1. A method of generating an image, the method performed by an image management apparatus having a controller, a communication unit, an image generation unit, and a database unit, the method comprising: mapping, by the image generation unit, a source image to a sphere; generating, by the image generation unit, a plurality of virtual planes according to a structure of a theater, the theater comprising a plurality of projection surfaces; projecting, by the image generation unit, the mapped source image on the plurality of the virtual planes; generating, by the image generation unit, a plurality of projection images to be projected on the plurality of the projection surfaces based on the projected mapped image on the plurality of the virtual planes; and sending, by the controller, the plurality of projection images to the theater through the communication unit, wherein the plurality of the virtual planes is generated based on a structural data of the theater stored in the database unit, wherein the source image comprises a plurality of pixels represented on a planar coordinate system using a horizontal angle value and a vertical angle value as parameters, and wherein each pixel of the plurality of pixels is mapped to a location corresponding to its horizontal angle value and vertical angle value around a center of the sphere.