Prof. David Luebke will be speaking on Monday at College Park.

			
		    THE FUTURE IS NOT FRAMED

		        Prof. David Luebke
		      University of Virginia
			
			Graphics Seminar 
		AVW 4424, 2:00pm, Monday, March 14
			

The ultimate display will not show "images". To drive the display of the
future, we must abandon our traditional concepts of pixels, and of images
as grids of coherent pixels, and of imagery as a sequence of images.

So what is this ultimate display? One thing is obvious: the display of
the future will have incredibly high resolution. A typical monitor today
has 100 dpiâ-far below a satisfactory printer. Several technologies offer
the prospect of much higher resolutions; even today you can buy a 300
dpi e-book. Accounting for hyperacuity, one can make the argument that a
"perfect" desktop-sized monitor would require about 6000 dpiâ-call it
11 gigapixels. Even if we don't seek a perfect monitor, we do want large
displays. The very walls of our offices should be active display surfaces,
addressable to a resolution comparable to or better than current monitors.

It's not just spatial resolution, either. We need higher temporal
resolution: hardcore gamers already use single buffering to reduce
delays. The human factors literature justifies this: even 15 ms of
delay can harm task performance. Exotic technologies (holographic,
autostereoscopic...) just increase the spatial, temporal, and directional
resolution required.

Suppose we settle for 1 gigapixel displays that can refresh at 240
Hzâ-roughly 4000x typical display bandwidths today. Recomputing and
refreshing every pixel every time is a Bad Idea, for power and thermal
reasons if nothing else.

I will present an alternative: discard the frame. Send the display
streams of samples (location+color) instead of sequences of images.
Build hardware into the display to buffer and reconstruct images from
these samples. Exploit temporal coherence: send samples less often
where imagery is changing slowly. Exploit spatial coherence: send fewer
samples where imagery is low-frequency. Without the rigid sampling
patterns of framed renderers,sampling and reconstruction can adapt with
very fine granularity to spatio-temporal image change.  Sampling uses
closed-loop feedback to guide sampling toward edges or motion in the
image. A temporally deep buffer stores all the samples created over a
short time interval for use in reconstruction.  Reconstruction responds
both to sampling density and spatio-temporal color gradients. I argue
that this will reduce bandwidth requirements by 1-2 orders of magnitude,
and show results from our preliminary experiments.

Biography: David Luebke is an Assistant Professor in the Department of
Computer Science at the University of Virginia. He earned his Ph.D. in
Computer Science at the University of North Carolina under Frederick
P. Brooks, Jr., and earned his Bachelors degree in Chemistry at the
Colorado College. Professor Luebke's principal research interest is
interactive computer graphics, particularly the problem of acquiring and
rendering very complex real-world scenes at interactive rates. Specific
projects include polygonal level of detail (LOD), temperature-aware
graphics architecture, scientific computation on graphics hardware,
advanced reflectance and illumination models for real-time rendering,
and image-based acquisition of real-world environments.  Funded by the
National Science Foundation, Professor Luebke and his students worked
with colleagues at the University of North Carolina to create the Virtual
Monticello museum exhibit. This exhibit ran for over 3 months and helped
attract over 110,000 visitors as a centerpiece of the major exhibition
Jefferson's America and Napoleon's France at the New Orleans Museum
of Art. Luebke is also a co-author of the book "Level of Detail for 3D
Graphics" with U. Maryland's own Amitabh Varshney.