The MATLAB implementation of the Chroma Toolbox (by Ewert and Müller) is documented as providing the following audio features:
|Pitch||Semitone pitch spectrogram||88-bin elliptic filter bank, short-time energy summation|
|CP||Chroma||Pitch -> octave overlap -> various norm options|
|CLP||Chroma (log)||Pitch -> log compression -> octave overlap -> various norm options|
|CENS||Chroma energy-normalised statistics||Pitch -> octave overlap -> L1 norm -> quantize -> smooth and downsample -> L2 norm|
|CRP||(somewhat) Timbre-invariant chroma||Pitch -> log compression -> octave overlap -> cepstral reduction -> various norm options|
The MATLAB code makes various things configurable or optional that are not mentioned in the brief documentation, such as making log compression optional in the CRP features, and supporting a smooth-and-downsample option for chroma and CRP.