Threshold calculation system, threshold calculation method, and computer program

A threshold calculation system, comprising:

• at least one memory that is configured to store instructions;
• and
• at least one first processor that is configured to execute the instructions to obtain a matching information that is used for matching of a biological body;
• obtain an attribute information indicating an attribute of the biological body or an attribute of the matching information;
• store the matching information and the attribute information for each biological body;
• extract, as sample data, a plurality of matching information, based on a predetermined condition about the attribute information;
• estimate a population from the sample data;
• calculate a threshold related to the matching information, based on a distribution of the estimated population;
• perform an authentication process based on a comparison between the matching information and the threshold;
• and
• control a gate based on a result of the authentication process,
• wherein the attribute information includes an environment attribute information indicating an environment in which the matching information is obtained,
• wherein the environment attribute information indicates pixel brightness, and
• wherein the at least one first processor is further configured to execute the instructions to extract the plurality of matching information as the sample data based on the pixel brightness.