The invention relates to a method for volumetric registration of a floating image with a reference image. At step 2' a floating image and a reference image are accessed. At step 4 and at step 6 a transformation function T and a similarity function (S) are accessed. The method according to the invention uses a-priori knowledge, notably a restricted parameter set, which is accessed at step 3. Preferably, the restricted parameter set is obtained by performing a suitable volumetric registration of a set of training images. The training set preferably comprises a sequence of floating images and reference images for each clinical application. Likewise, the training set may be composed of images of a patient group representing a certain group of disease, age, gender, race, etc. The invention further relates to a system and a computer program for enabling volumetric registration.