How to resize an MRI image data keeping the original field of view?

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I have few MRI datasets, where the dimension of the dataset is 320x640x16. First two dimensions are row and column and the last one is Coil dimension. I want to resize the row and column into 256x256x16, keeping the original Field of view. I tried the below code. But it make changes into the field of view and it cut the slices.
new_data = zeros([256,256,16]);
load brain.mat;
new_data(:,:,:) = raw_data(33:288, 193:448, :);

Answers (2)

Image Analyst
Image Analyst on 4 Aug 2022
First get one of the images then call imresize.
[rows, columns, numberOfSlices] = size(raw_data)
new_data = zeros(256, 256, numberOfSlices, class(raw_data));
for k = 1 : numberOfSlices
thisImage = raw_data(:, :, k);
new_data(:, :, k) = imresize(thisImage, [256, 256]);
end
  5 Comments
Image Analyst
Image Analyst on 4 Aug 2022
Edited: Image Analyst on 4 Aug 2022
Not sure where you got that weird looking image but this works fine
s = load('brain.mat');
raw_data = s.raw;
[rows, columns, numberOfSlices] = size(raw_data)
new_data = zeros(256, 256, numberOfSlices, class(raw_data));
for k = 1 : numberOfSlices
thisImage = raw_data(:, :, k);
subplot(2, 1, 1);
imshow(thisImage, [])
axis('on', 'image');
new_data(:, :, k) = imresize(thisImage, [256, 256]);
subplot(2, 1, 2);
imshow(new_data(:, :, k), [])
axis('on', 'image');
end
The original and resized images are shown below:
However you only put one 2-D image into the .mat file, not a 3-D image.

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Matthew Pepich
Matthew Pepich on 4 Aug 2022
I was too slow with my answer and @Image Analyst did it better, but here is another option that just samples the image. This works for displaying a thumbnail where interpolation is not important, but "imresize" is preferred if you need accuracy.
% Get your original image
C = imread('landOcean.jpg');
% Produce a scaled down image
scale = 0.10;
x = round( linspace( 1, size(C,1), size(C,1)*scale ) );
y = round( linspace( 1, size(C,2), size(C,2)*scale ) );
C2 = C(x, y, :);
% Display results
figure();
subplot(2,1,1);
image(C);
axis image;
title( sprintf('Size = %d x %d',size(C,[1 2])) )
subplot(2,1,2);
image(C2);
axis image;
title( sprintf('Size = %d x %d (Scaled to %g%%)',size(C2,[1 2]), 100*scale) )
  2 Comments
Matthew Pepich
Matthew Pepich on 4 Aug 2022
Would it still work to use "linspace" to generate even indices? Ignoring the display part of my solution, try just using this to produce your indices:
x = round( linspace( 1, size(raw_data,1), 256 ) );
y = round( linspace( 1, size(raw_data,2), 256 ) );
new_data = raw_data(x, y, :);

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