Schedule Tue 2:50-5:50 pm, Hill 482 Staff Instructor:  Prof. Doug DeCarlo Email: decarlo@cs Office: CoRE 310 Hours: Wed 2-4 pm Announcements Schedule Readings

Computer graphics is perhaps most often about making effective visual experiences. In these cases, the impression the viewer has of the display is paramount: the goal is to get the viewer to see what the display is designed to show them. It doesn't matter how the display is made - this is where cheating comes in: omission, distortion and exaggeration.

When we see a picture, we understand it, and our specific interpretation highlights particular information. What we see depends on what we're thinking and doing. Suppose you're driving to Times Square, following a map. What you're looking for is the route - the turnpike, to exit 16E, to the Lincoln tunnel. When you understand the map, what you have in your head is that same route. That's your interpretation of the map. We've all used computer systems that show you that route directly (and are accompanied by written instructions):

(Standard map from MapBlast)

(LineDrive map from MapBlast)

This seminar will make a case that we already have enough understanding of human visual perception and cognition to make good progress here. We'll look at work in computer graphics and human visual perception:

• Cartographic generalization
• Line drawings
• Detail modulation
• Exaggerated shading models
• Perception of materials
• Caricatures
• Stylized motion and "fake" physics

As for background, you should be comfortable with linear algebra and calculus, and should have taken a course in either computer graphics or computer vision (both aren't necessary).

There will be weekly readings.

You'll be expected to lead the discussion once during the semester, and there will be a course project/paper.

Audits are ok (email me), provided you participate regularly and lead the discussion once.

Jan 16

With the SIGGRAPH deadline approaching (Jan 26), I suspect many of you (I know of at least five, not counting myself) strongly prefer to skip the first two classes (Jan 18 and Jan 25). So let's do that. The first class is Feb 1. Please drop me an email if you're planning on attending but haven't registered. Note: If you're still deciding on whether you want to take this class, I will be there the first day for a half hour (Jan 18; 2:50-3:20) to give a brief overview and answer questions. Anything said there will be repeated on Feb 1. Thanks for your understanding!

Feb 1	Introduction
Feb 8	1.   Detail modulation and scale space	Anthony
Feb 15	2.   Caricature and `face space'	Chan-su, Oncel
Feb 22	3.   Map generalization	Andre, Nicu
Mar 1	4.   Ambiguity in perception: pictorial space	Andre, Smriti
Mar 22	5.    Exaggerated shading	Shin, Xiaofeng
Mar 29	6.    Line drawings	Tim, Xiaofeng
Apr 5	7.    Perception of materials	Smriti, Oncel
Apr 12	8.    Exaggerated Motion	Chan-su, Nicu
Apr 19	9.    Faking physics	Shin, Tim
Apr 26	Project day

Notes: I'm away March 8. March 15 is spring break.

The Photorealism exhibit at the Zimmerli.

1. Detail modulation and scale-space
   • Stylization and Abstraction of Photographs,
     Doug DeCarlo and Anthony Santella, SIGGRAPH 2002, 769-776.
     [Video: Quicktime MPEG]
   • Introduction to Scale-Space Theory: Multiscale Geometric Image Analysis,
     Bart M. ter Haar Romeny, Technical Report No. ICU-96-21, Utrecht Universit, 1996.
     (SKIP sections 4 and 7)

2. Caricature and `face space'
   • The caricature generator,
     S. Brennan, Leonardo, 18, 170-178, 1985.
   • Example-Based Caricature Generation with Exaggeration,
     L. Liang, H. Chen, Y. Xu, and H. Shum,
     Pacific Conference on Computer Graphics and Applications 2002, 386-393.
   • Linear Object Classes and Image Synthesis from a Single Example Image,
     T. Vetter and T. Poggio, PAMI, 19(7), 733-742, 1997.

