Coding apparatus and method, decoding apparatus and method, data processing system, storage medium, and signal

摘要

The invention relates to a coding apparatus for embedding second data into first data without deteriorating the first data and a decoding apparatus for decoding coded data into original first data and second data without deteriorating those data. The invention provides a coding apparatus which determines change subject data and change data based on a frequency distribution of at least partial data of the first data, and embeds second data into first data by causing a change from the change subject data to the change data according to the second data. The invention also provides a decoding apparatus which determines change subject data and change data based on a frequency distribution of at least partial data of coded data in which second data is embedded, and decodes the coded data into original first data and restores the second data that is embedded in the coded data by restoring the change subject data from the change data.