function nimg = SaltPepperNoise(img, p3)

if nargin < 2
    p3 = 0.05;
end
nimg = img;
sizeA = size(img);
x = rand(sizeA);
nimg(x < p3/2) = 0; % valor minimo
nimg(x >= p3/2 & x < p3) = 255; % valor maximo (saturado)