A method for controlling an immersive head mounted display configured to provide a virtual space to a user. The method includes generating a virtual space image that forms a virtual space viewable by the user. The method further includes determining a reference line of sight. The method further includes determining a field-of-view region of the virtual space based on the reference line of sight. The method further includes generating a region of the virtual space image corresponding to the field-of-view region as a field-of-view image having an image quality higher than an image quality of a different portion of the virtual space image.