4. The method of claim 1 , wherein: the first transformation process comprises a sparsification operation comprising selecting one or more first features from a plurality of first outputs produced by the first transformation process based on the first characteristic; and the sparsification operation further comprises reducing a number of data elements by a factor of at least four.
4. The method of claim 1 , wherein: the first transformation process comprises a sparsification operation comprising selecting one or more first features from a plurality of first outputs produced by the first transformation process based on the first characteristic; and the sparsification operation further comprises reducing a number of data elements by a factor of at least four. 5. The method of claim 4 , wherein the first characteristic comprises a statistical parameter further determined based on the plurality of first outputs of the first transformation process.