1. An image processing device comprising: a storage unit configured to store a plurality of items of image data respectively used for a plurality of processes for rendering an image to be displayed; a rendered area identification unit configured to identify frame coordinates of an area that is located in the image to be displayed and that is to be newly displayed in response to a request input by a user to move a viewpoint; and a displayed image processing unit configured to render an area in a displayed image corresponding to the frame coordinates, by using the image data stored in the storage unit, and configured to output data for the rendered area to a display device, wherein, the displayed image processing unit determines which of one or more processes to perform among the plurality of processes that respectively use the plurality of items of image data, depending on the height of a viewpoint responsive to the request to move the viewpoint.