# Spectral Resampling from hyperspectral to multispectral

14 views (last 30 days)
Nandita Sarkar on 2 Jun 2022
Answered: Bjorn Gustavsson on 4 Jun 2022
Can anyone help me to do this spectral resampling of hyperspectral image to multispectral image using matlab. Please anyone help me to do this.
Image Analyst on 3 Jun 2022
OK, if youi don't like my Answer/solution below you can just scan every pixel and resample using interp1d.

Image Analyst on 2 Jun 2022
How many wavelength bands are you starting with and how many do you think you want to end up with?
Do they need to be actual wavelength bands? If you want you could use pca (demo attached) and use the PC's as the new images.

Bjorn Gustavsson on 4 Jun 2022
If you have a hyper-spectral image, I_hs, on the format [n_y x n_x x n_lambda] and you want to reduce the number of wavelength-channels you might do something like this (hoofed live-edited and no-tested):
function I_ms = hyper2multi(I_hs,w_lambda)
sz_Ihs = size(I_hs);
sz_w = size(w_lambda);
I_ms = zeros([sz_Ihs(1:2),sz_w(2)]);
for i_lout = 1:sz_w(2)
for i_lin = 1:sz_Ihs(3)
I_ms(:,:,i_lout) = I_ms(:,:,i_lout) + I_hs(:,:,i_lin)*w_lambda(i_lin,i_lout);
end
end
end
where w_lambda should be an [n_lambda x n_multi] array with weighting-factors for the spectral response you want in your multi-spectral image (all zeros except a single 1 in a column if you want to extract a single wavelength-channel)
HTH

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