1. An information processing apparatus comprising: a higher node having a plurality of weak discriminators that have learned a learning sample of a first label and a learning sample of a second label that has a predetermined coordinate relationship with the learning sample of the first label; a first lower node having a plurality of weak discriminators that have learned the learning sample of the first label based on the discrimination result of the higher node; and a second lower node that has no weak discriminator, wherein the first lower node performs an identification process on an input signal in order to recognize an image of the first label based on the discrimination result of the higher node, and the second lower node performs an identification process on the input signal in order to identify an image of the second label based on the discrimination result of the higher node by utilizing the weak discriminators in the first lower node according to the coordinate relationship.