A data structure of a stereo image file recorded on a recording medium which is readable by a computer to be applied to an image processing apparatus includes first monocular image data; second monocular image data having parallax with respect to the first monocular image data; and stereo data containing information regarding the data structure of the stereo image file, the stereo data including (i) information indicating whether or not the image file is a stereo image file, and (ii) information regarding arrangement of monocular image data items included in the image file.