sent:    19 May 2003
subject: TC18 newsletter nr 2 - May 2003 

Dear all, 

This is our second electronic newsletter and it is sent to all people 
who have registered on the web page ( 
It will also be added on the web page. 

There are now 50 researchers who joined this group, and we hope that you 
will find some interesting and useful information on the web page. 

At the moment, certainly several of you are attending the IWCIA conference 
in Palermo (and we hope that you enjoy it). This conference is dedicated 
to combinatorial methods and problems in image analysis, which can have 
some connections with discrete geometry and topology. 

On the side of TC18, the two main points are: 
1. DGCI: the reviewing process is going on. 
2. Image/code data base : several are available now. 

These two points are developed below. Before that, thanks for being 
interested in TC18 on Discrete Geometry, and do not hesitate to give us 
your suggestions and ideas. 

Best regards. 

Annick and Stina. 



1. DGCI news 

2. Image/code data base 

3. Miscellaneous 


1. DGCI news 

Deadline for submission was on March 15th. 
68 papers have been submitted, and the reviewing process is going on. 
Acceptance notification will be sent on June 15th. 

Don't forget that the conference will take place in Napoli, from November 19 
to November 21 2003 ( 
During the conference, it is planned to have some meetings about TC18 and 
also about the role we can play in some international research programs. 

2. Image/code data base (by David Coeurjolly) 

The TC18 image and code data web page has opened two months ago. The idea 
is to make easy for everybody to try his own algorithms on the same images 
than other researchers, as well as to try other algorithms. 

First of all, we would like to thank all the contributors for their help 
during the setting up of databases. 
Right now, we have 71 binary images, 19 binary volume, 7 packages of codes. 
At the beginning, file formats have been chosen to encode data: 
- In dimension 2, we choose to use classical image file formats 
(PGM,PBM,TIFF,...). Many converters exist to handle these formats. 
- In dimension 3, we have created a specific file format called "VOL". 
Basically, the format contained a ASCII text header then a byte matrix to 
encode both binary and greyscale images. We have also developed a complete 
library (in C++) to handle such volumes. Some converters to a raw file 
format or to a Geomview file format (a visualisation tool) are provided. 

In the Code section, a volume generator with exact multi-grid signature 
(surface area, curvature, ...) have been published. It allows to create 
mathematical binary volumes (ellipsoid, torus,...) in a VOL file format. 

The other software are: 
- a discrete straight segment segmentation algorithm (in C) of a 
8-connected discrete curve (based on the Debled and Reveilles's 
- a simple tool to compute the digital plane pre-image of a set of voxels 
and thus a digital plane recognition (in C); 
- a skeletonization algorithm for 2D binary data by curvature program 
(in C, A. Imiya); 
- a boundary extraction algorithm for 3D binary image by distance 
transformation program (in C, A. Imiya). 

An important task is now to validate choices that have been made. Hence, we 
are very interested in feedback. So if you are using our data or if you 
want to comment the actual organisation of the web site, please contact us. 
Furthermore, if you want to fill some sections submitting your own data or 
software, just send an e-mail (David Coeurjolly ). 

3. Miscellaneous (but not the least) 

Joakim Lindblad, Centre for Image Analysis, Uppsala, Sweden, received his 
PhD degree in January 2003. He presented his works entitled 
"Development of Algorithms for Digital Image Cytometry". 

If you have good ideas to improve the presentation of the web page, 
or to help, do not hesitation to propose. 
The same holds if you have something you want to add, such as announcements 
for conferences, special issues or other important events. 

W B Master
Last modified: Mon May 19 13:33:21 MEST 2003