Section: Other Grants and Activities

Association with MIT CSAIL graphics group

Participants : Adrien Bousseau, Joëlle Thollot, Nicolas Holzschuch, Cyril Soler, Kartic Subr.

INRIAs office of international relations has set up in 2001 a program for associated teams that bring together an INRIA project-team and a foreign research team, providing a form of institutional recognition to stable scientific collaborations involving several researchers on each side.

An associated team was created for the 2003-2005 period between ARTIS and the MIT graphics group (CSAIL Lab) on the subject of Flexible Rendering. It has been extended for 2006, 2007 and 2008, then extended one last time in 2009 (with no budget). This association, now in its seventh year, has been extremely positive: several research actions (described above in the results sections) have been performed jointly with MIT researchers.

The associated team has helped this collaboration on a practical level by providing funding for researcher exchanges. The two teams know each other very well and frequent visits and conference calls make actual cooperation a reality (for instance publications  [34] , [35] , [38] , [37] , [39] , [36] ,[18] , [15] are co-signed by researchers from the two groups).

The activity of the associate team in 2009 focused on the following three items:

• We continued our research project on the frequency analysis of light transport, with an emphasis on the development of practical algorithms for the evaluation of frequency spectra in photon tracing. This work has resulted in two papers accepted for publication in ACM Transactions on Graphics [18] , [15] .

• Adrien Bousseau conducted a long term stay at MIT (3 months), working with Fredo Durand on Computational Photography. They are working on the separation of a photograph in two composants: lighting and color. This work offers many potential applications for image editing softwares, and we are cooperating with the Adobe Research center in Boston, especially with Sylvain Paris, a former ARTIS Ph. D. student. This work has resulted in a common publication at Siggraph Asia 2009 [12] .

• We have started a new research direction on edge-preserving multiscale decomposition. Our algorithm takes as input a picture, and produces a multiscale representation of this picture, separating fine details, medium details and large-scale details. Our algorithm works by detecting oscillations in the pictures. The main advantage is that it is edge-preserving, that is even the large-scale version does not blur the edges. This work resulted in a common publication at Siggraph Asia 2009 [19] .