抄録
We propose a similarity judgment method between critical point graphs (CPGs) in two volume data sets by using the directional element feature (DEF) that has been employed in the field of character recognition techniques (CRT). It becomes possible to perform classifying and searching volume data sets by using CPG with DEF. Critical Point (CP) shows the feature point of data, and CPG is a connection of those points by streamlines based on vector data of the field. Therefore, it is thought that CPG is an expression of the feature of volume data in a simple figure. CPG is consisted of curves and they are composed of small straight-line segments. Therefore, we applied extended DEF to the similarity judgment of CPG method.