Wiki¶
The MATLAB implementation of the Chroma Toolbox (by Ewert and Müller) is documented as providing the following audio features:
| Name | Description | Process |
| 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.