> I have a basic question. I am trying to create a binary mask for each of > our individual subject brains. I want to specify particular coordinates and > make them 0 and the rest 1s, assuming if I have a 2x3x5 matrix, I want to > make say 1x1:2x1:4 all 1s and the rest zeros. I am not sure if this is even > possible. It's not possible via the user interface, but if you are using SPM5, then it should involve a little bit of simple coding. P = spm_select(1,'nifti'); % Select an image Ni = nifti(P); % NIfTI handle for input image No = Ni; % Copy header to output image No.dat.fname = 'mask.img'; % Output filename No.dat.dtype = 'UINT8'; % Only a binary image, so 8-bit shoud be fine No.dat.scl_slope = 1/255; % Scalefactor so that a value of 1 is saved as 255 No.dat.scl_inter = 0; % Make sure the intercept is 0 No.descrip = 'Binary Mask'; % Some info about the file % The data to be written mask = ones(size(No.dat)); mask(1,1:2,1:4) = 0; create(No); % Write the header No.dat(:,:,:,:,:,:) = mask; % Write the data Best regards, -John