Many X applications nowadays provide nice coloured icons which are stored into the binary file directly. If the application follows the NET_WM specifications, then it is possible to retrieve the icon from the _NET_WM_ICON window property, if it is defined. Extracting the _NET_WM_ICON of an X application is therefore simply a matter of calling XGetWindowProperty with the correct arguments.
To demonstrate how this can be done in practice, I wrote a small program called xgeticon which let the user choose the window of a running X application and save the extracted icon into the file provided as argument. The program is inspired from xprop and uses the procedure explained here (dead) to retrieve and save the icon. The icon can be saved into any of the file formats supported by Imlib2; the format being automatically determined from the file extension.
The official and final version of my PhD thesis dissertation is out. It is available here or from the EPFL library website. The title is Inference in Switching Linear Dynamical Systems Applied to noise robust speech recognition of isolated digits. The dissertation is mainly talking about how to perform approximate inference in Switching and Bayesian Switching Linear Dynamical Systems. The devised algorithms are applied to the automatic recognition of isolated spoken digits in noisy environments. Additional information can be found here.
I am gently moving to WordPress. My old website is still available at the address http://mesot.swisspowered.net/oldsite. For the moment, only the pages about installing ATLAS and CLAPACK on Linux, as well as the list of my publications, have been translated. The other pages will hopefully be available soon. In the meantime, if you cannot find something you are looking for, then try the old website.