1. An information processing method performed by an information processing apparatus including a processor, the information processing method comprising: a first image inputting step of inputting a first image captured by an imaging apparatus configured to capture a physical space; a second image inputting step of inputting a second image captured by an image capture unit configured to capture the imaging apparatus from an outside-in view position; a first detecting step, performed by the processor of detecting a feature quantity relating to image coordinates of a first index in the physical space, based on the first image input in the first image inputting step; a second detecting step of detecting a feature quantity relating to image coordinates of a candidate region relevant to a second index on the imaging apparatus, based on the second image input in the second image inputting step; and an identifying step, performed by the processor of identifying the candidate region as the second index, based on the feature quantity relating to the image coordinates of the first index detected in the first detecting step and the feature quantity relating to the image coordinates of the candidate region relevant to the second index.