An extraction unit extracts, from volume data, a three-dimensional object having a tree-structure including plural end-points, plural branch-points, at least one edge each connecting an end-point and a branch-point, and at least one edge each connecting two branch-points. A division position search unit searches for a division candidate position that maximizes, with respect to an output range of a three-dimensional object creation apparatus, the size of at least one of division objects obtainable by dividing the three-dimensional object at the division candidate position on one of the edges of the tree-structure. A division unit divides, at a position on the one of the edges on which the division candidate position is present, the three-dimensional object into division objects the size of at least one of which is within the output range. An output unit outputs the at least one of the division objects to the three-dimensional object creation apparatus.