Masking data of 4D images

Hi there,

I have a 3D binary mask and I would like to mask my 4D data. So basically I would like to keep the information of my 4D data in all the voxels corresponding to the mask.

Any idea how to do this?

Answer 1

[David Legland]

Hi Gina,

I suppose that you want to repeat the binary mask along the missing dimension of your 4D data, right?

One possibility could be the following:

mask4d = repmat(mask, 1, 1, 1, size(data, 4));
values = data(mask4d);

(This assumes that the three dimensions of the mask correspond to the first three dimension of the data).

[Gina Carts]

Yes, I want to repeat the mask along the 4th dimension to identify the non zero voxels. The rest will be zero.

I tried what you have suggested but I'm getting the following error at this line: values = data(mask4d);

My data are all positive numbers

Subscript indices must either be real positive integers or logicals.