Increase one of the dimensions of an array

I have a 190x190x20 array with intensity values of medical images (nifti). The resolution is (1mm, 1mm, 2mm), and I would like to have the same resolution in all directions. In other words, I want 40 pages instead of 20 pages.

Is there any way to increase the number of pages or increase the resolution in one direction? I have looked at interpolation, but I'm not sure if it will work in my case.

Greatful for any ideas.

[Stephen23]

"In other words, I want 40 pages instead of 20 pages."

You are making an off-by-one error. Consider:

V = 1:4

V = 1×4

1 2 3 4

W = 1:0.5:4

W = 1×7

1.0000 1.5000 2.0000 2.5000 3.0000 3.5000 4.0000

W has twice the resolution of V, but does it have twice the number of elements in it?

" I have looked at interpolation, but I'm not sure if it will work in my case."

Probably: what you describe is some kind of interpolation (using what method is another question entirely).

What have you tried so far?

[Sebastian Dahl Sandbu]

I see, thanks for the explanation.

So for mye array A, I have tried interp3(A), but that will increase the resolution in all dimension. I did also try the following, but without success.

[X, Y, Z] = size(A);
[Xq,Yq,Zq] = meshgrid(1:1:190,1:1:190,1:.5:39.5);

B = interp3(X, Y, Z, A, Xq, Yq, Zq);

Answer 1

[Image Analyst]

Try interp3

help interp3

Something like (untested)

[rows, columns, slices] = size(img)
z = linspace(1, slices, 2 * slices); % Need twice as many slices as the original.
[X, Y, Z] = meshgrid(1:columns, 1:rows, z);
img2 = interp3(img, X, Y, Z);

[Sebastian Dahl Sandbu]

Thanks!