Repeat elements in a 2D vector

I am trying to hardcode the upsampling of an image. The problem I am having is trying to do it in a loop. It seems impossible.Here is what I did.

Image = imread('grayscale.jpg');
%imshow(Image);
% Downsampling
[row, col] = size(Image);
Downimage = Image(1:2:row,1:2:col);
%imshow(Downimage);
%Upsampling
newrow = row*2;
newcol = col*2;
Upimage = zeros(newrow,newcol);
for r = 1:2:newrow
  for c = 1:2:newcol
    Upimage(r,c) = Downimage(r,c;
    Upimage(r+1,c+1) = Downimage;
  end
end
%Upimage = reshape([Downimage ; Downimage],1,[]);
%Upimage = repmat(Downimage, 2, 1);
imshow(Upimage);

Now I realize that for the loop to work it needs parameters beside the Downimage in the loop, but I can's seem to make it work due to the downimage being of the shorter size then the upimage. P.S I cant use imresize...I have to hardcode it

Answer 1

[dpb]

I'm no image processing guru, but look at

doc filter2

Mayhaps there a specific equivalent for image reconstruction in the appropriate toolbox'en the which of I haveth not...

Answer 2

[Jos (10584)]

OutImage = imresize(InImage, 2, 'nearest')

[Junaid Pirzada]

I cant use imresize

[dpb]

Why not?

[Jos (10584)]

You can also use

    OutImage = kron(InImage,ones(2))

[Junaid Pirzada]

I cant because the instructor wanted us to make a code that does this, but imresize does that easily...I dont think she would accept...@Jos will try using kron...I used it before it just displayed two images joined beside each other...will try using your one.