发明名称 |
Audio signal compression method, audio signal compression apparatus, speech signal compression method, speech signal compression apparatus, speech recognition method, and speech recognition apparatus |
摘要 |
An audio signal compression apparatus for compressively coding an input audio signal comprises a time-to-frequency transformation unit for transforming the input audio signal to a frequency domain signal; a spectrum envelope calculation unit for calculating a spectrum envelope having different resolutions for different frequencies, from the input audio signal, using a weighting function on frequency based on human auditory characteristics; a normalization unit for normalizing the frequency domain signal using the spectrum envelope to obtain a residual signal; a power normalization unit for normalizing the residual signal by the power; an auditory weighting calculation unit for calculating weighting coefficients on frequency, based on the spectrum of the input audio signal and human auditory characteristics; and a multi-stage quantization device having plural stages of vector quantizers connected in series, to which the normalized residual signal is input, and at least one of the vector quantizers quantizing the residual signal using the weighting coefficients. Therefore, a low frequency band, which is auditively important, can be analyzed with a higher frequency resolution as compared with a high frequency band, whereby efficient signal compression utilizing human auditory characteristics is realized.
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申请公布号 |
US6477490(B2) |
申请公布日期 |
2002.11.05 |
申请号 |
US20010892745 |
申请日期 |
2001.06.28 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
NAKATOH YOSHIHISA;NORIMATSU TAKESHI;TSUSHIMA MINEO;ISHIKAWA TOMOKAZU;SERIKAWA MITSUHIKO;KATAYAMA TARO;NAKAHASHI JUNICHI;YAGI YORIKO |
分类号 |
G10L19/00;H04B1/66;(IPC1-7):G10L19/06 |
主分类号 |
G10L19/00 |
代理机构 |
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代理人 |
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地址 |
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