replacement of for loop in matlab

 for i=1:size(img,1)
  for j=1:size(img,2)
  if img(i,j)<=25
   img(i,j)=255;
  end
 end
end
can anyone please tell me about the replacement of this piece of code in just one line..? I know it can be replaced with one line, but i am not able to it correctly....

Answer 1

[Andrei Bobrov]

img(img <= 25) = 255

[Khawaja Asim]

thanku dear... :)