1. An information processing apparatus, comprising: circuitry configured to pick up an image of a real space to obtain a first background image, estimate, when the first background image includes a first marker image, a first positional relationship as a spatial positional relationship of the information processing apparatus to the marker based on the first marker image, and estimate, when the first background image does not include the first marker image, the first positional relationship based on a displacement of a feature point extracted from the first background image, the feature point being different from the first marker image, the first marker image being an image of a marker previously registered and located in the real space, generate a first additional image based on the first positional relationship, and synthesize the first additional image and the first background image into a synthetic image, and display the synthetic image.