Specially formatted optical disk and method of playback

An optical disk recording digital image in information in the form of a succession of image information blocks, each comprising I-picture data of an I-picture obtained by intra-frame encoding, P-picture data of one or more P-pictures obtained by encoding with forward motion compensation, and B-picture data of B-pictures obtained by encoding with motion compensation using the data of the I- and/or P-pictures positioned in front and at the back thereof as references pictures,

• wherein presence/absence of scene change detected from the temporal change in the luminance or chrominance information of the image is recorded in an attribute data recording area at the head of each of the image information blocks.

A method of playing back an optical disc wherein the rotational speed of the optical disk during fast playback or reverse playback or motion picture image is higher than the rotational speed of the optical disk during normal playback.

A method of playing back an optical disk wherein the rotational speed of the optical disk is raised for a region in which no data needs to be read during fast forward or reverse playback of a motion picture image recorded on the optical disk, and is lowered to the linear velocity at which reproduction of data is possible, for a region in which I- and P-picture data is recorded.

An optical disk in which encoded I-picture data is divided into a plurality of sub-blocks wherein each I-picture sub-block is allocated encoded I-picture data according to the horizontal and vertical frequencies, from a DC component to the high-frequency components, track-adjacent I-picture sub-blocks in the track-adjacent image information blocks in the adjacent tracks are disposed with their order being altered, and a header or parity signal indicating which of the frequency components the content of each sub-block is for is recorded in front of each sub-block.

An optical disk storing digital image information in the form of a succession of blocks, each comprising a plurality of frames comprising, in mixture, I-picture data forming image information obtained by intra-frames encoding, P-picture data obtained by encoding with forward motion compensation, and B-picture data obtained by encoding with motion compensation using said I- and/or P-picture data positioned in front and at the back thereof as references,

• wherein the digital motion picture image information is divided into lower-layer data and upper-layer data wherein an image obtained by the lower-layer data alone has a resolution lower than a resolution of image data obtained from the combination of the upper-layer data and the lower-layer data, and
• wherein a header or parity signal for indicating the type of the data block is recorded in front of each data block,
• wherein the order of data arrangement of I-, P- and B-picture data within an image information block is different at least between track-adjacent image information blocks.