When medication cannot help a patient with epilepsy, the only treatment is surgery. It is then critical to locate the seizure foci, and only operate in case of good localization. Radiologists and surgeons analyze images showing anatomy (MRI, CT) and functions (EEG, PET, fMRI) to take the right decision. Our goal is to develop new algorithms to integrate these data, and to give an accurate localization of the epilepsy focus.