How to load AVIRIS datasets

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!

Answer 1

[Subhadeep Koley]

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.

[Cheryl S]

Hello, thanks very much for the prompt response. I downloaded the library and tried the function "hypercube" on multiple images, but all cases it gives the following error:

Error using enviinfo (line 54)

File type number: char not supported.

[Subhadeep Koley]

@Cheryl S In my end, I am able to load the "f160620t01p00r06rdn_b_sc01_ort_img.hdr" image using hypercube(__) without any error.

Therefore, I suspect you have one local function in the name of "enviinfo.m", which is conflicting with the Hyperspectral Imaging Library's own enviinfo(__) function.

Rename or delete your local "enviinfo.m" function and then try again.

[Cheryl S]

Oh, you're right, I did as you suggested and it works now! I also combined enviinfo with multibandread to extract only a subset of the image and it works as well! Must be an issue with my original enviinfo.m file. Thank you very much for your help!