What is the use of repmat in the following program?

What is the use of repmat in the following program?

i=I;
[ir ic]=size(I);
if ir ~=512 && ic~=512
   I=repmat(I,[1 2]);
end

Answer 1

[Jan]

If none of the dimensions of I equal 512 (for some reason) it is repeated and the copied matrix is added horizontally to I.

i.e. the following should produce the same output

if ~any( size(I)==512 )
   I=horzcat(I,I);
end

[Pooja]

By doing this will it affect the input image?Any data loss?

[Jan]

As I said, the matrix I (or image if you will) will be duplicated and the results concatenated if none of the input dimensions equal "512". In that case, the code does affect the image - you end up with an image of double width where left half and right half are identical. Prior to this step a copy of the image is made (i=I;). No data will be lost.

Anyway, the action based on the condition in the if-statement does seem slightly weird to me. Are you sure the code makes sense in a broader scope?