1. An information processing device, comprising: a central processing unit (CPU); and a memory connected to the CPU; wherein the CPU reads a program from the memory and achieves functions of: outputting proper identifiers for identifying learning images; calculating feature vectors of at least a part of patches included in registered patches that are registered in a dictionary for compositing a restored image; and calculating a similarity calculation method that calculates similarities between patches for classifying the proper identifiers to be given to the registered patches based on the feature vectors.