METHOD AND APPARATUS FOR DETERMINING PRESENCE OF REFERENCE PATTERN IN RECEIVED SIGNAL, POSSIBLY WATERMARKED Russian patent published in 2013 - IPC G10L19/18 

FIELD: physics.

SUBSTANCE: method of determining presence of a reference pattern in a received and possibly watermarked audio signal or video signal, wherein: for the current part of said received signal, correlations with each of the reference patterns are calculated; among amplitude values of the correlation result, groups of values are found, in which the magnitude of the current amplitude value of the correlation result, called the main peak, is greater than a first threshold value, and the magnitude of the main peak is also greater than the magnitude of its left side neighbouring amplitude value of the correlation result, and also greater than the magnitude of its right side neighbouring amplitude value of the correlation result; additional peaks are found in the given vicinity of each of the main peaks; for each of the groups of values, the magnitudes of the main peak and the additional peaks are combined, thereby forming an overall value for the group; for each of the reference patterns, the maximum value among the overall values of groups is determined, wherein if the greatest of these maximum values is greater than the given or variable threshold value, the corresponding reference pattern is considered to be present in the received signal.

EFFECT: high reliability of correlation systems for detecting watermarking in the presence of an echo or reverberation.

20 cl, 5 dwg