MATLAB inverse function (doesn't allow bigger than 255)

Hey there ,

I have an image and i want to use an inverse function on it with this formula.

but i have a problem after i write the code in loop.MATLAB doesn't allow the number that bigger than 255 and always give me a result as 1 (255/255).My code is here :

for i= 1 : 1:2

      for j = 1 : 2
          yinv(i,j) = ((255 - ylpf(i,j))^2 ) / 255;
      end
  end

Answer 1

[Walter Roberson]

for i= 1 : 1:2
    for j = 1 : 2
        yinv(i,j) = uint8( (double(255 - ylpf(i,j))^2 ) / 255 );
    end
end

[Fabio Corres]

Thank you it works