITE

Random matrix theory based analysis of the correlation structure of protein sequences

Lucy Colwell (Cambridge)

September 23, 2015 ABSTRACT WEBSITE

Continuum limit of total variation on point clouds

Nicolas Garcia-Trillos (Brown)

October 7, 2015 ABSTRACT WEBSITE

Local Shape from Shading with a Generic Constraint

Ben Kunsberg (Brown)

October 14, 2015 WEBSITE

Rachel Ward (UT Austin)

November 4, 2015 WEBSITE

David Jensen (UMass Amherst)

November 18, 2015 WEBSITE

Samuel Kou (Harvard)

December 2, 2015 WEBSITE

Constructing representations using Bayesian nonparametrics and connections between human knowledge, optimal foraging, and random walks on graphs

Joe Austerweil (Brown)

Spring 2016 Schedule

Wednesdays, 12-1pm, 182 George St, Room 110 [lunch is provided]

February 17, 2016 WEBSITE

Stefanie Jegelka (MIT)

March 2, 2016 WEBSITE

Facundo Memoli (Ohio State)

March 16, 2016 WEBSITE

Yali Amit (Chicago)

March 23, 2016 WEBSITE

Survey of Recent Neural Signal Processing Results

Emery Brown (MIT/Harvard)

2014-2015 Schedule


Two Recent Information Theoretic Variations on the Theme of Patterns in Security

Muriel Medard (MIT)


Adaptive Bayesian Estimation of Conditional Densities

Andriy Norets (Brown)


Using evolutionary sequence variation to make inferences about protein structure and function

Lucy Colwell (Cambridge)


From Pixels to Local Layers: Exploring Flexible Representations for Motion Estimation

Deqing Sun (Harvard)

February 25, 2015 ABSTRACT WEBSITE

Scaling and Generalizing Variational Inference

David Blei (Columbia)

February 4, 2015 ABSTRACT WEBSITE

Computational reconstruction and modeling of multicellular dynamics from 3D+time in vivo imaging of animal early embryogenesis. Extension to Artificial Life.

René Doursat (CNRS/Ecole Polytechnique, Paris)

December 3, 2014 ABSTRACT WEBSITE

Hypothesis-guided dimensionality reduction and its application to large-scale neuroscience

John Cunningham (Columbia)

Thursday, November 20, 2014 [4-5pm, Wilson 102] ABSTRACT WEBSITE

Joint Pattern Theory / LCDS Seminar

Geometric graph-based methods for high dimensional data

Andrea Bertozzi (UCLA)

November 12, 2014 ABSTRACT WEBSITE

Multiscale models for shapes and images

Pedro Felzenszwalb (Brown)

November 5, 2014 ABSTRACT WEBSITE

Cross-Study Validation versus Randomized Cross-Validation as Data Accumulate

Lo-Bin Chang (Johns Hopkins)

October 22, 2014 ABSTRACT WEBSITE

Algorithms for Interpretable Machine Learning

Cynthia Rudin (MIT)

October 8, 2014 ABSTRACT WEBSITE

A Simple Pattern-Theoretic Representation

Oren Freifeld (MIT)

October 1, 2014 ABSTRACT WEBSITE

Statistical mechanics for real biological networks

William Bialek (Princeton)

2013-2014 Schedule


Division of Applied Mathematics / Center for Vision Research Seminar

Computational Anatomy, High Throughput Neuro-Imaging Informatics, and the BrainCloud

Michael Miller (Johns Hopkins)


Climate informatics: Recent advances and challenge problems for machine learning in climate science

Claire Monteleoni (George Washington University)


The Blended Paradigm: A Bayesian approach to handling outliers and misspecified models

Steven MacEachern (Ohio State)


Division of Applied Mathematics / Center for Vision Research Seminar

The computational magic of the ventral stream: a theory (and why some deep architectures work)

Tomaso Poggio (MIT)


Can connectomics help us understand neural computation? Insights from the fly visual system

Dmitri Chklovskii (Janelia Farm)


Robust inference on parameters via particle filters and sandwich covariance matrices

Neil Shephard (Harvard)

February 26, 2014 ABSTRACT WEBSITE

Productivity and reuse in language: Non-parametric Bayesian models of lexical acquisition

Timothy O'Donnell (MIT)

February 12, 2014 ABSTRACT WEBSITE

Challenging issues in likelihood inference on mixture models

Daeyoung Kim (UMass Amherst)

December 4, 2013 ABSTRACT WEBSITE

Big data in neuroscience: Where is the information?

