SHAPE-BASED SPECTRAL CONTRAST DESCRIPTOR

Mel-frequency cepstral coefficients are used as an abstract representation of the spectral envelope of a given signal. Although they have been shown to be a powerful descriptor for speech and music signals, more accurate and easily interpretable options can be devised. In this study, we present and evaluate the shape-based spectral contrast descriptor, which is build up from the previously proposed octave-based spectral contrast descriptor. We compare the three aforementioned descriptors with regard to their discriminative power and MP3 compression robustness. Discriminative power is evaluated within a prototypical genre classification task. MP3 compression robustness is measured by determining the descriptor values' change between different encodings. We show that the proposed shape-based spectral contrast descriptor yields a significant increase in accuracy, robustness, and applicability over the octave-based spectral contrast descriptor. Our results also corroborate initial findings regarding the accuracy improvement of the octave-based spectral contrast descriptor over Mel-frequency cepstral coefficients for the genre classification task.