An image processing apparatus, comprising: a first acquisition unit configured to obtain a first radiation image of a subject captured from a first direction; and a second acquisition unit configured to obtain a second radiation image of the subject captured from a second direction that intersects the first direction, characterised in that the image processing apparatus further comprises: an image corrector configured to correct one of the first radiation image and the second radiation image based on positional information of a device for capturing the one of the first radiation image and the second radiation image, or correct another one of the first radiation image and the second radiation image based on information on a position of a specific region of the subject obtained from the one of the first radiation image and the second radiation image; and a position determiner configured to determine a position of a magnetism generating part of the subject in the one of the first radiation image and the second radiation image, wherein the image corrector is configured to correct the another one of the first radiation image and the second radiation image to a size corresponding to the position of the magnetism generating part determined by the position determiner based on the position of the magnetism generating part, the position of the magnetism generating part being the information on the position of the specific region of the subject. a first acquisition unit configured to obtain a first radiation image of a subject captured from a first direction; and a second acquisition unit configured to obtain a second radiation image of the subject captured from a second direction that intersects the first direction, characterised in that the image processing apparatus further comprises: an image corrector configured to correct one of the first radiation image and the second radiation image based on positional information of a device for capturing the one of the first radiation image and the second radiation image, or correct another one of the first radiation image and the second radiation image based on information on a position of a specific region of the subject obtained from the one of the first radiation image and the second radiation image; and a position determiner configured to determine a position of a magnetism generating part of the subject in the one of the first radiation image and the second radiation image, wherein the image corrector is configured to correct the another one of the first radiation image and the second radiation image to a size corresponding to the position of the magnetism generating part determined by the position determiner based on the position of the magnetism generating part, the position of the magnetism generating part being the information on the position of the specific region of the subject. an image corrector configured to correct one of the first radiation image and the second radiation image based on positional information of a device for capturing the one of the first radiation image and the second radiation image, or correct another one of the first radiation image and the second radiation image based on information on a position of a specific region of the subject obtained from the one of the first radiation image and the second radiation image; and correct one of the first radiation image and the second radiation image based on positional information of a device for capturing the one of the first radiation image and the second radiation image, or correct another one of the first radiation image and the second radiation image based on information on a position of a specific region of the subject obtained from the one of the first radiation image and the second radiation image; and a position determiner configured to determine a position of a magnetism generating part of the subject in the one of the first radiation image and the second radiation image, wherein the image corrector is configured to correct the another one of the first radiation image and the second radiation image to a size corresponding to the position of the magnetism generating part determined by the position determiner based on the position of the magnetism generating part, the position of the magnetism generating part being the information on the position of the specific region of the subject.