Joachim Buhmann (ETH Zurich)

November 20, 2013 ABSTRACT WEBSITE

Interactive Demonstrations in the Brown Robotics Lab [in CIT 134]

Chad Jenkins (Brown)

November 6, 2013 ABSTRACT WEBSITE

Dirichlet process mixture inconsistency for the number of components, and dimension mixture models

Jeffrey Miller (Brown)

October 23, 2013 ABSTRACT WEBSITE

High-dimensional statistics

Sahand Negahban (Yale)

October 9, 2013 ABSTRACT WEBSITE

Model selection in a large compositional space

Roger Grosse (MIT)

September 11, 2013 ABSTRACT WEBSITE

Parameter estimation robust to low-frequency contamination

Adam McCloskey (Brown)

2012-2013 Schedule

May 8, 2013 ABSTRACT

Scale-invariance and metrics on spaces of plane curves

Matt Feiszli


Towards a general theory of human learning and reasoning

Charles Kemp (Carnegie Mellon)


Encoding binary neural codes in networks of threshold-linear neurons

Carina Curto (Nebraska-Lincoln)


Learning to behave by reading

Regina Barzilay (MIT)


Sparse superposition codes: Communication by regression

Andrew Barron (Yale)

February 27, 2013 ABSTRACT WEBSITE

Bayesian model sampling in reinforcement learning

Michael Littman (Brown)

February 20, 2013 ABSTRACT WEBSITE

Nonstationary modeling through dimension expansion

Luke Bornn (Harvard)

January 30, 2013 ABSTRACT WEBSITE

Composite likelihood

Nancy Reid (Toronto)

November 14, 2012 ABSTRACT WEBSITE

Linking signaling pathways and dynamic regulatory networks

Anthony Gitter (Microsoft Research)

November 7, 2012 ABSTRACT WEBSITE

Natural image statistics and image restoration

Yair Weiss (Hebrew University)

October 24, 2012 ABSTRACT WEBSITE

Active learning under margin assumptions

Sivan Sabato (Microsoft Research)

October 3, 2012 ABSTRACT WEBSITE

Recovering large networks via optimizing non-likelihood functions

Rossi Luo (Brown)

2011-2012 Schedule


Division of Applied Mathematics / Center for Vision Research Seminar

Lessons from photographing and identifying the world's plant species

Peter Belhumeur (Columbia)

May 9, 2012 ABSTRACT

Computational challenges in molecular medicine

Donald Geman (Johns Hopkins)

April 25, 2012 ABSTRACT

Hallucinating scene detail and recognizing scene attributes

James Hays (Brown)

April 18, 2012 ABSTRACT

LP relaxations for global models in natural language processing

Sebastian Riedel (UMass)

March 28, 2012 ABSTRACT

What is the neural foundation of the vision process?

Christoph von der Malsburg (Frankfurt IAS)

March 21, 2012 ABSTRACT

The tree of life and the evolution of genome function

Casey Dunn (Brown)

February 8, 2012 ABSTRACT

Exploiting sparse structure by spectral connectivity analysis

Ann Lee (Carnegie Mellon)

February 1, 2012 ABSTRACT

Statistical analysis of populations with interacting and interfering units

Edo Airoldi (Harvard)

November 30, 2011 ABSTRACT

Exploring the role of ventral premotor cortex in reach-to-grasp movements: neural trajectories through spike train similarity space

Carlos Vargas-Irwin (Brown)

November 2, 2011 ABSTRACT

Perceptual Fragments: Bottom-Up and Top-Down Use of Shape in Object Recognition

Benjamin Kimia (Brown)

October 19, 2011 ABSTRACT

Statistical challenges in neural data analysis

Liam Paninski (Columbia)

October 12, 2011 ABSTRACT

Spectral Methods for Learning Graphical Models

Sham Kakade (UPenn & MRNE)

October 5, 2011 ABSTRACT

Dynamic regulation of decision threshold by frontal cortex and basal ganglia

Michael Frank (Brown)

September 14, 2011 ABSTRACT

Non-parametric Priors for Segmentation of Medical Images

Polina Golland (MIT)

2010-2011 Schedule

May 11, 2011 ABSTRACT

Division of Applied Mathematics / Center for Vision Research Seminar

Statistical structures of natural scenes and neural ensembles activities

Tai Sing Lee (Carnegie Mellon)

May 4, 2011 ABSTRACT

Logistic Regression on Data Streams

Kevin Kochanek (US Department of Defense)

April 20, 2011 ABSTRACT

Self-folding of polyhedra-- experiments and a little theory

Govind Menon (Brown)

April 6, 2011 ABSTRACT

Division of Applied Mathematics / Center for Vision Research Seminar

A High-Throughput Screening Approach to Biologically-Inspired Object Recognition

David Cox (Rowland Institute at Harvard)

March 16, 2011 ABSTRACT

Solving Inference, Optimization, and Constraint Satisfaction Problems with the Divide & Concur and Belief Propagation Message-Passing Algorithms

Jonathan Yedidia (MERL)

March 9, 2011 ABSTRACT

A history of applying principal component analyses to human population genetic data

Sohini Ramachandran (Brown)

