I have loaded the mat files of Pavia on Matlab but I am unable to go further. I tried imshow(Pavia) & imshow(pavia, []) but i am able to proceed. Please help me out.
Dear Shrish Bajpai
As Ahmet says, "imshow" can only display single-band (or 3-band, RGB) images while hyperspectral images have usually more than 100 bands, e.g. Pavia University data set has 103 bands (610x340-pixel bands).
In order to visualize such data, use one of the following methods:
- implay
>> implay(mat2gray(pavia))
- or, write a piece of code like this:
Nb = size(pavia,3);
for nb=1:Nb
imshow(pavia(:,:,nb), [])
title(['band number = ', num2str(nb)])
pause % hit a key to see the next band
end
- False-color RGB
[Nx, Ny, Nb] = size(pavia);
[~, PCs] = princomp(reshape(pavia, [], Nb));
falseColorPavia = mat2gray(reshape(PCs(:,1:3), Nx, Ny, 3));
imshow(falseColorPavia)
Imshow can not handle multi-band images. For starters, try displaying bands one-by-one.
Dear Shrish Bajpai
As Ahmet says, "imshow" can only display single-band (or 3-band, RGB) images while hyperspectral images have usually more than 100 bands, e.g. Pavia University data set has 103 bands (610x340-pixel bands).
In order to visualize such data, use one of the following methods:
- implay
>> implay(mat2gray(pavia))
- or, write a piece of code like this:
Nb = size(pavia,3);
for nb=1:Nb
imshow(pavia(:,:,nb), [])
title(['band number = ', num2str(nb)])
pause % hit a key to see the next band
end
- False-color RGB
[Nx, Ny, Nb] = size(pavia);
[~, PCs] = princomp(reshape(pavia, [], Nb));
falseColorPavia = mat2gray(reshape(PCs(:,1:3), Nx, Ny, 3));
imshow(falseColorPavia)
when you load the mat file,the variable is a m*n*k matrix. you can change this matrix to 2-Dimention matrix by the following code:
Band1=variable(:,:,1); Band2=Variable(:,:,2)......Bandk=variable(:,:,k);
Then each variable is a gray scale picture you can use imshow to display.
If you want to show the true color/false color picture,
you can set the Variable(band1 to bandk) as the R G B band .Any combinations is ok.
Hope this can help you.
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