Data hiding method and system for embedding and extracting information in signals

A method for extracting embedded information from an input signal comprising a plurality of elements, the method comprising:

• (a) specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of a corresponding code signal, the code signal having a plurality of elements, and having positive and negative values;
• (b) calculating a block value by correlating said code signal with said block with respect to each block and obtaining a statistical value from the block values;
• and
• (c) extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted.

A data hiding system for embedding information in an input signal comprising a plurality of elements, the system comprising:

• (a) a unit for preparing a code signal having a plurality of elements, said code signal having at least positive and negative values;
• (b) a unit for specifying blocks in said input signal into which blocks certain information is embedded, said blocks having a size corresponding to that of corresponding parts of said code signal;
• (c) a unit for determining an amount to modify elements of the input signal based on the values of the code signal corresponding to a block and an encoding method that specifies how the code signal is to be applied to the block based on meaning of information to be embedded;
• (d) a unit for adding the determined amount to the input signal at the block;
• and
• (e) a unit for operating the units (c) to (d) with respect to the blocks so that information is embedded in the blocks.

A system for extracting embedded information from an input signal comprising a plurality of elements, the system comprising:

• (a) a unit for specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of a corresponding code signal, the code signal having a plurality of elements, and having positive and negative values;
• (b) a unit for calculating a block value by correlating said code signal with said block with respect to each block and obtaining a statistical value from the block values;
• and
• (c) a unit for extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted.

A system for embedding information into data, the information controlling use of said data, said data comprising a plurality of elements, the system comprising:

• (a) a unit for preparing the control information to be embedded;
• (b) a unit for preparing a code signal having a plurality of elements, said code signal having positive and negative values;
• (c) a unit for specifying blocks of the data elements into which blocks said control information is embedded, said blocks having a size corresponding to that of corresponding parts of said code signal;
• (d) a unit for determining an amount to modify elements of the data based on the values of the code signal corresponding to a block and an encoding method that specifies how the code signal is to be applied to the block based on meaning of information to be embedded;
• (e) a unit for adding the determined amount to the data at the block;
• and
• (f) a unit for operating the units (c) to (d) with respect to this blocks so that information is embedded into the blocks.

A system for extracting embedded control information from an input signal, and controlling use of said input signal, said input signal comprising a plurality of elements, the system comprising:

• (a) a unit for specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of a corresponding code signal, the code signal having a plurality of elements, and having positive and negative values;
• (b) a unit for calculating a block value by correlating said code signal with said block with respect to each block and obtaining a statistical value from the block values;
• (c) a unit for extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted;
• and
• (d) a unit for controlling use of said input signal according to the extracted control information.

A method for extracting embedded information from an input signal comprising a plurality of elements, the method comprising:

• (a) specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of corresponding parts of a code signal, the code signal having a plurality of elements, and having positive and negative values;
• (b) calculating a block value by multiplying said code signal and a corresponding block of the input signal to compute a product and summing the product with respect to each of said blocks, and obtaining a statistical value from the sum of block values;
• and
• (c) extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted.

A system for extracting embedded information from an input signal comprising a plurality of elements, the system comprising:

• (a) a unit for specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of corresponding parts of a code signal, the code signal having a plurality of elements, and having positive and negative values;
• (b) a unit for calculating a block value by multiplying said code signal and a corresponding block of the input signal to compute a product and summing the product with respect to each of said blocks, and obtaining a statistical value from the sum of block values;
• and
• (c) a unit for extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted.

A system for extracting embedded control information from data, and controlling access to said data, said data comprising a plurality of elements, the system comprising;

• (a) a unit for specifying blocks in which information is embedded in said data, said blocks having a size corresponding to that of a corresponding code signal, the code signal having a plurality of elements, and having positive and negative values;
• (b) a unit for calculating a block value by multiplying said code signal and a corresponding block of the data to compute a product and summing the product with respect to each of said blocks, and obtaining a statistical value from the sum of block values;
• (c) a unit for extracting embedded control information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of control information which should be extracted;
• and
• (d) a unit for controlling access to said data according to the extracted control information.