1. An information processing apparatus for registering a first image and a second image, wherein the first image is captured by a first imaging unit which captures an image of a state of an interior portion of an object under condition where a probe in the first imaging unit is situated at a non-contact position with respect to the object, and wherein the second image is captured by a second imaging unit which captures an image of a state of an interior portion of an object under condition where a probe in the second imaging unit is situated at a position in contact with a body surface of the object, comprising: a first acquisition unit configured to acquire the first image; a second acquisition unit configured to acquire the second image; a detecting unit configured to detect a position of the body surface of the object based on the first image; a third acquisition unit configured to acquire a position of surface of the probe in the second imaging unit when the second imaging unit captures the second image; a coordinate transformation unit configured to calculate a deformation amount of the object, which is caused when the probe in the second imaging unit is brought into contact with the body surface of the object, based on the position of the body surface of the object which is detected by the detecting unit based on the first image and the position of the surface of the probe in the second imaging unit which is acquired by the third acquisition unit, and estimate coordinate transformation parameter for transforming the coordinate between the first image and the second image based on the calculated deformation amount.