Abstract: Techniques are disclosed for predicting a property value of a sample of a particular sample type. A wavelet transformation is applied to the obtained spectrum to compute a sample set of wavelet coefficients in a plurality of wavelet bands. Calibration sets of wavelet coefficients are computed by wavelet transformations of respective NIR/MIR spectra obtained from calibration samples of at least the particular sample type. Each calibration set is associated with one or more reference property values of the respective calibration sample. The system creates a local PLS model of the to-be-determined property value of said sample by selecting a predefined number k of nearest neighbors of the sample set, and computes the local PLS model based on the selected k nearest neighbors and their associated reference property values. The property value of said sample is predicted by applying the local PLS model to the sample set.