Towards automatic photometric correction of casually illuminated documents

George V. Landon, Yun Lin, and W. Brent Seales. Towards automatic photometric correction of casually illuminated documents. 2007 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR 2007), 18-23 June 2007, Minneapolis, Minnesota, USA.

Abstract:
Creating uniform lighting for archival-quality document acquisition remains a non-trivial problem. We propose a novel method for automatic photometric correction of non-planar documents by estimating a single, point light-source using a simple light probe. By adding a simple piece of folded white paper with a known 3D surface to a scene, we are able to extract the 3D position of a light source, automatically perform white balance correction, and determine areas of poor illumination. Furthermore, this method is designed with the purpose of adding it to an already implemented document digitization pipeline. To justify our claims, we provide an accuracy analysis of our correction technique using simulated ground-truth data which allows individual sources of error to be determined and compared. These techniques are then applied on real documents that have been acquired using a 3D scanner.
article available here

Special issue on 3D acquisition technology for cultural heritage

Machine Vision and Applications has recently published a special issue on 3D acquisition for cultural heritage edited by Luc Van Gool and Robert Sablatnig.

Table of Contents:

1. Three-dimensional acquisition of large and detailed cultural heritage objects
• Gabriele Guidi, Bernard Frischer, Michele Russo, Alessandro Spinetti, Luca Carosso, and Laura Loredana Micoli
  
  
2. Petroglyph digitization: enabling cultural heritage scholarship
• George V. Landon and W. Brent Seales
  
  
3. A System for 3D Modeling Frescoed Historical Buildings with Multispectral Texture
• N. Brusco, S. Capeleto, M. Fedel, A. Paviotti, L. Poletto, G. M. Cortelazzo, and G. Tondello
  
  
4. Recent Developments in 3D Multi-modal Laser Imaging Applied to Cultural Heritage
• François Blais and J. Angelo Beraldin
  
  
5. Web-based 3D Reconstruction Service
• Maarten Vergauwen and Luc Van Gool

Petroglyph digitization: enabling cultural heritage scholarship

George V. Landon and W. Brent Seales, “Petroglyph digitization: enabling cultural heritage scholarship,” Machine Vision and Applications, vol. 17, no. 6, pp. 361–371, December 2006.

Abstract:
The digitization of antiquities is facilitating a renaissance for scholars who have unprecedented access to rich representations of objects. Cultural Heritage digitization is a central challenge, and its subtleties are intertwined with object properties and the constraints of physical access and handling. In this paper, we present the design and analysis of a system built for the digitization of Puerto Rican petroglyphic iconography. The petroglyphs exhibit unique properties (shape, size, surface) that determine system design choices. The 3D models obtained with the system support new scholarly and educational activities, including interactive surface lighting, feature highlighting and annotation through mark-up, and immersive viewing using large-scale displays.

Available Online

Computer Science & Illusion

As noted on Robert Burke's blog, Trinity College Dublin (TCD) recently hosted a great lecture by Prof. Andrew Blake. He really runs the gambit on topics in computer vision covering various theories and applications.

Part 1:


Part 2:

If you prefer not to stream: Full Movie Download (118MB WMV).
Also, the PowerPoint slides are available (44MB ZIPPED PPT).

Is Computer Science losing its coolness?

The Seattle Times has just run an interesting story, titled Where'd The Whiz Kids Go?, on the lack of CS students in Washington Universities. It seems that this is a nation-wide problem that has gotten big enough to get the attention of politicians.

From the article:

"... despite the seemingly limitless potential of computers, educators are having a tougher time than ever convincing students to pursue the field. It can be hard work. Boring, even. And there's that enduring, if unfair, image problem. Picture the socially inept geek hunched over a screen at 3 a.m., Coke in hand, pecking away at pages of incomprehensible code.

'There was such a boom of interest in the '90s, and now you get the sense around the country that computer science is past its prime. But the most exciting stuff is still in front of us.'

Meanwhile, Microsoft continues to add workers locally at the rate of 4,000 a year. In this year's record class of 5,400 UW freshmen, 300 say they're hoping to graduate in computer science or engineering. Even if none dropped out or changed majors, the class of 2010 wouldn't amount to a month's supply of new workers needed just at Microsoft's Redmond campus."

There certainly does not seem to be an easy solution to this shortage. It is also interesting to note that the ACT 2006 National Report shows that 2.05% of test takers are interested in at least a 4-year Computer Science or Math degree.

Interactive Tabletop Museum Exhibits

In the most recent issue of IEEE Computer Graphics and Applications, there is an interesting article titled "Interactive Tabletop Exhibits in Museums and Galleries."

From the article:

"The museum experience is an unusually tactile, sensual one, and the standard keyboard-mouse-and-screen setup might seem out of place. This trend toward sensual involvement is particularly noticeable in tabletop displays, as they appeal to two aspects of familiar daily life: the horizontal surface as a workspace, and hand gestures (or common objects) as tools for manipulating information."

The full article can be viewed online (PDF). Readers should notice that the article contains a nice sampling of various interactive/tabletop exhibits. The Tilty Table, in particular, demonstrates that interactivity and intuitive access can (and should) be combined in the museum experience. A sample video is available (MOV).

Smart Video Surveillance

The Journal News has conducted an interview with Arun Hampapur manager of IBM's Exploratory Computer Vision Group. The focus is mainly on how the 9/11/2001 attacks changed their research focus in computer vision.

From the Interview:

"Q:How did 9/11 affect your field?
A:Pre-9/11, the success stories in computer vision were around machine vision: How you inspect a printed circuit board while it is being manufactured. Now the biggest application of computer vision would be security. And there are two pieces to that security puzzle. Biometrics is answering the question, 'Who is this person?' Surveillance is answering the question, 'What is going on?'

Q:How does it work?
A:You can apply two kinds of functionality. One I called real-time alerts. You have a port and you have a fence, you don't want anyone jumping the fence. Or you have a retail store with a loading dock, and you don't want anyone on the loading dock past 9 o'clock. These are known conditions, for which you can say, 'OK, so if someone shows up on the loading dock after 9, tell me.'The second is being able to find things. Security is a kind of a cat-mouse game. Sometimes something becomes relevant only after the fact. If you remember the Washington sniper incident, somebody said there was a white van at the first scene, and then the police spent a lot of energy trying to look for the white van. There was no technology at that time which could use cameras to find white vans."

An overview (PDF) of this work has been published in IEEE Transactions on Signal Processing.