Patent ID: 8391212

Claim:
A method of post-processing of a frequency domain audio signal implemented by an audio post-processor, the method comprising: applying adaptive modification gain factor to each frequency coefficient of the frequency domain audio signal by using the audio post-processor; and determining gain factors based on Local Masking Magnitude and Local Masked Magnitude; wherein the Local Masking Magnitude and Local Masked Magnitude are estimated according to perceptual masking effects, wherein the Local Masking Magnitude is estimated by taking a weighted sum around a specific frequency at i: M 0 ⁡ ( i ) = ∑ k ⁢ w 0 i ⁡ ( k ) ·  F 0 ⁡ ( i + k )  , where M 0 (i) is the Local Masking Magnitude, w 0 i (k) is a first frequency dependent weighting window, F0(i) are frequency coefficients of the frequency domain audio signal before the post-processing is applied, and k is an index value, wherein Local Masked Magnitude M 1 (i) is estimated by taking a weighted sum the specific frequency at i: M 1 ⁡ ( i ) = ∑ k ⁢ w 1 i ⁡ ( k ) ·  F 0 ⁡ ( i + k )  , where M 1 (i) is the Local Masked Magnitude, w 1 i (k) is a second frequency dependent weighting window, and wherein weighting window w 1 i (k) is flatter and longer in the frequency domain than w 0 i (k), and wherein an initial gain factor for each frequency is Gain 0 ⁡ ( i ) = M 0 ⁡ ( i ) α · M 1 ⁡ ( i ) + ( 1 - α ) · M av , where i is a frequency index, M av is an Average Magnitude, and 0≦α≦1.