A Bootstrap-VIP approach for selecting wavelength intervals in spectral imaging applications

A PLS-bootstrap-VIP approach is proposed as a simple wavelength selection method, yet having the ability to identify relevant spectral intervals. This approach is particularly attractive for wavelength selection within hyperspectral images due to its simplicity and relatively low computational cost compared to more sophisticated interval search methods. The method was tested on four visible-NIR spectral imaging datasets taken from the polymer, oil and pulp and paper industries. The results were compared with those obtained using PLS regression coefficients as well as with two more sophisticated methods involving several metrics or search for wavelength intervals. It is shown that a small number of well defined relevant spectral intervals are identified with the proposed approach, providing easy spectral interpretation in agreement with more complex interval search methods. Before final use, fine adjustments to the VIP threshold may be tested to verify whether predictive power can be improved.