Patent ID: 8649569

Claim:
An authentication apparatus for performing biometrics authentication comprising: an operation section which calculates, at the time of acquiring a living body image which an image capture apparatus generates by capturing an image of a living body, a difference, on the basis of the living body image and a registered image stored in a registered image storage section, between a relative position of the living body with respect to the image capture apparatus at the time of the image capture apparatus capturing the image of the living body for generating the living body image and a relative position of the living body with respect to the image capture apparatus at the time of the image capture apparatus capturing an image of the living body for generating the registered image; and an output section which outputs guidance information for prompting a reduction in the difference in the relative position calculated by the operation section, wherein: the output section outputs the guidance information in the case of similarity parameter between the living body image and the registered image being a value in a determined range, and the determined range of the similarity parameter is an area in which first similarity parameter distribution obtained in the case of the living body image matching the registered image and second similarity parameter distribution obtained in the case of the living body image not matching the registered image overlap.