The invention provides an image processing apparatus including a storage unit that stores a three-dimensional image of an observation target in a subject a projected-image generating unit that receives an image-acquisition position and an image-acquisition direction of an acquired two-dimensional superficial image of the observation target in a surface layer of the subject and that generates a two-dimensional projected image by projecting a position corresponding to the image-acquisition position of the three-dimensional image stored in the storage unit in the image-acquisition direction and a multiplication processing unit that receives the superficial image and the projected image and generates a multiplied image by multiplying brightness values of corresponding pixels in the superficial image and the projected image.
