1. A class configuration generation apparatus for selecting r number of features from n number of the features, both of n and r being integers, r<n, to obtain a class configuration, said class configuration being used for generating, through class categorization, informational data of a target position in a second informational signal comprised of multiple items of informational data when converting a first informational signal comprised of multiple items of informational data into the second informational signal, said apparatus comprising: a class configuration generation unit configured to generate (n−i) number of class configurations each including i number of the already selected features, said i being an integer, plus a feature selected from the remaining (n−i) number of the features; and a class configuration selection unit configured to select an optimal class configuration from the (n−i) number of the class configurations generated by the class configuration generation unit, using an arbitrary evaluation value, wherein the feature used in the class configuration selected by the class configuration selection unit is set as the already selected feature, and operations by the class configuration generation unit and the class configuration selection unit are repeated with values for said i sequentially varying from 0 to r−1, thereby obtaining a class configuration comprised of the r number of the features.