According to an embodiment, an image processing apparatus includes an acquiring unit configured to acquire volume data of a three-dimensional image and a superimposed image generating unit configured to generate a superimposed image that is made by superimposing light information on a depth image when a parallax image obtained by rendering the volume data from multiple viewpoints is displayed as a stereoscopic image. The light information represents a relationship between a position in a depth direction of the stereoscopic image and resolution of the stereoscopic image. The depth image is obtained by rendering the volume data from a depth viewpoint at which the entire volume data in the depth direction is viewable.
