1. An image processing apparatus for converting captured image data into display image data for display on a display surface, comprising one or more processors and one or more memories storing one or more programs, wherein the one or more programs cause the one or more processors to perform:setting a display magnification on the display surface for the captured image data of an image of an object;
calculating, based on the display magnification and a first direction from an observer viewpoint toward a position on the display surface, a second direction from a capturing viewpoint of the captured image data toward the object; and
generating, based on the captured image data, the display image data such that the image of the object in the second direction from the capturing viewpoint of the captured image data is displayed at a position on the display surface in the first direction from the observer viewpoint,
wherein an elevation angle of the first direction is an elevation angle of the second direction multiplied by the display magnification, and an azimuth angle of the first direction is an azimuth angle of the second direction multiplied by the display magnification.