Wavelet Coders

A wavelet transform can be viewed as a subband decomposition as described in section 2.1. The difference, though, is that the subband tree often is unbalanced in a wavelet decomposition, which means that the frequency splitting is nonuniform. This way, a filterbank which resembles the critical bands (see section 3.1.3) can easily be formed.

An example of a wavelet coder can be found in [10]. The authors claim perceptually nearly lossless coding at about 80 kbit/s at a coding complexity which requires only about 50% of the processing power of a Pentium-75 for either decoding or encoding.