An apparatus for generating a file comprises a file obtaining means, image composing means and a file generating means. The file obtaining means obtains a main image file in which a main stereographic image is recorded and a sub-image file in which a sub-image is recorded. The image composing means generates a first synthetic stereographic image by synthesizing a sub-stereographic image reconstructed to conform to a main stereographic image with the main stereographic image and generates a second synthetic stereographic image by synthesizing a main stereographic image reconstructed to conform to a sub-stereographic image with the sub-stereographic image. The file generating means generates a file of a predetermined format including the synthetic first and second stereographic images.