Patent ID: 6407738
Filing Date: 2002-06-18
Classification: G06T

Abstract:
A method for computing an analytical model, comprising the steps of:reading voxel data for an analytical object defined by a group of rectangular parallelepiped voxels (voxel reading step); determining whether each voxel is located in an inside, an outside, or an in-between boundary of said analytical object (boundary determining step); determining by a plurality of sub-steps including a feedback sub-step whether each voxel determined to be in the inside is connected to other voxels that are determined to be located at the boundary in the previous step (connection determining step); redefining a voxel that is determined to be in the inside in the boundary determining step as a new voxel which is larger than the boundary voxel (new voxel redefining step); wherein said sub-steps of said connection-determining step comprise the steps of: determining a hierarchical structure of voxels using a series of numerical designations from a boundary voxel that is determined to be located at the boundary in said boundary determining step (hierarchical structure determining step); and defining a voxel that is determined to be in an upper level of the hierarchical structure in the previous hierarchical structure determining step as a parent voxel and a voxel that is determined to be in an immediately lower level of the hierarchical structure in the previous hierarchical structure determining step as a child voxel (parent-child defining step), and wherein said new voxel redefining step comprises the steps of: redefining a parent voxel that corresponds to child voxels which are determined to be in the inside of the analytical object in said boundary determining step and which are next to the boundary voxel determined to be in the boundary of the analytical object in said boundary determining step as a second level voxel that has a twice as wide as the child voxel (first second-level hierarchical redefining step); redefining another parent voxel that corresponds to child voxels which are surrounded by said second level parent voxel or a child voxel that is determined to be in the inside of the analytical object in said boundary determining step as another second level voxel that has a twice as wide as the child voxel (second second-level hierarchical redefining step).