1. An image processing apparatus, comprising at least one processor and memory coupled to each other and cooperating to act as: a medical image obtaining unit configured to obtain a first medical image of an object in a first shape state; a deformation information obtaining unit configured to obtain deformation information indicating deformation of the object from the first shape state to a second shape state; a deformation image generating unit configured to generate a deformation image by deforming the first medical image based on the deformation information and to generate a conversion image for setting a region to be imaged by converting the deformation image; an imaging region setting unit configured to set the region to be imaged of the object in the second shape state based on a user operation on the conversion image, before taking a second medical image of the object in the second shape state; a display control unit configured to cause a display unit to display the conversion image and the region to be imaged; and an imaging region outputting unit configured to output information of the region to be imaged to a medical imaging apparatus in order to take the second medical image by using the medical imaging apparatus based on the information of the region to be imaged.