From: steve1@cc.gatech.edu (Steve Adelson)
Newsgroups: misc.jobs.resumes
Subject: PhD. Computer Graphics seeks research position in Pacific NW
Date: 5 Nov 92 13:48:15 GMT
Distribution: usa
Organization: Software Research Center, Georgia Tech

Stephen J. Adelson
311 Valley Brook Crossing
Decatur, GA 30033-5847
404-299-6012

November 5, 1992

Dear Prospective Employer:

 	I am a graduate student at the Georgia Institute of Technology in 
Atlanta, Georgia.  I am studying computer graphics algorithms, and will 
be graduating in June 1993 with a Ph.D. in computer science.

	I am seeking employment in the Pacific Northwest researching graphics 
algorithms and virtual environments.  I have been involved for over three years 
in research concerning efficient stereoscopic display algorithms and 
interaction with virtual environments, as well as some studies in the human 
factors concerns of stereoscopic viewing of computer generated images. 

	I desire further challenges in defining and implementing computer 
graphics algorithms, and an opportunity to examine the many unresearched topics
in virtual environments presently assumed to be identical with CRT-based 
displays.  I would be happy to discuss my qualifications with you at any time.  
I look forward to your reply.


						Sincerely,

						Stephen J. Adelson

--------------------------------------------------------------------------------

                               STEPHEN J. ADELSON

                            311 Valley Brook Crossing
                           Decatur, Georgia 30033-5847
                      H: (404) 299-6012  W: (404) 853-9389
                           email: steve1@cc.gatech.edu


EDUCATION

Ph.D. Computer Science   	      June 1993  Georgia Institute of Technology
M.S.  Information and Computer Science  1989	 Georgia Institute of Technology
B.S.  Mathematics / Computer Science	1988	 Emory University
B.A.  Economics				1988	 Emory University
	GPA: 3.8/4.0


AWARDS AND HONORS

National Merit Scholar				1984-1988
Dean's List, all semesters			1984-1988
Member, Society for Collegiate Journalists	1987
Member, ODE, national economics honor society	1987
Member, Phi Beta Kappa				1987
President's Fellow				1988-1992
Research image chosen as Georgia Tech 
	College of Computing Recruiting Poster	1991
Research image to be used in Georgia Tech
 	Recruiting Calendar			1993


EXPERIENCE

9-12/90, 4/91- present   	                              Teaching Assistant
								    Georgia Tech
In addition to teaching class, duties also included preparing notes, quizzes, 
and tests; providing tutorial help when needed; and evaluating student projects 
and tests.  Assisted courses include Databases, Introduction to Computer 
Graphics, Three-dimensional computer graphics, and Advanced Topics in Computer 
Graphics.

1-3/91					                       NSF Crane Project
								    Georgia Tech
Created basic model and interface tools for a nationally funded project.  Model 
and tools were used for perceptual experiments involving stereoscopic vision as 
well as used for a automated construction sight model.

1-9/89								   SPOCK Project
								    Georgia Tech
Worked with design team on user interface for experimental computer.

5-7/87, 1-8/88					     		      Programmer
					    Physics Department, Emory University
Responsible for programming PC and Apple II computers for experimental data 
gathering and analysis.  Designed and implemented user interface and graphical 
output on PC for automated superconductor experiments.


RESEARCH INTERESTS

Three-dimensional computer graphics display algorithms, efficient animation 
frame generation, virtual environments.


When generating stereoscopic images for scientific visualization, virtual 
environments, or other applications, it is common practice to treat each eye as 
a separate viewpoint, doubling the work required to generate the view.  Yet each
eye sees almost the exact same image.  It is possible to use the geometry of the
viewing positions to reuse many of the pixels from one half of the pair to help 
create the second half, thereby saving 50% or more of the computational time of 
generating the second half.  Similarly, in two consecutive animation frames many
of the same pixels coexist, although in different positions.  The stereoscopic 
savings technique can be generalized to realize significant savings in computer 
generated animations.

By using reprojection, or moving pixels horizontally based upon the z position 
of the projecting point and the value of the interoccular distance (e), I have 
demonstrated savings in creating the second half of a stereoscopic pair.  
Specifically, I have shown savings in interpolating pixels (with and without 
Gouraud shading), line clipping, hidden surface elimination, and ray-tracing 
(visible surface and full ray tracing).  Depending on the application and the 
complexity of the image, we can save up to 95% of the computing time required to
create the second half of the stereoscopic pair.  Further, I have shown that 
stereoscopic ray-tracing will never be as inefficient as two passes of a 
standard ray-tracer, regardless of the complexity of the image rendered.

