Spectral enhancing method and device
AssigneesFrance Telecom, Telediffusion de France
InventorsPierrick PHILIPPE, Patrice COLLEN
Life of this patent
Estimating the term…
Abstract
The invention concerns a method for spectral enhancement and a device therefor. The inventive method is a method for enhancing spectral content of a signal having an incomplete spectrum including a first spectral band, the method including the following steps: at least transposing the spectral content of the first band into a second spectral band not included in the spectrum to generate a transposed spectrum signal, with spectrum limited to the second spectral band; transforming the spectrum of the transposed spectrum signal to obtain an enhancing signal; combining the incomplete spectrum signal and the enhancing signal to produce a spectrum enhanced signal. The invention is characterised in that the spectral content is subjected to a whitening step.
Claims20
A method of enhancing spectral content of a decoded signal, the signal having an incomplete spectrum including a first spectral frequency band, said method comprising the following steps:
- performing at least one translation of the spectral content of said first frequency band into a second frequency band excluded from said spectrum to generate a translated-spectrum signal, filtering the incomplete spectrum signal through a bank of analysis filters and applying outputs signal from said bank of analysis filters to translated orders of inputs of a bank of synthesis filters to generate a translated-spectrum signal having a spectrum restricted to said second spectral frequency band,
- shaping the spectrum of the translated-spectrum signal to produce an enhancement signal and,
- adding the enhancement signal to the incomplete spectrum signal to produce an enhanced-spectrum signal,
- the generation of the translated spectrum signal including whitening said spectral content so the spectrum of the translated spectrum signal is a whitened version of said spectral content.
A method of improving decoding of an incomplete spectrum signal, said incomplete spectrum signal having been produced by encoding in a spectrum limiting manner a wide frequency band source signal, comprising enhancing the decoded signal having an incomplete spectrum which include a first spectral frequency band having an envelope by:
- performing at least one translation of the spectral content of said first frequency band into a second frequency band excluded from said spectrum to generate a translated-spectrum signal, filtering the incomplete spectrum signal through a bank of analysis filters and applying outputs signal from said bank of analysis filters to translated orders of inputs of a bank of synthesis filters to generate a translated-spectrum signal having a spectrum restricted to said second spectral frequency band,
- shaping the spectrum of the translated-spectrum signal to produce an enhancement signal and,
- adding the enhancement signal to the Incomplete spectrum signal to produce an enhanced-spectrum signal,
- the generation of the translated spectrum signal including whitening said spectral content so the spectrum of the translated spectrum signal is a whitened version of said spectral content.
A device for enhancing spectral content of a decoded signal, the signal having an incomplete spectrum including a first spectral frequency band having an envelope, said device comprising:
- a generator adapted to apply at least one translation of the spectral content of said first frequency band into a second frequency band excluded from said spectrum, by filtering the incomplete spectrum signal through a bank of analysis filters and applying outputs signal from said bank of analysis filters to translated orders of inputs of a bank of synthesis filters to generate a translated-spectrum signal having a spectrum restricted to said second spectral frequency band, said generator being adapted to whiten said spectral content to generate a translated-spectrum signal,
- shaping means for shaping the spectrum of the translated-spectrum signal to produce an enhancement signal and
- an adder adapted to add the enhancement signal to the incomplete spectrum signal to produce an enhanced-spectrum signal.
Dependencies are inferred from the claim text.