MATLAB: How to load AVIRIS datasets

avirishyperspectral imagingMATLAB

Hi everyone, I have downloaded some AVIRIS datasets from https://aviris.jpl.nasa.gov/dataportal/ and have been trying to have a look at them in MATLAB. The images I obtained, however, are strange, and don't look anything like the data preview from the page. I have looked at a few resources, including
https://kr.mathworks.com/matlabcentral/answers/242269-how-to-read-aviris-hyperspectral-image
http://www.ehu.eus/ccwintco/uploads/d/dc/LoadHypercubesMatlab.pdf
https://uk.mathworks.com/matlabcentral/answers/461044-how-to-convert-the-raw-hyperspectral-image-hawaii-or-yellowstone-into-mat-file
but still have not found a solution. Can anyone please shed some light on what I am doing wrong? Here is my code:
fileNameD = 'D:\Data\AVIRIS\f160620t01p00r06rdn_b\f160620t01p00r06rdn_b\f160620t01p00r06rdn_b_sc01_ort_img'; 
fileNameH = [fileNameD,'.hdr'];
GainFile  = 'D:\Data\AVIRIS\f160620t01p00r06rdn_b\f160620t01p00r06rdn_b\f160620t01p00r06rdn_b.gain';
gainvals = importdata(GainFile);
info = envihdrread(fileNameH); %info.data_type=2  so 16-bit signed integer
X = multibandread(fileNameD,[info.lines,info.samples,info.bands],'int16',info.header_offset,info.interleave,info.byte_order,...
                  {'Row','Range',[4000 1 6000]}, {'Column','Range',[1 1 info.samples]}); 
              
X1 = bsxfun(@rdivide,double(X), reshape(gainvals(:,1),[1 1 length(gainvals(:,1))])); %divide by the gain to get radiance
and here is the resulting image I obtain when I plot RGB (i.e. figure, imagesc((X1(:,:,[31,20,10]))))
versus the RGB image preview @ https://aviris.jpl.nasa.gov/aviris_locator/y16_RGB/f160620t01p00r06_sc01_RGB.jpeg (note this shows the full image, while the above is only a subset)
It bears some semblance to the image but this does not seem right. I've also plotted the spectra for some pixels and it also looks strange, e.g.
I've tried this on 4 different radiance datasets so far, as well as reflectance datasets and obtained similar results. Any suggestions will be much appreciated, thank you!

Best Answer

You can use the hypercube(__) function to read AVIRIS image .hdr files.
% Read the AVIRIS image (specify your image file name here)
hCube = hypercube('jasperRidge2_R198.hdr');
% Compute RGB, CIR, and falsecolored image
rgbImg = colorize(hCube, 'method', 'rgb', 'ContrastStretching', true);
cirImg = colorize(hCube, 'method', 'cir', 'ContrastStretching', true);
fcImg = colorize(hCube, 'method', 'falsecolored', 'ContrastStretching', true);
% Visualize results
figure
tiledlayout(1, 3)
nexttile
imagesc(rgbImg)
axis image off
title('RGB image')
nexttile
imagesc(cirImg)
axis image off
title('CIR image')
nexttile
imagesc(fcImg)
axis image off
title('False-colored image')
Note: All the above mentioned fetures come under Image Processing Toolbox's Hyperspectral Imaging Library support package, and can be downloaded from here.
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