1. An automatic image preprocessing method for generating sub-volumes of a plurality of three dimensional medical volumes for semantic extraction of anatomical structures, the method comprising: providing, or acquiring and reconstructing, a medical three dimensional image as a volume, the volume including different anatomical structures or a part of an anatomical structure; partitioning the volume by generating volume cells of corresponding size; automatically detecting landmarks in the volume; matching the detected landmarks with at least one atlas image to generate an indexed volume, each of the volume cells indexed according to the matching; splitting the indexed volume into indexed sub-volumes according to atlas image data; and storing the indexed sub-volumes in a database.