PROBLEM TO BE SOLVED: To generate a virtual endoscope image in which a center part of a lumen structure serves as the same way of being visible as a real endoscope image also in a bending section of a lumen structure.SOLUTION: An observation path setting unit 32 sets an observation path. A viewpoint setting and changing unit 33 sets a viewpoint on the observation path. When a virtual endoscopic image viewed from the viewpoint is generated, a visual range determination unit 34 identifies, based on a three-dimensional medical image, the position of a wall region of the tubular structure in a local observation direction at the viewpoint that has been set by the viewpoint setting and changing unit 33 and in the vicinity of the local observation direction. The visual range determination unit estimates, based on a positional relationship between the viewpoint and the wall region, a global observation direction at the viewpoint, and determines a visual range of the virtual endoscopic image in such a manner that image information about a region located in the global observation direction with respect to the viewpoint is represented at a central part of the virtual endoscopic image.COPYRIGHT: (C)2012,JPO&INPIT【課題】管腔構造の屈曲部においても、管腔構造の中心部が実内視鏡画像と同様の見え方となる仮想内視鏡画像を生成する。【解決手段】観察経路設定部32によって設定された観察経路上の、視点設定・変更部33によって設定された視点から見た仮想内視鏡画像の生成に際して、視野決定部34が、3次元医用画像に基づいて、視点設定・変更部33によって設定された視点における局所的な観察方向および局所的観察方向の近傍の方向に存在する管腔構造の壁部の位置を特定し、視点と壁部との位置関係に基づいて、視点における大域的な観察方向を推定し、視点に対して大域的観察方向にある画像情報が仮想内視鏡画像の中央部に表されるように、仮想内視鏡画像の視野を決定する。【選択図】図2
