need to make a function which reads each pixel in a 2x2 block of an image

I have actually tried to divide my image into 2x2 blocks. After retreiving each block, have run a loop upto the total number of 2x2 blocks. Now , in each block, i need to call a function which is going to read all 4 pixels , one by one so that i can apply conditions accordingly..

Answer 1

[Titus Edelhofer]

Hi Ankita,

the simplest would be to loop on all blocks

A = ... % your image
lastRow = 2 * (floor(size(A,1)-1)/2);
lastCol = 2 * (floor(size(A,2)-1)/2);
for i=1:2:lastRow
  for j=1:2:lastCol
    yourBlock = A([i i+1], [j j+1]);
  end
end

There are probably more elegant ways to do the same, but that should be a good (and simple) start ... Titus