Common Types of Noise

Noise is just another function that is combined with the original function to get a new function

I’(x,y) = I(x,y) + n(x,y)

n(x,y) - noise

Salt and pepper noise: random occurrences of black and white pixels

Impulse noise: random occurrence of white pixels

Gaussian noise: variation in intensity drawn from a Gaussian normal distribution

Make Gaussian noise

>> noise = randn(size(im)) .*sigma;

Output = im + noise;

28. Image Difference Demo

Diff = dol - bi; // 20 - 56 = 0

Absdiff = abs(bi - dol); // |20-56| = 36

% better: use image package

pk g load image;

Diff_img = imabsdiff(dol, bi);

imshow(diff_img);