How I can zero pad a 14*14 matrix to 682*577 dimension?

Hi,

I want to zero pad a matrix with 14*14 dimension to have 682*577 dimensions. I want to data be in center of the new matrix. How I can do it?

I used this

D = padarray(h,[334 281],0,'both');  

but I get a matrix with 682*576 dimensions. What's wrong?

[Matt J]

Maybe h is zero?

[mohammad nemat]

no it's not zero .and i have problem with this dimension .

[Matt J]

The dimensions seem fine, since

[334 281]*2+14

ans = 1×2

682 576

And, we can check right here and now that if h is not zero, it works:

D = padarray(ones(14),[334 281],0,'both');
imshow(D)

Answer 1

[Image Analyst]

Try this trick

h = ones(14, 14); % Original matrix is 14 x 14
% Pad it out with 334 rows top and bottom,
% and 281 columns left and right.
D = padarray(h, [334, 281], 0, 'both');
whos D  % Originally 682x576
% Not the size we want yet.  We want 682x577
% Here comes the "trick" to expand out the lower right corner with zeros.
D(end, 577) = 0;
whos D  % Now 682x577

% Alternatively you can call padarray() with the 'pre' and 'post' option if you want to use different amounts of padding on each side.

[mohammad nemat]

hi . thanks for your response. my h file in double like this picture when i use this code my D matrix is zero.

[Walter Roberson]

That appears to be a 14 x 13 matrix, at least from what we can see, but your post said you were working with a 14 x 14 matrix?

[Image Analyst]

I don't know how that could be. That matrix is not padded with zeros at all.

Attach your h matrix in a .mat file with the paper clip icon.

save('answers.mat', 'h');

Also attach the actual code you used.

[mohammad nemat]

thanks it's ok.

Answer 2

[Walter Roberson]

but I get a matrix with 682*576 dimensions. What's wrong?

You started with a matrix with even dimension, 14 x 14. You used padarray() with 'both'. That puts the same amount of space on the left and right, so the number of columns is going to be N + 14 + N = (2*N) + 14 for some integer N. But that is always going to be an even number. Therefore you cannot use padarray() 'both' to turn an array with even dimension into an array with odd dimension in a single step.