function output = nearest(input)
[x,y]=size(input);
output = repmat(uint8(0),x*2,y*2);
[newwidth,newheight]=size(output);
for i=1:y
    for j=1:x
        xloc = round ((j * (newwidth+1)) / (x+1));
        yloc = round ((i * (newheight+1)) / (y+1));
        output(xloc,yloc) = input(j,i);
    end
end

%# Initializations:

scale = [2 2];              %# The resolution scale factors: [rows columns]
oldSize = size(inputImage);                   %# Get the size of your image
newSize = max(floor(scale.*oldSize(1:2)),1);  %# Compute the new image size

%# Compute an upsampled set of indices:

rowIndex = min(round(((1:newSize(1))-0.5)./scale(1)+0.5),oldSize(1));
colIndex = min(round(((1:newSize(2))-0.5)./scale(2)+0.5),oldSize(2));

%# Index old image to get new image:

outputImage = inputImage(rowIndex,colIndex,:);

newSize = max(floor(scale.*oldSize(1:2)),1);

rowIndex = min(round(((1:newSize(1))-0.5)./scale(1)+0.5),oldSize(1));
colIndex = min(round(((1:newSize(2))-0.5)./scale(2)+0.5),oldSize(2));

outputImage = inputImage(rowIndex,colIndex,:);

1           c         1                 scaleC*c
+-----------+ 1       +----------------------+ 1
|    |      |         |        |             |
|----o      |   <===  |        |             |
|  (ii,jj)  |         |--------o             |
+-----------+ r       |      (i,j)           |
  inputImage          |                      |
                      |                      |
                      +----------------------+ scaleR*r
                            ouputImage

Note: I am using matrix notation (row/col), so:
  i ranges on [1,scaleR*r] , and j on [1,scaleC*c]
  and ii on [1,r], jj on [1,c]

x-minX      y-minY
--------- = ---------
maxX-minX   maxY-minY

jj = (j-1)*(c-1)/(scaleC*c-1) + 1
ii = (i-1)*(r-1)/(scaleR*r-1) + 1

% read a sample image
inputI = imread('coins.png');
[r c] = size(inputI);
scale = [2 2];        % you could scale each dimension differently

outputI = zeros(scale(1)*r,scale(2)*c, class(inputI));

for i=1:scale(1)*r
 for j=1:scale(2)*c
  % map from output image location to input image location
  ii = round( (i-1)*(r-1)/(scale(1)*r-1)+1 );
  jj = round( (j-1)*(c-1)/(scale(2)*c-1)+1 );

  % assign value
  outputI(i,j) = inputI(ii,jj);
 end
end
figure(1), imshow(inputI)
figure(2), imshow(outputI)

output = imresize(input,size(input)*2,'nearest');

output = imresize(input,2,'nearest');

xloc = (j * (newwidth+1)) / (x+1);
yloc = (i * (newheight+1)) / (y+1);