Model building apparatus, model building method, computer program and recording medium

Abstract

A model building apparatus includes: a building unit that builds a generation model that outputs an adversarial example, which causes misclassification by a learned model, when a source sample is entered into the generation model; and a calculating unit that calculates a first evaluation value and a second evaluation value, wherein the first evaluation value is smaller as a difference is smaller between an actual visual feature of the adversarial example outputted from the generation model and a target visual feature of the adversarial example that are set to be different from a visual feature of the source sample, and the second evaluation value is smaller as there is a higher possibility that the learned model misclassifies the adversarial example outputted from the generation model. The building unit builds the generation model by updating the generation model such that an index value based on the first and second evaluation values is smaller.