Patent ID: 7580832
Filing Date: 2009-08-25
Classification: G10L

Abstract:
1. An apparatus for producing a fingerprint signal from an audio signal, comprising: a calculator for calculating energy values for frequency bands of segments of the audio signal which are successive in time, an energy value for a frequency band depending on an energy of the audio signal in the frequency band, so as to obtain a sequence of vectors of energy values from the audio signal, a vector component being an energy value in a frequency band; a scaler for scaling the energy values to obtain a sequence of scaled vectors; wherein the scaler includes a means for taking the logarithm and a suppressor for suppressing a steady component which is connected downstream of the means for taking the logarithm, wherein the suppressor for suppressing a steady component includes a high-pass filter; a low pass filter for temporally filtering the sequence of scaled vectors to obtain a filtered sequence which represents the fingerprint signal, or from which the fingerprint signal maybe derived; and a quantizer connected downstream of the filters and configured to quantize the filtered sequence or a signal based thereon so as to derive the fingerprint signal from the filtered sequence, wherein the quantizer is configured such that a width of a quantization level for a high energy value is larger than a width of a quantization level for a small energy value.