How do I pad with zeros?

Rather than extracting the last row from the top and bottom of X_proj_corrected, I want to add 100 rows of zeros to either the top or bottom of X_proj_corrected using padarray function?

%Extract last row from X_proj_corrected sinogram from top and bottom
X_proj_corrected_padded100 = [X_proj_corrected(1,:); X_proj_corrected];
X_proj_corrected_padded100 = [X_proj_corrected; X_proj_corrected (size(X_proj_corrected,1),:)];


%Using last row from top and bottom 100 rows padded top and bottom using IPT
X_proj_corrected_padded100 = padarray(X_proj_corrected,100,'replicate','both');
figure
imagesc(X_proj_corrected_padded100)

[David Hill]

Hard to understand your description. Please provide a simple example of what you want to do. It should be quite easy.

[Ryan]

Hi David, rather than extracting the last row from the top and bottom of X_proj_corrected, I want to add 100 rows of zeros to either the top or bottom of X_proj_corrected using padarray function? Thanks.

Answer 1

[Cris LaPierre]

To pad with 100 rows of zeros, do the following

% to add to the top
X_proj_corrected = padarray(X_proj_corrected,100,'pre');

% to add to the bottom
X_proj_corrected = padarray(X_proj_corrected,100,'post');

[Ryan]

Great! Thanks Cris, now working as expected.