Human auditory system modeling with masking energy adaptation

A non-transitory computer readable medium on which is stored instructions, which when executed by a processor, perform a method of:

• transforming a block of samples of an audio signal into a frequency spectrum comprising frequency components;
• from the frequency spectrum, deriving group masking energies, the group masking energies each corresponding to a band of frequency components in the frequency spectrum;
• for each of plural bands of frequency components, allocating the group masking energy to the frequency components in a corresponding band in proportion to energy of the frequency components within the corresponding band to provide adapted mask energies for the frequency components within the corresponding band, the adapted mask energies providing masking thresholds for a perceptual model of the audio signal;
• adapting a digital data signal according to the masking thresholds;
• identifying a location within the audio signal where insertion of the digital data signal exceeds a clipping limit;
• and
• applying a clipping function to smooth a change made to insert the digital data signal around the location.

A electronic device comprising:

• an audio sensor;
• a memory;
• a processor coupled to the memory, the processor configured to execute instructions stored in the memory to:
• convert a block of samples of an audio signal obtained from the audio sensor into a frequency spectrum comprising frequency components;
• compute group masking energies from the frequency spectrum, the group masking energies each corresponding to a group of neighboring frequency components in the frequency spectrum;
• allocate the group masking energy to the frequency components in a corresponding group in proportion to energy of the frequency components within the corresponding group to provide adapted mask energies for the frequency components within the corresponding group, the adapted mask energies providing masking thresholds for a psychoacoustic model of the audio signal;
• adapt a digital data signal according to the masking thresholds;
• identify a location within the audio signal where insertion of the digital data signal exceeds a clipping limit;
• and
• apply a clipping function to smooth a change made to insert the digital data signal around the location.

A method of saturation handling for audio watermarking of an audio signal, the method comprising:

• transforming a block of samples of the audio signal into a frequency spectrum comprising frequency components;
• from the frequency spectrum, deriving group masking energies, the group masking energies each corresponding to a group of neighboring frequency components in the frequency spectrum;
• and
• for each of plural groups of neighboring frequency components, allocating the group masking energy to the frequency components in a corresponding group in proportion to energy of the frequency components within the corresponding group to provide adapted mask energies for the frequency components within the corresponding group, the adapted mask energies providing masking thresholds for a perceptual model of the audio signal;
• applying the perceptual model to the audio signal to produce masking thresholds for inserting a digital data signal;
• adapting a digital data signal according to the masking thresholds;
• identifying a location within the audio signal where insertion of the digital data signal exceeds a clipping limit;
• and
• applying a clipping function to smooth a change made to insert the digital data signal around the location.