|(communications)||noise shaping - Spectral noise transformation in a
quantisation processes. Noise is "colourised" in the time domain an/or frequency domain by adding parts of the
previous sample. The SNR bandwidth and SNR time integral
stay the same, so some noise decreases, some increases, but
overall noise always increases.|
An example of noise shaping in the frequency domain is quantisation of samples on a Compact Disc to reduce noise below -98 dB. The are different algorithms with slightly different filters, e.g. Super Bitmapping, 4D Recording.
A time domain example is MPEG-4 AAC TNS, which is a method to enhance quality by temporal forming of the noise in a transform block.