How to pad zeros?

I have an image whose size is 1023*1023. I want to make this image as 1024*1024 by zero padding.

A = zeros (1023,1);
I1 = horzcat (I1,A);
I2 = horzcat (I2,A);
B = zeros (1,1024);
I1 = vertcat (I1,B);
I2 = vertcat (I2,B);

Is this right?

Answer 1

[José-Luis]

If you want to add a dark edge (that's what the zeros will be), at the bottom and to the right:

load mandrill
[m n] = size(X); %in your case it will be [1023 1023]
X = [ [X;zeros(1,n)] zeros(m+1,1)];

At the top and to the left:

load mandrill
[m n] = size(X); %in your case it will be [1023 1023]
X = [ zeros(m+1,1) [zeros(1,n);X] ];

Plus the two other alternatives, with the same principle:

 X = [[zeros(1,n);X] zeros(m+1,1)];
 X = [ zeros(m,1) [X;zeros(1,n+1)] ];

[Andrei Bobrov]

xout = zeros(size(X)+1);
xout(1:end-1,1:end-1) = X;

Answer 2

[Image Analyst]

You can use the padarray() function. It's meant for doing exactly this.

paddedArray = padarray(originalArray, [1 1]);

[Sabarinathan Vadivelu]

Here I'm getting a size of 1025 X 1025.

[Dishant Arora]

paddedArray = padarray(originalArray, [1 1],'post');

[Image Analyst]

Sorry - I misread and thought you wanted an extra zero all the way around. Thanks, Dishant, for the correction.