An image processing apparatus includes at least one processor operatively coupled to a memory, serving as an obtaining unit configured to obtain a contrast material-enhanced image of an object, a first region extraction unit configured to extract a first region representing a first anatomical portion of the object from the image, an estimation unit configured to estimate a state of the image concerning a temporal change in gray level from the first region, and a second region extraction unit configured to extract a second region representing a second anatomical portion of the object from the image based on an estimation result obtained by the estimation unit.