FIGURE 2.

Reflectance spectra with different preprocessing including of: the Savitzky–Golay smoothing; (a), the first derivative; (b), standard Normal variate; (c) and multiplicative scatter correction; (d), raw samples (e)

Reflectance spectra with different preprocessing including of: the Savitzky–Golay smoothing; (a), the first derivative; (b), standard Normal variate; (c) and multiplicative scatter correction; (d), raw samples (e)