Images and Image-Based
By Hal Newnan
17 August 2001 Friday, West Hall A
Chair: Brian A. Barsky, University of California, Berkeley
Image-Based Motion Blur for Stop Motion Animation
Gabriel J. Brostow, Irfan Essa, Georgia Institute of Technology
Animation, Applications, Computer Vision, Image Processing, Image-Based
Rendering, Object Tracking, and Video
Brostow speaks of being able to segment pixels that are moving from
one image to the next, blurring these, and leaving the pixels that
are not changing unscathed. This is a major improvement over older
methods, as seen in the demo video.
A Simple and Efficient Error-Diffusion Algorithm
Victor Ostromoukhov, Universite de Montreal
Keywords: Halftoning and Dithering
Ostromoukhov speaks of "Halftoning" as basic but important,
and of the "Floyd-Steinberg E-D" as obsolete. He answers
the question "What is halftoning?" with: "a method
of producing an illusion (dithering) of smoothness." By audience
response Ostromoukhov's offering is the "best of class"
for this session.
His solution offers visual quality, excellent speed, conceptual
simplicity and legal availability (i.e. all of the criterion needed)
in visual quality for low -res displays. The DBS-based Algorithm
is still the best for quality but it is slow and complex. Our solution
verges on the best quality but is quick, easy, and FREE. All the
documentation is available to you for download at http://www.iro.umontreal.ca/~ostrom/.
Alejo Hausner, University of Toronto
Keywords: Computational Geometry, Frame Buffer Algorithms, Non-Realistic
Rendering, Paint Systems, Scientific Visualization
Hausner says that his topic is pointing in the opposite way from
Ostromoukhov's, because he is looking to emphasize the visual artifacts
(albeit in a highly organized way). Decorative Mosaics are among
the most long-lasting graphics to be found, and usually graphics
are disposable items.
Pixels have orientation, and Hausner suggests that they were developed
three thousand years ago as tiles, and that edges are visually important
in mosaics. His scientific discussion unfurls around the use of
Centroidal Voronoi Diagrams (or CVDs). CVDs after convergence appear
as a honeycomb shape that is associated with minimum energy arrangements.
Key idea 1: CVDs and tilings use best circle packing, and that equals
hexagonal tiling. Key idea 2: Why Cones? It is a plot of a distance
function for a Manhattan Metric as a square cone (a pyramid).
This is an effective way to make mosaics of any 2D image.
Emil Praun, Matthew Webb, Adam Finkelstein all of Princeton University
Hugues Hoppe of Microsoft Research
Keywords: Animation Systems, Frame Buffer Algorithms, Nonrealistic
Rendering, Texture Mapping, Automatic Indication
This is a way to apply a non-realistic style that will be consistent
through multiple frames, and is therefore suitable for use in animation.
The last paper
they keep one of the very best papers for the very last paper
of the very last session.
This year it
was Real-Time Hatching. It was a blend of NPR, IBR, etc...
topic of pattern indication will be worth several papers.
Indication is giving an indication of what the pattern should
be while at the same time removing clutter from areas where
our minds will fill in the pattern automatically.