Device and method for data embedding and device and method for data extraction

A data extraction device that extracts data that is embedded into a prediction parameter, the device comprising:

• a storage unit configured to store a code book that includes a plurality of prediction parameters that are used for data embedding;
• a processor;
• and
• a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute,
• specifying candidates of a prediction parameter, the candidates being extracted in prediction coding, from the code book on the basis of a prediction parameter that is a result of the prediction coding, the prediction coding being based on signals of other two channels, of a signal of one channel among signals of a plurality of channels and the signals of the other two channels, and specifying the number of candidates of the prediction parameter;
• extracting a number that is embedded into the prediction parameter and does not exceed the number of candidates, from the candidates, the candidates being specified, of the prediction parameter, on the basis of a predetermined data embedding rule corresponding to a number base based on the number of candidates;
• performing reverse conversion of number base conversion into a number base based on the number of candidates, with respect to the number that is extracted and does not exceed the number of candidates;
• and
• extracting data that is embedded, on the basis of a conversion result of the converting.

A data embedding method, comprising:

• extracting a plurality of candidates, of which a prediction error in prediction coding, the prediction coding being based on signals of other two channels, of a signal of one channel among signals of a plurality of channels is within a predetermined range, of a prediction parameter from a code book that includes a plurality of prediction parameters and extracting the number of candidates of the prediction parameter, the candidates being extracted;
• converting, by a computer processor, at least part of data that is an embedding object into a number base based on the number of candidates;
• and
• selecting a prediction parameter, the prediction parameter being a result of the prediction coding, from the candidates, the candidates being extracted, in accordance with a predetermined embedding rule, the predetermined embedding rule corresponding to the number base that is converted in the converting, so as to embed the data, the data being an embedding object, into the prediction parameter as the number base.

A data extraction method, comprising:

• specifying candidates of a prediction parameter, the candidates being extracted in prediction coding, from the code book, the code book being included in a data extraction device and including a plurality of prediction parameters that are used for data embedding, on the basis of a prediction parameter that is a result of the prediction coding, the prediction coding being based on signals of other two channels, of a signal of one channel among signals of a plurality of channels and the signals of the other two channels, and specifying the number of candidates of the prediction parameter;
• extracting, by a computer processor, a number that is embedded into the prediction parameter and does not exceed the number of candidates, from the candidates, the candidates being specified, of the prediction parameter, on the basis of a predetermined data embedding rule corresponding to a number base based on the number of candidates;
• and
• extracting data that is embedded, by performing reverse conversion of number base conversion into a number base based on the number of candidates, with respect to the number that is extracted and does not exceed the number of candidates.

A computer-readable storage medium storing a data extraction program that causing a computer to execute a process, comprising:

• specifying candidates of a prediction parameter, the candidates being extracted in prediction coding, from the code book, the code book being included in a data extraction device and including a plurality of prediction parameters that are used for coding, on the basis of a prediction parameter that is a result of the prediction coding, the prediction coding being based on signals of other two channels, of a signal of one channel among signals of a plurality of channels and the signals of the other two channels, and specifying the number of candidates of the prediction parameter;
• extracting a number that is embedded into the prediction parameter and does not exceed the number of candidates, from the candidates, the candidates being specified, of the prediction parameter, on the basis of a predetermined data embedding rule corresponding to a number base based on the number of candidates;
• and
• extracting data that is embedded, by performing reverse conversion of number base conversion into a number base based on the number of candidates, with respect to the number that is extracted and does not exceed the number of candidates.