1. A method for segmenting bone in spectral image data, which includes at least a first set of image data corresponding to a first energy and second set of image data corresponding to a second different energy, the method comprising: obtaining the spectral image data; extracting a set of features for each voxel in spectral image data; determining, for each voxel, a probability that each voxel represents bone structure based on the set of features; and extracting bone structure from the spectral image data based on the probabilities.