What does it mean by DN in salt-pepper noise?

Salt noise: DN = maximum possible. indicates that salt noise shows up as pixels with the largest possible pixel values (e.g. 255 if the picture is a grey scale picture represented by pixel in the [0-255] range), and that. Pepper noise: DN = minimum possible.

1. What do you mean by salt and pepper noise?
2. What is Gaussian noise and salt and pepper noise?
3. What causes salt pepper noise?
4. Which filter is best to remove salt and pepper noise?

What do you mean by salt and pepper noise?

Salt and pepper noise refers to a wide variety of processes that result in the same basic image degradation: only a few pixels are noisy, but they are very noisy. The effect is similar to sprinkling white and black dots—salt and pepper—on the image.

What is Gaussian noise and salt and pepper noise?

Noise Reduction

For instance, in Gaussian noise, a normally distributed random value is added to each pixel (fig. 1b). On the other hand, salt-‐and-‐pepper noise describes a situation where random pixels get replaced by extremely dark or bright values (fig. 1c).

What causes salt pepper noise?

Salt and pepper noise is an impulse type of noise in images. This noise is generally caused by errors in data transmission, failure in memory cell or analog-to-digital converter errors. It takes the form of randomly occurring white and black pixels, which can significantly deteriorate the quality of an image.

Which filter is best to remove salt and pepper noise?

The standard median filter is a typical nonlinear filtering method with a simple idea and fast processing, which is most suitable for processing impulse noise such as salt and pepper noise.