1. A pattern classifier device for determining whether an input pattern belongs to a class that is divided into a plurality of subclasses, the device comprising: a reception unit configured to receive the input pattern and attribute information of the input pattern; a decision unit configured to decide the subclass to which the input pattern is to belong, based on at least the attribute information; an execution unit configured to determine whether the input pattern belongs to the class, using a weak classifier allocated to the decided subclass, and output a result of the determination and a reliability of the weak classifier; a calculator configured to calculate an integrated value obtained by integrating an evaluation value based on the result of the determination and the reliability; and a determination unit configured to determine whether a termination condition of determination processing performed by the decision unit, the execution unit, and the calculator, has been satisfied, repeat the determination processing when the termination condition has not been satisfied, and terminate the determination processing and output the integrated value at the time of the termination when the termination condition has been satisfied.