   Optional reading:

   • Human Facial Illustrations: Creation and Psychophysical Evaluation,
     Bruce Gooch, Erik Reinhard, and Amy Gooch,
     ACM TOG, 23(1), January 2004, 27-44.
   • Improved Automatic Caricature by Feature Normalization and Exaggeration,
     Z. Mo, J.P. Lewis, and U. Neumann, SIGGRAPH 2003 Sketches and Applications.
   • The Fundamental Theorem of Linear Algebra,
     Gilbert Strang, American Mathematical Monthly, 100(9), 1993, 848-855.
     (A great description of SVD)

3. Map generalization
   • Chapter 24 of Elements of Cartography, 6th edition,
     A. Robinson, et al, Wiley 1995.
   • Rendering Effective Route Maps: Improving Usability Through Generalization,
     Maneesh Agrawala, Chris Stolte, SIGGRAPH 2001.
     (Try LineDrive directions at www.mapblast.com)

   Optional reading:

   • Automated Cartographic Map Generalization With Multiple Operators: A Simulated Annealing Approach,
     J. Mark Ware, Christopher B. Jones and Nathan Thomas,
     International Journal of Geographical Information Science 17(8), 743-769, 2003.
   • Section C (pp 126-136) in chapter 8 of Cartographic Relief Presentation,
     E. Imhof, de Gruyter 1982.
     
   ----

4. Ambiguity in perception: pictorial space
   • The visual perception of 3D shape,
     James T. Todd, Trends in Cognitive Science 8(3), 115-121, 2004.
   • The Bas-Relief Ambiguity,
     Peter N. Belhumeur, David J. Kriegman, and Alan L. Yuille,
     IJCV 35(1), 1999, 33-44.
   • Ambiguity and the `mental eye' in pictorial relief,
     J. J. Koenderink, A. J. van Doorn, A.M.L. Kappers, J.T. Todd,
     Perception, 30, 431-448, 2001.
     (In the news...)

5. Exaggerated shading
   • Cartoon-Looking Rendering of 3D-Scenes,
     Philippe Decaudin, INRIA Research Report #2919, June 1996.
     (Video is here.)
   • A Non-Photorealistic Lighting Model For Automatic Technical Illustration,
     Amy Gooch, Bruce Gooch, Peter Shirley, Elaine Cohen, SIGGRAPH 1998.
   • Hill shading and the reflectance map,
     B.K.P. Horn, Proceedings of the IEEE, 69(1), 14-47, 1981.

   Optional reading:

   • Conveying Shape and Features with Image-Based Relighting ,
     David Akers, Frank Losasso, Jeff Klingner, Maneesh Agrawala, John Rick, Pat Hanrahan,
     IEEE Visualization 2003.
     (Video and images are here).
     
   • Chapter 9 of Cartographic Relief Presentation,
     E. Imhof, de Gruyter 1982.
     (The classic. Warning: 94M file)

6. Line drawings
   • Suggestive Contours for Conveying Shape,
     Doug DeCarlo, Adam Finkelstein, Szymon Rusinkiewicz, and Anthony Santella,
     SIGGRAPH 2003, pp. 848-855.
     (Code is here.)
   • The shape of smooth objects and the way contours end,
     J. J. Koenderink and A. J. van Doorn, Perception, 11, 129-137, 1982.
   ----

7. Perception of materials
   • Real-world illumination and the perception of surface reflectance properties,
     Roland W. Fleming, R. O. Dror, and Edward H. Adelson,
     Journal of Vision, 3(5), 347-368, 2003.
   • Perceiving Translucent Materials,
     Roland W. Fleming, Henrik Wann Jensen, and Heinrich H. Buelthoff,
     First Symposium on Applied Perception in Graphics and Visualization, August 2004.

8. Exaggerated motion
   • Principles of traditional animation applied to 3D computer animation,
     John Lasseter, SIGGRAPH 1987, 35-44.
     (A web page containing a summary of this article.)
   • Turning to the Masters: Motion Capturing Cartoons,
     Chris Bregler, Lorie Loeb, Erika Chuang, Hrishi Deshpande,
     SIGGRAPH 2002, 399-407.
     (Video is here).
   • Stylizing Motion with Drawings,
     Y. Li, M. Gleicher, Y. Xu, and H. Shum,
     Proceedings of 2003 Symposium on Computer Animation

9. Faking physics
   • Faking Dynamics of Ropes and Springs,
     Ronen Barzel, IEEE Computer Graphics and Applications, 17(3), 31-39, 1997.
   • Sampling Plausible Solutions to Multi-Body Constraint Problems,
     Stephen Chenney and D. A. Forsyth, SIGGRAPH 2000.
     (Examples are here.)
   • Simulating Cartoon Style Animation,
     Stephen Chenney, Mark Pingel, Rob Iverson and Marcin Szymanski,
     NPAR 2002, pp 133-138.