From: rick@cs.arizona.edu (Rick Schlichting)
Newsgroups: comp.research.japan,comp.graphics
Subject: Kahaner Report: Computer Graphics Int '92, 22-26 June 1992, Tokyo
Date: 26 Aug 92 21:43:59 GMT
Followup-To: comp.research.japan


  [Dr. David Kahaner is a numerical analyst on sabbatical to the 
   Office of Naval Research-Asia (ONR Asia) in Tokyo from NIST.  The 
   following is the professional opinion of David Kahaner and in no 
   way has the blessing of the US Government or any agency of it.  All 
   information is dated and of limited life time.  This disclaimer should 
   be noted on ANY attribution.]

  [Copies of previous reports written by Kahaner can be obtained using
   anonymous FTP from host cs.arizona.edu, directory japan/kahaner.reports.]

To: Distribution
From: 
 David K. Kahaner
 US Office of Naval Research Asia
 (From outside US):  23-17, 7-chome, Roppongi, Minato-ku, Tokyo 106 Japan
 (From within  US):  Unit 45002, APO AP 96337-0007
  Tel: +81 3 3401-8924, Fax: +81 3 3403-9670
  Email: kahaner@cs.titech.ac.jp
Re: Computer Graphics International '92, 22-26 June 1992, Tokyo.
24 August 1992
This file is named "cgi-rpt.92"

ABSTRACT. Computer Graphics International '92, 22-26 June 1992, Tokyo,
summary report on important papers.

An earlier report [cgi.92, 29 July 1992] listed the program in detail,
as well as names and addresses of the organizers.  He we give a summary
of key papers and directions. The following report was prepared by

	Prof M.N.Mikhail
	Chairman, Department of Computer Science
	The American University in Cairo
	113 Sharia Kasr el Aini
	PO Box 2511, Cairo, Egypt
	 Tel: 3575312/5312; Fax: 355 7565
	 Email: MIKHAIL@AUC.EG

                      CG INTERNATIONAL '92 
                      -------------------- 
                         VISUAL COMPUTING 
                         ---------------- 

       Integrating Computer Graphics with Computer Vision 
       -------------------------------------------------- 

                        June 22-26, 1992 

                      Kogakuin University  

                          Tokyo, Japan 
                          ------------ 

The Technical sessions of the conference covered a broad Spectrum
of topics that included: 

- Volume visualization 
- Isosurfaces 
- Rendering 
- Virtual reality 
- Simulated nature 
- Dynamic and Kinematic Modelling 
- Sweep methods 
- Model Based coding 
- Interpolation and fitting 
- Rules and Constrain Based Modeling 
- Hidden surface and Hidden curve algorithms 
- Raster technology 
- Animation 
- Computer Aided Geometric Design 
- Tools and Programming Environments 

     Because of this large number of topics, very few papers are
presented in many of these topics.  In addition, there was an invited
talk on Holographic Video and two invited talks about the title theme of
the conference; "Integrating Computer Graphics with Computer Vision".
The first one of these talks was by professor A. Rosenfeld of the
university Maryland who presented his qualitative views that the link
between the Computer Graphics and Computer Vision is the advanced data
structure or the models they both use.

     The second talk was that of Professor Encarnacao who described the
experience and on going programs at the Technical University of
Darmshtadt in cooperation with other European countries in utilizing
Multimedia, visualization and Computer Graphics Techniques in Distant
Education and industrial training.

     The Conference keynote address was by Mr. I Wasaki (The senior Vice
president of NTT, Japan) who presented the Japanese interest and
determination of develop the Telecommunication in the 21st Century to
become more "Visual, intelligent and personal".  The paper outlined the
research and development activities carried by NTT to bring the VI&P
concepts to reality by the early years of the 21st Century.  The plans
are to complete the development of high speed optical fiber, broad band
(B-ISDN) early in the 2000's to all business users and by the 2015 to
all households Japan-Wide.

     This trend is very similar to that in the United States and Europe,
although, I am not aware of as clear a plan in the United States as this
talk lead me to believe exists in Japan.

     The volume visualization session consisted of four papers one from
the West(Norway) and three from the East.  The four papers are aiming at
speeding up the computation processes. The paper by Giertsen (IBM, Norway)
describes the use of a Scan plane buffer associated with each scan line.
This buffer maintains the individual contributions to the pixel values
of the scan line.  Further, the geometric primitives are scan converted
and the results inserted into a single scan line multiple layer
Z-Buffer.  Final pixel values for the scan line are determined by
merging the two buffers.

