Feature extraction
The signal is preprocessed so that additional information is extracted.
- Local descriptors in face analysis:
responses of a set of 2-D Gabor filters tuned to different orientations and scales,
the output of multiscale morphological dilation-erosion
-In speech analysis, pre-emphasized voiced frames are windowed
Linear prediction analysis is applied to derive the linear prediction coefficients.
Linear prediction coefficients are converted to cepstral coefficients or to mel-frequency cepstral coefficients.