A computer-implemented method for image registration includes accepting a three-dimensional (3-D) image of an organ. The image includes a first plurality of image points with respective image coordinates. A map defining a distribution of values of a physiological parameter over the organ is accepted. The map includes a second plurality of map points with respective map coordinates. Confidence levels are associated with one or more of the map coordinates and image coordinates. Weights are assigned to at least some of the map points and image points responsively to the confidence levels of the respective map coordinates and image coordinates. The 3-D image is fitted with the map by calculating a geometrical transformation between the map coordinates and the image coordinates based on the weights.