February 16, 2011 ABSTRACT

Patterns of Thought (in humanoid robots)

Yiannis Aloimonos (University of Maryland)

February 9, 2011 ABSTRACT

Division of Applied Mathematics / Center for Vision Research Seminar

Learning on Analytic Manifolds

Fatih Porikli (MERL)

November 17, 2010 ABSTRACT

Point process adaptive filters and the analysis of ensemble neural spiking activity

Uri Eden (Boston University)

November 3, 2010 ABSTRACT

Bottom-up and top-down processing in visual perception

Thomas Serre (Brown)

October 20, 2010 ABSTRACT

Discovering Influential Variables: A Partition Retention Approach

Herman Chernoff (Harvard)

October 6, 2010 ABSTRACT

(CIT 241, Swig Boardroom)

Learning Probabilistic Models with Deep Hierarchical Structures

Ruslan Salakhutdinov (MIT)

2009-2010 Schedule

May 10, 2010 ABSTRACT

Shared Segmentation of Natural Scenes using Dependent Pitman-Yor Processes

Erik Sudderth (Brown)

April 23, 2010 ABSTRACT

A Generative Model Approach to Fraud Detection

Brian Lucena (Guardian Analytics, Inc.)

April 21, 2010 ABSTRACT

Segmentation of Image Ensembles via Latent Atlases

Tammy Riklin-Raviv (MIT)

April 16, 2010 ABSTRACT

Applied Mathematics / Center for Statistical Sciences Seminar

Multi-Resolution Inference of Stochastic Models from Partially Observed Data

Samuel Kou (Harvard)

April 14, 2010 ABSTRACT

Preserving knowledge through media transitions: ushering the heritage of India into the digital age

Peter Scharf (Brown)

April 9, 2010 ABSTRACT

Analysis of Molecular Networks

Mark Gerstein (Yale)

April 7, 2010 ABSTRACT

Geometry of the space of 2D shapes equipped with the Weil-Petersson metric

Sergey Kushnarev (Brown)

March 24, 2010 ABSTRACT

Unsupervised Part of Speech Tagging: From graphical models to statistical models to "biological" models

Michael Lamar (Brown)

March 17, 2010 ABSTRACT

Learning in Social Networks with Signals of Bounded Informativeness

Ilan Lobel (Microsoft Research New England)

March 12, 2010 ABSTRACT

Graphs and polytopes: learning structures with linear programming relaxations

Tommi Jaakkola (MIT)

March 10, 2010 ABSTRACT

Respondent-Driven Sampling for Networks: Degrees of Uncertainty with Uncertain Degrees

Joe Blitzstein (Harvard)

March 3, 2010 ABSTRACT

Topic Models: Priors, Stop Words and Languages

Hanna Wallach (UMass)

February 17, 2010 ABSTRACT

Message Passing Algorithms for Compressed Sensing

Andrea Montanari (Stanford)

February 12, 2010 ABSTRACT

Applied Mathematics / Center for Vision Research Seminar

Learning Hierarchies of Sparse Visual Features

Yann LeCun (Courant)

February 3, 2010 ABSTRACT

An analysis of connectivity in neuronal population recordings

Asohan Amarasingham (Rutgers)

November 20, 2009 ABSTRACT

Applied Mathematics / Center for Statistical Sciences Seminar

Error controls for multiple hypothesis testing

Zhiyi Chi (U Conn)

November 18, 2009 ABSTRACT

Spectral Filtering Approaches to Machine Learning

Lorenzo Rosasco (MIT)

November 11, 2009 ABSTRACT

Generative Models for Image Analysis

Lo-Bin Chang (Brown)

November 6, 2009 ABSTRACT

Applied Mathematics / Center for Vision Research Seminar

Understanding Visual Scenes

Antonio Torralba (MIT)

November 2, 2009 ABSTRACT

Center for Statistical Sciences / Applied Mathematics Seminar

Application of Heteroskedastic Spatial Models to Computer Experiments

Richard A. Davis (Columbia)

October 28, 2009 ABSTRACT

Statistical Analysis of Climate Ecosystem Dynamics

Surajit Ray (Boston University)

October 21, 2009 ABSTRACT

Recent Advances on the Geometry of the Riemannian Manifold of Landmarks

Mario Micheli (UCLA)

October 14, 2009 ABSTRACT

SIFT Flow: Dense Scene Alignment and Its Applications

Ce Liu (Microsoft Research New England)

October 7, 2009 ABSTRACT

The probabilistic language of thought

Noah Goodman (MIT)

September 30, 2009 ABSTRACT

Learning maximum-entropy models of salience via EM

Micha Elsner (Brown)

September 23, 2009 ABSTRACT

Latent Socio-Spatial Process Model for Social Networks

Crystal Linkletter (Brown)

September 16, 2009 ABSTRACT

Organizational meeting & Conditional inference for non-stationary data

Matthew Harrison (Brown)