     The second paper by Shu and Chui (Singapore) suggests an
incremental approach to approximate the trilinear interpolation in a ray
casting technique for volume rendering that is twice as fast as the
usual trilinear interpolation process to determine the densities of the
sample points along a ray for the same image quality.  Another
efficiency improvement in the cost of volume reading is presented by
Koyamoda (IBM,Tokyo).  The idea here is to divide the volume into a set
of tetrahedral cells.  The amount of calculation is reduced by using the
exterior faces of cells rather than the ray as the base for processing.
The use of Ray Casting Technique in rendering of density clouds and
surfaces is described by Handana and Takada (both of NEC, Japan).

     The paper by Tanaka (ATR,Japan) on the visualization of Complex
shapes from sparse and incomplete range data is quite impressive work.
Their technique is based on differential geometry using adaptive and
arbitrary oriented meshes.

     Rendering of outdoor scenes by Professor Nakamae reports a very
impressive effort at Hiroshima University, they have been constant at
work in this problem for a number of years.  Their results are maturing
very nicely.

     A group from different Japanese Universities presented a method to
render curved surfaces under illumination of parallel cylindrical light
sources and to compute the shadows they cast under these conditions.
The work is successful in producing quite realistic images.

     The highlight of the virtual reality session was the paper by
Takemura and Kishino (ATR,Japan).  Their paper describe a case study of
building a prototype of cooperative work environment.  An implementation
of an environment where two operators can grasp and move by hand an
image is presented.  The System utilizes a hand gesture input system.

     Three eye-catching presentations were made in the simulated nature
session.  Modeling of compound leaves from the University of Calgary,
simulating bird's eye views from Carnegie Mellon, and synthetic fire
works from Japan.

     Turning to the subject of Computer Animation, this could be
accomplished on the basis of kinematics only.  This approach often
produce unrealistic results and always requires heavy involvement of the
animator, more realistic results can be produced by considering the
physical laws, the dynamics, of the motion.  The obstacle in this
approach is the complexity of the models and the computational cost
associated with it.  In this conference number of papers addressed
different overcoming this obstacle.

     Chua (University of Singapore) presented an adaptive time-step
solution scheme for the equation of motion for both rigid and elastic
bodies that included a treatment for collision avoidance.  The paper, as
expected, is mathematical in nature, but the presented animation case of
free falling elastic sheet is very interesting.

     The paper by Amakawa (University of California) addressed the
animation of multi-joint arm through training a neural network.

     On the same subject of computer animation, there were two invited
papers one by each of the couple, Nadia and Daniel Thalmann of the
University of Geneva.  Daniel presented the animation of growing objects
using L-system.  He simulated the interaction with the environment (e.g.
existence of wind) through the use of a vector force field.

     Nadia's talk concentrated on the simplification of (parts) of the
objects through the modification of polygonal meshes.  Her objective is
to reduce the complexity of the animation of the human body motion and
the collision of clothes with it during motion.

     From the world of animation, the conference turned to the subject
of generating a 3-D objects by sweeping 2-D ones.  A very involved paper
by three Korean authors discussed an algorithm to compute an
approximation to the general sweep boundary of a 2-D moving object that
changes its shape while traversing the trajectory.  The method depends
mainly on polygonal approximation of the trajectory and the object shape
at various points along the trajectory.  Each two consecutive instants
are linearly connected, then polygons are constructed to approximate the
sweep boundary.

     Another paper by professor Kunii of Japan with two young researches
from Singapore was presented [Kunii was the Japanese organizer of this
conference.].  The paper describes the integration of a the sweep
technique with the Homotopy model through the use of a one parameter
that controls the sweeping as well as the deformation of the cross
section shape.  The results are quite good.

     The sessions on "Model Based Coding" contained five papers, all
from Japan.  Four of the five papers, are related to description,
Synthesis and Control of facial expressions.  In one paper a description
is given of a method for the creation of a model and synthesis of facial
expressions using isodensity maps, the technique seems quite successful.
Another paper describes the use of input text to control the motion,
expression and mouth shape.  The synthetic actors are capable of talking
with synchronized correct mouth shape with the sound.  The demonstrated
results are interesting and impressive.  Another paper described a
hardware system and software algorithm for visual interactive control of
synthesized facial images using finger signs.  This is a substantial
amount of work by two young researchers from the University of Tokyo.

     Face-to-Face communication between the operator and the synthetic
actor is the subject of a paper by two researchers from Tokyo University
and Seiki University.  The paper presents a prototype of multimedia
man-machine interface based on the media conversion scheme.

    In the hidden surface and hidden curve session, a good paper by
three Japanese professors in three different Japanese Universities was
presented. Their algorithm utilizes Bezier clipping, rather than the
common polygonal approximation, for the computation of hidden surfaces,
interaction of curves, calculation of penetration points and the
extraction of contour lines.

     In the above, I didn't try describe all papers that were presented.
Rather the aim was to highlight the conference's important papers and
those that reflect todays interests and also to report on major
activities.

        M. N. Mikhail 

----------------------------END OF REPORT--------------------------------