1. A method of processing a medical image comprising an organ, the method comprising: a) obtaining a medical image; b) automatically estimating one or more organ intensity characteristics in the image, from contents of a region of the image that appears to correspond, at least in part, to at least a portion of the organ; c) providing a plurality of sets of organ intensity characteristics, each set different example of possible intensity characteristics of the organ; d) choosing one of the plurality of sets, that has organ intensity characteristics that provide a better match than one or more other sets to the estimated organ intensity characteristics of the image; e) setting values of one or more image processing parameters based on the organ intensity characteristics of the chosen set; and f) automatically processing the image using said values of image processing parameters, the processing comprising segmenting the organ in the image by using information, obtained by evaluating a local characteristic of one or more voxels in the image, on whether the voxels are likely to belong to the organ, based on the organ intensity characteristics of the chosen set.