Optical disk having electronic watermark, reproducing apparatus thereof and copy protecting method using the same
AssigneeKabushiki Kaisha Toshiba
InventorsHisashi Yamada, Hideo Ando, Tadashi Kojima, Kouichi Hirayama
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Abstract
A copy protecting method for an optical medium includes a writing step of writing watermark data as ECC data in a data storage area of a disk having a certain data stored therein.
Claims22
A data reproduction method for reproducing data made up of a plurality of error correction code blocks, each of the error correction code blocks including block data, inner parity code (PI) data serving as error correction data, and outer parity code (PO) data, each of the error correction code blocks having a plurality of electronic watermark information data, said method comprising:
- extracting the electronic watermark information data, based on positional information data that represents where the electronic watermark information data is recorded in each of the error corrections code blocks;
- and
- checking through data included in one error correction code block by use of the inner parity code data, the outer parity code data and the block data, performing error correction processing on the data included said one error correction code block, and sequentially continuing checking through data with respect to each of the error correction code blocks by use of the inner parity code data, the outer parity code data and the block data, said electronic watermark information data being regarded as an error and subject to error correction,
- wherein said electronic watermark information data (a-p) of each of the error correction code blocks is randomly arranged in at least one of said block data, inner parity code (PI) data, and outer parity code (PO) data, and said electronic watermark information data (a-p) includes error correction code.
A data encoding method comprising:
- generating block data;
- adding inner parity code data, which serves as error correction data, and parity code data to said block data, thereby making an error correction code block;
- and
- inserting electronic watermark information data in said error correction code block;
- wherein said electronic watermark information data (a-p) of each of the error correction code blocks is randomly arranged in at least one of said block data, inner parity code (PI) data, and outer parity code (PO) data, said electronic watermark information data (a-p) includes error correction code, and the electronic watermark information data is regarded as an error and subjected to error correction.
A data reproduction method for reproducing data made up of a plurality of error correction code blocks, each of the error correction code blocks including block data, inner parity code (PI) data serving as error correction data, and outer parity code (PO) data, each of the error correction code blocks having a plurality of electronic watermark information data, said method comprising:
- extracting the electronic watermark information data, based on positional information data that represents where the electronic watermark information data is recorded in each of the error correction code blocks;
- and
- correcting an error in one error correction code block by use of the inner parity code data, the outer parity code data and the block data and sequentially correcting an error in data with respect to each of the error correction code blocks by use of the inner parity code data, the outer parity code data and the block data,
- wherein said electronic watermark information data (a-p) of each of the error correction code blocks is randomly arranged in at least one of said block data, inner parity code (PI) data, and outer parity code (PO) data, and said electronic watermark information data (a-p) includes error correction code.
Dependencies are inferred from the claim text.