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Zoe
0

How to loop through several tiff images and reshape them

Asked by Zoe
on 26 Sep 2017
Latest activity Edited by Jan
on 26 Sep 2017
Accepted Answer by Jan
I have 6 images which all have the same number of rows and columns (Basically 6 optical bands of one remote sensing imagery). The original size of each image is 1455*1464. I want to loop through them, then reshape each of them into a vector with 1455*1464 (=2130120) rows and 1 column. So far, I only know how to manually load images and do something to them, but don't understand loop. I appreciate any help! Thank you! The code looks like this:
for i = 1:1455
for j = 1:1464
for h = 1:6
A(1,h) = reshape(image(i,j,h), 2130120,6)
end
end
end
I do not think it is correct. Every time I run it, it gives me the error message: Error using reshape To RESHAPE the number of elements must not change.

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1 Answer

Answer by Jan
on 26 Sep 2017
Edited by Jan
on 26 Sep 2017
 Accepted Answer

What is you input? Does "image" contain an [1455 x 1464 x 6] array? If so, use:
img = reshape(img, 1455*1464, 6);
to get a [2130120 x 6] matrix. You do not need loops to do this.
With loops you can omit the reshape:
A = zeros(2130120, 6); % Pre-allocate!!!
for i = 1:1455
k = 0;
for j = 1:1464
for h = 1:6
k = k + 1;
A(k, h) = img(i,j,h);
end
end
end
Or use:
k = i + (j - 1) * 1455;

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