creating a custom spectral library for hyperspectral support package spectralMatch

I don't know why you folks have made this so ridiculously complicated, but I haven't been able to figure out how to create a customized spectral library given a set of library spectra (with associated wavelength values and names of the spectra) for use with your spectralMatch routine. Thanks.

Answer 1

[Parth Parikh]

Hi William,

Thanks for trying out the spectralMatch function. It would be nice if you can provide more details by sharing the customized spectral library. Further I would like to know if you are facing any failures or is it difficult to understand the spectralMatch functionality ?

SpectralMatch does following things before matching the spectra:

• Continuum Removal: Continuum Removal is used to normalize reflectance spectra so that one can compare individual absorption features from a common baseline. The continuum is a convex hull fit over the top of a spectrum using straight-line segments that connect local spectra maxima.
• Finding Common wavelength bandwidth: Most of the time the wavelength range of the hypercube and that of the library is different. As a result, we need to calculate the common wavelength range or bandwidth prior to matching.
• Resample Spectra: Often the hypercube reflectance spectra and library reflectance spectra will be having different sampling wavelengths. Therefore it is necessary to resample the hypercube reflectance spectra according to the library reflectance spectra before matching.

You can pass custom spectral library to spectralMatch function, as it only look for wavelength and reflectance values. Here customLib is structure containing wavelength and reflectance values for a given material.

score = spectralMatch(customLib, hcube);

Take a look at the spectralMatch doc for more details:

Let me know if that helps.