| 摘要 |
In an imaging system and method a volume image memory (24) stores an electronic image representation of a volumetric region, such as a volumetric region examined by a medical diagnostic scanner (10). A sub-region of interest of the volume is selected (30) and the surface of the selected region or object of interest is divided into triangular surface regions with a triangular surface processor (38). A vertex merging processor (40) examines the triangles to locate vertices spaced by less than a preselected minimum. Vertices closer than the preselected minimum are replaced with a vertex at a median position merging the triangle into adjacent triangles. A vertex removal processor (50) identifies groups of triangles having a common vertex (Vc) that form a pyramid. The surface normals (N) of the triangles which define a pyramid are examined to determine whether they are within a preselected deviation of parallel. The altitude of the pyramid, i.e., a distance between the common vertex and an average plane (Pavg) of the triangles is compared with a preselected maximum height to see if they are below it. Triangle groups which pass the surface normal and maximum height tests have their common vertex removed (72) and are retriangulated (74) to reduce the number of triangles by two. An image processor (84) converts the angles of viewing and illumination direction relative to the surface normal of each visible triangle into a corresponding image value, e.g. gray scale value, for display on a video monitor (34). <IMAGE> |