I am extending the reprojection technique into generating ray-traced animations 
in which the objects in the scene do not move.  Almost all the pixels in one 
half of a stereoscopic pair exist in the other half.   The same will be true for
two animation frames.  Therefore, stereoscopic ray-tracing is a special case of 
the general animation frame generation technique I will describe momentarily, 
and reprojection is a specialized version of re-using pixels given the 
particular geometry of the stereoscopic image.  

Rather than make the reprojection technique more complex to take into account 
the general movement and rotation, I have found that it is far more efficient to
take the three dimensional points in the previous view, rotate and translate 
them to the next position, and project them to their new positions on the 
screen.  We save to disk the three-dimensional point seen in each pixel.  By 
testing if the projected point lies within the viewing volume of the previous 
position, I can take into account objects entering the scene due to a camera 
movement.  This problem is unsolved with a generalized scan-line reprojection 
method.

One of the advantages of this method is that we may now process pixels in any 
order and, what is more important, we can save the pixels to disk in any order. 
This process allows for any movement and rotation of the viewpoint.  Further, 
since we are saving the three-dimensional points rather than the projected 
position, errors in the image do not compound.  Every pixel seen in the image is
off from its exact position by no more than 1/2 of a pixel.  The errors get 
smaller when we use the adaptive super-sampling scheme profiled in Stereoscopic 
Ray-Tracing.  With two possible levels of ray-tracing, each projected point is 
off by less than 1/4 of a pixel; at three levels, by less than 1/8 of a pixel.

The method appears to operate successfully on images I create, with a 33% speed 
up for a simple 20 object scene.  This percentage will increase for more complex
images, since the reusing of pixels will depend upon the number of pixels in the
image, not the number of objects in the rendered scene.


PUBLICATIONS

"Efficient Generation of Stereoscopic Images and Extensions to Animation Frames"
S.J. Adelson, Ph.D. thesis.

"Stereoscopic Ray-Tracing," S.J. Adelson and L.F. Hodges.  Georgia Tech TR 
GIT-GVU-92-17.  To appear in _The_Visual_Computer_.

"Performance Comparison of Multiple Image Depth and Shape Cues," S.J. Adelson, 
J. Allen, A.N. Badre, L.F. Hodges, and A. Lawrence.  Georgia Tech TR 
GIT-GVU-91-15.  To appear in _The_International_Journal_of_Human_Computer_
Interaction_.

Research image, "3D Buzz", included in SIGGRAPH Stereoscopic Slide Set (images 
01 and 02), 1992

"Visible Surface Ray-Tracing of Stereoscopic Images," S.J. Adelson and L.F. 
Hodges.  Proceedings of the 30th Annual Meeting of the SE ACM (April 1992), 148-
157.

"Simultaneous Generation of Stereoscopic Views," S.J. Adelson, J.B. Bentley, 
I.S. Chong, L.F. Hodges, and J. Winograd.  _Computer_Graphics_Forum:_Journal_of_
the_European_Association_for_Computer_Graphics_, vol. 10, 1 (March 1991), 3-10.

"Comparison of 3-D Display and Depth Enhancement Techniques," S.J. Adelson, 
A. Badre, L.F. Hodges, and A. Lunde.  _Proceedings_of_the_Society_for_
Information_Display_, vol. 32, 1 (January 1991), 25-30.

"Comparison of Different 3D and Depth Enhancement Display Techniques for 
Determination of Shape and Relative Position," S.J. Adelson, A. Badre, L.F. 
Hodges, and A. Lunde.  1990 International Symposium of the Society for 
Information Display Digest of Technical Papers, vol. 21 (1990), 351-354.


PRESENTATIONS

"Comparison of Different 3D and Depth Enhancement Display Techniques for 
Determination of Shape and Relative Position," 1990 International Symposium of 
the Society for Information Display, Las Vegas, NV (May 1990).

"Stereoscopic Computer Graphics," (Joint talk with L.F. Hodges and Y.D. Jean.), 
Hewlett-Packard Computer Graphics Symposium, Fort Collins, CO (June 1991).	

"Visible Surface Ray-Tracing of Stereoscopic Images," 30th Annual Meeting of the
SE ACM, Raleigh, NC (April 1992).


REFERENCES 

Available upon request
-- 
ARPA: steve1@cc.gatech.edu                       Nobody here had anything to do
                                                 with this, not even me.
"Careful! We don't want to learn 
	anything from this!" - Calvin, 5/17/92
Newsgroups: misc.jobs.resumes