Ricardo Fabbri
Basic Info
- Full Professor & Head of VisLab at the Polytechnic Institute – IPRJ/UERJ, Brazil
- PhD in Computer Engineering from LEMS, Brown University, with prof. Ben Kimia
- Google, Inc. Book Search Team, Intern 2008, Full-time 2010
- Visual Computing Tech Lead & Founding Member of Lab Macambira hacker collective
- Curriculum Vitae: Lattes (portuguese), Google Scholar
Research abstract
My interests related to my PhD research deal with computer vision using multiple images of the same scene (as acquired by a camera in different positions, systems of multiple cameras, or video). This is useful for automating recognition, location, and measurement of 3D objects from images, 3D photography, etc. I am concerned with devising robust, precise and automatic methods for tackling problems in this area. In order to meet such requirements, I explore the use of grouped primitives such as curves and their differential geometry as the basis for the methods. I believe this is a much more powerful approach to solve multiview problems than the traditional one which relies on point primitives. I have been recently working on fusing a number of cues for 3D reconstruction. The end-goal is a system based on a hand-held video sequence, without need for calibration or textured regions, being able to identify not only the 3D structure of objects, but also the camera position, the reflectance properties, and lighting conditions as well. More information is provided in the following link:
Interests
- Computer Vision and Image Processing
- Automated 3D reconstruction from multiple views, camera auto-calibration, shape from shading
- Algorithms related to propagation and curve evolution: distance transforms, medial axes for shape representation, image segmentation, Voronoi diagrams, geodesics, shortest paths, inpainting
- Use of shape/context/geometric information in computer vision and machine learning
- Computational Geometry
- Applying Mathematics (esp. geometry) to computer vision and machine learning
- Differential Geometry, Singularity Theory
- Algebraic Geometry (solving systems of polynomial equations, projective geometry), Geometric Algebra
- Partial Differential Equations, specially geometric aspects
- Inverse problems connected to geometry
Publications
- R. Fabbri, P. J. Giblin, B. B. Kimia, "Camera Pose Estimation Using Curve Differential Geometry", IEEE ECCV 2012, Firenze, Italy (pdf | supplementary | code | bib) new!
- R. Fabbri, W. N. Goncalves, F. J. P. Lopes, O. M. Bruno "Multi-q pattern analysis: A case study in image classification", Physica A: Statistical Mechanics and its Applications, 2012, (pdf | bib) new!
- R. Fabbri and B. B. Kimia, "Multiview Differential Geometry of Curves", International Journal of Computer Vision, Dec 2010 (submitted), revisions under preparation. new!
- R. Fabbri, "Multiview Differential Geometry in Application to Computer Vision", Ph.D. Thesis, Division of Engineering, Brown University, 2010 (pdf | bib)
- J. C. Torelli, R. Fabbri, G. Travieso, O. M. Bruno "A high performance 3D exact Euclidean distance transform algorithm for distributed computing", International Journal of Pattern Recognition and Artificial Intelligence, 2010. (pdf | bib)
- R. Fabbri and B. B. Kimia "3D Curve Sketch: Flexible Curve-Based Stereo Reconstruction and Calibration", IEEE CVPR 2010. (pdf | poster | bib)
- R. Fabbri, L. da F. Costa, J. C. Torelli, O. M. Bruno, "2D Euclidean Distance Transform Algorithms: A Comparative
Survey", ACM Computing Surveys, Feb 2008. (pdf | bib | errata)
- Supplementary material and source code: distance.sf.net
-
R. Fabbri, B. B. Kimia, "High-Order Differential geometry of Curves for
Multiview Reconstruction and Matching", EMMCVPR 2005, Lecture Notes in Computer
Science, 3757, pp. 645-660, 2005. (original | corrected version)
- Theoretical paper on recovering torsion and curvature derivative of a space curve from multiple perspectives
- The formulas in the original paper have some minor imprecisions regarding the sign of the curvature. The corrected version fixes this issue.
- I wrote extensions of the formulas that take into account the intrinsic parameters. They show how the image point, tangent, curvature, and curvature derivative change under the transformation given by the intrinsic parameter matrix K.
- I implemented the formulas of this paper in a curve reconstruction system, just drop me an email and I will provide you with the code.
- R. Fabbri, L. F. Estrozi, L. da F. Costa, "On Voronoi Diagrams and Medial
Axes", Journal of Mathematical Imaging and Vision, 17(1), 27-40, july
2002.
- This was my first journal paper.
Software
-
Lab Macambira: an open
source development group. I am a founding member of this advanced software
engineering team in Brazil.
- VxL C++ Computer vision libraries. This is what we use here at Brown.
- SIP: Image processing toolbox for Scilab, similar to Matlab but with absolute freedom
- Hotreference.com: build your own searchable bibliography database online, with lots of storage space; Bibtex/doc export. Discuss you favorite paper with other users. All free (the site is by a very good friend of mine)
- Gentoo Linux: an excellent OS for computer scientists and experienced users.
Research and study material
- 3D Reconstruction from a Handheld camera: a project I coordinated as a TA.
- Summary of multiple view geometry as in Hartley's book (pdf | ppt)
- Summary of a recent paper in Auto-Calibration (pdf | odp)
- Obsolete Work Home Page
Teaching
- 2012/1
- Algorithm Design (undergraduate)
- Numerical Linear Algebra (undergraduate)
- Matrix Analysis (graduate)
- 2012/2
- Parallel Computing (graduate)
- Discrete Mathematics I(undergraduate)
- 2013/1
- Pattern Theory and Applications (graduate)
- Algorithm Design (undergraduate)
- Numerical Linear Algebra (undergraduate)
Photo album
Ask me by email for a username and password to access my album HERE
Curriculum Vitae
Lattes Platform, Google ScholarBlog
HereMy Social Network Profiles
Orkut | FacebookLinks
My brother's sonic compositions
Renato FabbriBeautiful Sea Shells
www.shellworldflkeys.comSome Comics and Animations by my Cousin and Friends
Pula Pirata WebsiteNo to Microsoft's OOXML/DOCX
www.noooxml.orgHome Pages of Other PhD Students at LEMS
Curiosities
Do the vertical borders of this page look strange to you? They are exactly the same gradients, reflected vertically. On their own, they should look convex or concave. But your brain is hypothesizing a global light source, and both bars can't be both convex and consistent with the same light source. There are also biases in direction - the brain tends to favor certain directions for the light source over others. As you might know, this is the convex concave crater illusion, and is related to the hollow-face illusion.