According to one embodiment, an image processing apparatus includes a storage unit configured to store data of a series of slice images associated with a region including a target region of an object, a first rest period specifying unit configured to specify a first rest period based on a change between images of the series of slice images, and a second rest period specifying unit configured to specify a second rest period shorter than the first rest period by tracking the target region on a plurality of slice images corresponding to the specified first rest period or a rest period enlarged from the first rest period.
