@2-ton : Thanks for giving your opinion. I thought that maybe in the expression 'GREYC's Magic Image Computing', the 'Magic' could be seen as referring to the 'Image' word, instead of 'Computing', or even to 'GREYC'. And to me 'Magic Image' has no real meaning.
Not sure about this, as I'm not a native speaker, but 'GREYC's Magic for Image Computing' seems to clearly separate between the 'GREYC Magic' thing and the 'Image Computing' field.

GreyC's = who's
Magic Image Computing = what it is

In that case, you are correct that the 'for' does add a more clear explanation.
CreyC's = who's
Magic = what it is
for Image Computing = what it's used for

Thanks for these precision 2-ton, then it confirms my idea about choosing "GREYC's Magic for Image Computing", as a final choice. If someone else comes with a better suggestion, please let us know
Otherwise, I think I will probably post a 'Call for New Logo' message in the forum. I'm definitely not talented enough to create something simple and stylish enough to be put on the web page, and I cannot modify the current logo at all (I have it only in a low resolution).

Are you looking for something completely different or an upgrade based on the Gmicky logo?

I'm open to any good looking logo. Looking for something simple but stylish, that could be integrated well on the current web page, and that could be used in other visuals (slides, flyers, etc...).
Having Gmicky on it is not mandatory, but could be nice (or maybe not gmicky, but an element of it). I don't have any presupposition on how it must look like.