The present invention has an objective of providing an optical disk having
a high resolution picture and a system for reproducing data on the
optical disk, which are compatible with a conventional system for
reproducing an ordinary resolution picture. A high resolution signal is
divided into a main signal and a sub signal by picture division means and
MPEG-encoded. The main signal and the sub signal are divided into frames
each having 1 GOP or more. The resultant first interleave block 54 and
second interleave block 55 are recorded alternately on an optical disk. A
high resolution reproduction apparatus reproduced both the first and
second interleave blocks, so that a high resolution picture is obtained.
A non-high resolution reproduction apparatus reproduces only the first or
second interleave block, so that an ordinary resolution picture.