Patent ID: 7693319

Claim:
A computer-readable medium that stores executable instructions to carve volume data based on an image, the instructions for causing a machine to perform the steps of: a) generating a mask image to be carved from an input image; b) dividing a viewing transform matrix of the mask image into a shear transform matrix and a warp transform matrix, and calculating a scale factor from the shear transform matrix, wherein a transform matrix M scale is acquired from the shear transform matrix in consideration of characteristics of the shear transform matrix when a camera projection method is a near-to-far projection wherein the scale transform matrix is acquired by dividing the shear transform matrix S perspective into a pure shear transform matrix M shear and a scale transform matrix M scale in consideration of characteristics of the shear transform matrix based on matrix relationship shown in an equation which is expressed as: S Perspective = M Scale · M Shear = ( 1 0 - e o , w e o , x 0 0 1 - e o , y e o , z 0 0 0 1 0 0 0 - e o , w e o , z 1 ) where e o,x , e o,y , e o,z , and e o,w denotes x, y, z and w coordinates in an eye on coordinate system for an object, respectively; c) modifying the mask image to be parallel to an axis of the volume data based on the viewing transform matrix; d) shearing a volume slice in such a manner that the volume data can be parallel to viewing rays passing through a volume by using the mask image, and scaling the size of the volume slice by using the scale factor; and e) carving part of the volume slice through an operation between the mask image modified in the step c) and each volume slice sheared/scaled in the step d).