APPARATUS FOR DETECTING AND RECOVERING DATA

摘要

PROBLEM TO BE SOLVED: To provide an apparatus for detecting and recovering data by increasing the space for a transform domain for embedding the data. SOLUTION: The data are embedded in material by using at least one transform domain representation to modulate a predetermined data sequence to form modulated data and combining the modulated data with the material. This data detecting and recovering apparatus comprises a transform processor operable to transform the material into the transform domain representation of information material, and a correlation processor operable to correlate transform domain data symbols for extracting the modulated data from modulation domain display with a reproduced version of the predetermined data sequence to form a correlation output signal and to recover the embedded data from the correlation output signal. The correlation processor is operable to repeat the correlation for transform domain data symbols and data symbols of the predetermined data sequence for each of a plurality of start positions in the transform domain.