Eidolon Project

Eidolon project

Eidolon ProjectEidolon is an Open-Source package written in Objective-C to provide a framework for testing reconstruction, attenuation and scatter correction methods for Positron Emission Tomography.


Eidolon was written by Dr Habib Zaidi in collaboration with Alix Hermann Scheurer (first release).

It was revised in 2001 by Frédéric Schoenahl with the grateful help of Karoly Makony (University of Budapest, Hungary) and Claude Comtat (SHFJ, France) for some compatibility and data format problems.


GNUstep is the implementation of the OpenStep environment on Unix operating systems.

The installation of the environment is not so easy because it consists in many individual packages and libraries to install. The full procedure is well described on Dennis Leeuw's page, in the administrator section, where the principles and installation of GNUstep is well documented.

The GUI of Eidolon was not tested with GNUstep, but the project is in active development and a compatibility should be tested soon.

Bug report

This is a bug-list. Temporarly, please email me for any BUG report.

08-06-2001 (F.Schoenahl)

Simulations with counts << 1000 does not work... 
state : currently at work...


Debug Eidolon with gdb / Objective - C

i. Preamble

Eidolon is written in Objective C, a very elegant language which is implemented on NeXTStep OS. However, using it on other systems is not easy. 

The GNUstep project attempts to adapt the NeXT environment for gnu-linux and unix systems.

The GNUstep project is still ... a project with all problems it implies. However it is already possible to do programming and implementations with the GNUstep API : have a look at WindowMaker.

Eidolon developer notes

i. Preamble

These pages have been made for people, especially students who are not unix-experts and who would like to modify the Eidolon package. A large project is not so easy to manipulate and some hints are useful to make the job easier.

Make a compilation the first time without modifications to check if all is working well.

$ make all

To be sure no residual object file is to be found, clean the ./objc directory with

$ rm -rf ./objc/*


The documentation of Eidolon is now divided in two parts: the user guide contains the required background and useful informations concerning PET and the way the Simulator works.

The second part is useful for developpers and contains a more detailed description of the sources. A second document is dedicated to the use of the GNU debugger GDB with Obj-C.

For compatibility problems have a look at the credits section.

Download the package

To download the first 1999 release of the free/open source package, users have to accept the licence agreement and fill a registration form on the PARAPET web site. This was suspended after the end of the project.

For the more recent releases (some bugs fixed) and other options added, including simulation of transmission scanning, please contact Frédéric Schoenahl or Dr Habib Zaidi.