Fig. 3From: Classification of audio signals using spectrogram surfaces and extrinsic distortion measuresVisualization of the process of measuring distortions associated with the parametrization problem. The figure depicts, from left to right: a sound spectrogram, a triangular mesh \((\mathcal {V},\Im )\) representation of the spectrogram surface, an initial mapping of \((\mathcal {V},\Im )\) onto the plane and the final flattening of the mesh, computed by means of the ABCD algorithmBack to article page