Patent ID: 7574119

Claim:
An information playback apparatus configured to play back an information recording medium on which main image information having first resolution, first sub-picture information having the first resolution, second sub-picture information having second resolution which is lower than the first resolution, and attribute information including information denoting the resolution of the first and second sub-picture information have been recorded, the information playback apparatus comprising: a first image information output unit configured to overlap the first sub-picture information onto the main image information to be output in accordance with a required image output format; and a second image information output unit configured to overlap the second sub-picture information onto information into which the main image information has been converted to have the second resolution to be output in accordance with a required image output format, wherein the first and second sub-picture information comprise a plurality of sub-picture units each having a sub-picture unit header, the sub-picture unit header includes a previous header and a subsequent header, and information distinguishing between the first sub-picture information and the second sub-picture information is recorded on the previous header.