Image authentication apparatus, method, and storage medium using registered image

An image authentication method comprising:

• acquiring an image of an object to be authenticated from an image capturing apparatus;
• registering the image of an object in a registration dictionary as a registered image;
• setting a group to which the registered image is to be assigned;
• outputting a registration status of an object to be registered for each group based on the group of the registered image;
• determining, in a case where there is a group in which a number of the registered images is larger than a predetermined number, a parameter for calculating a degree of similarity between an input image and the registered image registered in the registration dictionary;
• and
• calculating the degree of similarity between the input image and the registered image registered in the registration dictionary using the determined parameter.

A non-transitory computer-readable storage medium that stores a computer program for causing a computer connected to an image capturing apparatus to operate as:

• an image acquisition unit configured to acquire an image of an object to be authenticated from the image capturing apparatus;
• a registration unit configured to register the image of an object in a registration dictionary as a registered image;
• a setting unit configured to set a group to which the registered image is to be assigned;
• an output unit configured to output a registration status of an object to be registered for each group based on the group of the registered image set by the setting unit;
• a determination unit configured to determine, in a case where there is a group in which a number of the registered images set by the setting unit is larger than a predetermined number, a parameter for calculating a degree of similarity between an input image and the registered image registered in the registration dictionary;
• and
• a calculation unit configured to calculate the degree of similarity between the input image and the registered image registered in the registration dictionary using the determined parameter.