THREE-DIMENSIONAL IMAGE GENERATION METHOD AND X-RAY CT SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce a stepwise artifact and a helical artifact by executing correction for reducing the adjacent direction component of a two-dimensional image and executing shading through the use of a corrected normal vector. SOLUTION: A shading part obtains the normal vector V of a polygon constituting a surface from an inputted visual point and a visual field center direction. Correction for reducing the adjacent direction component (Z direction component) of a CT image is executed on the vector V close to the boundary of the adjacent CT image and a correction normal vector V' is obtained. The normal vector V is used fro the CT image and the correction normal vector V' for the vicinity of the boundary of the CT image. Shading is executed by considering the visual point, a visual field center line direction and a light source and a three-dimensional image is generated. In the correction, an angle that an oblique line crosses the boundary of the adjacent two-dimensional images is brought close to an actual angle an stepwise artifact and helical artifact are reduced.