1. A method for information processing that includes a learning process of generating a tree structured dictionary based on a plurality of patterns including a target object to be recognized, the method comprising: selecting a plurality of points from an input pattern based on a distribution of a probability that the target object to be recognized is present in the input pattern at each node of a tree structure generated in the learning process; and classifying the input pattern into a branch based on a value of a predetermined function that corresponds to values of the input pattern at selected plurality of points.