An image acquisition unit acquires a real endoscope image. A first evaluation value acquisition unit acquires a first evaluation value indicating the hole likeness of the insertion destination of an endoscope, and a second evaluation value acquisition unit acquires a second evaluation value indicating the boundary likeness of a plurality of bronchi at the bronchial branch. A determination unit determines whether or not a branching structure is included in the real endoscope image using both the first and second evaluation values. When it is determined that a branching structure is included, a virtual endoscope image generation unit generates a virtual endoscope image, and a display control unit displays the real endoscope image and the virtual endoscope image on a display.