TC18 - Newsletter #5 - July 2005



1. Call for help: educational part of web site

2. Report on 12th DGCI conference in Poitiers



1. Call for help: educational part of web site (

We  would like to propose  to our community, via the  TC18 web page, a
good state of the art on discrete geometry.  To do  that, we need some
help from researchers involved in the different sub-fields of discrete
geometry.  The idea  is to  have a few  volunteers   for each of   the
sub-fields,   who will select and  define  basic references, lectures,
slides, and materials.

The defined sub-fields are:
	* Grids, cells, structures and topology (digital topology, 
graph theory and combinatorics)
      * nD objects and recognition (border tracking, discrete 
analytical objects (lines, planes, circles))
      * Discrete distances and skeletons (square and diamond 
distances, chamfer distances, euclidean distance, skeletons, medial 
axis and medial lines/surfaces)
      * Discrete geometrical transforms (rotations, magnification)
      * Various shape representation (hulls, multiscale shapes, 
Fourier moments, fractals)
      * Features extraction and similarity measures (convexity, 
lengths and areas, curvature, normals)
      * Examples of applications image rendering, compression, ...

If you can spend a few time to help,  please contact and
precise for which topic you are interested.

Concerning the  image  and  code databases,  several   people provided
various things... thanks to the contributors.

2. Report on 12th DGCI conference in Poitiers
(by Guillaume Damiand and Attila Kuba)

In 2005, the twelfth  edition of the  conference Discrete Geometry for
Computer Imagery was held in  Poitiers, France, April 13-15 2005.  The
conference   was organized  by the laboratory    SIC - "Signal, Image,
Communications" of  the University of Poitiers,  Centre National de la
Recherche  Scientifique  and   the  Technical  Committee  18  of   the
International Association of  Pattern Recognition. The series  of DGCI
conferences, started in 1991, is now the  main conference of TC18-IAPR
(TC18    opened     in  November     2002    on    discrete  geometry:

For this edition, Eric Andres was  the general chair, Pascal Lienhardt
the  program chair and Guillaume Damiand  the publications chair. DGCI
2005 was  sponsored by   the Faculty  of   Science, the University  of
Poitiers,   the  Region  of   Poitou-Charentes  and  the International
Association for Pattern Recognition  (IAPR). The conference venue  was
the  IFMI building on the  Futuroscope campus ground in Chasseneuil du
Poitou, near the Futuroscope park.

The  DGCI conference attracted  again for this  edition many excellent
papers  with  53 submitted  papers  from  21 countries.  After careful
reviewing  by two and sometimes three  reviewers,  36 papers have been
accepted from which 22  were selected for oral  presentation and 14 as
posters. The conference brought  together 84 participants, coming from
17 countries. As   usual at DGCI  conferences, there  was  a low  cost
registration for students.

This year's  conference   was organized  in combination  with  the 5th
Workshop  on Graph-based Representations in  Pattern Recognition.  The
GBR workshop aims at using  graph-based structures in image  analysis.
There is a  strong connection between the  community interested by the
GBR workshop and the discrete geometry community.  For this reason and
for the first time, GBR and DGCI were organized in the same place with
a  common session of  four papers, two  of which were submitted to GBR
and two to DGCI.

The talk and poster sessions covered topics such as reconstruction and
recognition, discrete   topology, uncertain  geometry,  visualization,
discrete models and transforms,   morphology and tomography  including
various applications.  Three   invited speakers showed new   important
views to the field of discrete imagery: Prof. Achille Braquelaire gave
a talk devoted  to "Representing and  Segmenting 2D Images by means of
Planar Maps  with  Discrete Embeddings:  from  Model to Applications";
Prof. Peter Veelaert gave  a talk on  "Uncertain Geometry in  Computer
Vision";  and Prof.   Jean-Pierre  Guedon  spoke  about  "The  Mojette
Transform: the First Ten Years".

The  conference was well  organized, the program  run smoothly without
any   problem.    The    available  infrastructure,   including    the
audio/projections,  computer   equipment,  Internet connection, worked
according to  high standard. The  social program contained a reception
and also a conference banquet, both of  them had big success among the

Proceedings of  the conference are published   by Springer in "Lecture
Notes in  Computer Science"  #3429.  Two special  issues will come out
soon: one in  "Image and Vision  Computing  Journal" and the  other in
"Computer and Graphics". The next DGCI Conference will held in Szeged,
Hungary, November  8-10    2006, organized  by   the   Dept. of  Image
Pocessinng and Computer Graphics, Univ. of Szeged,  with Prof.  Attila
Kuba at General Chair.

See  for more details about  the conference
and moreover about the TC18-IAPR on Discrete Geometry.

06th July 2005 - David and Annick.