how to add 4 db and 6db gaussian, salt& pepper,speckle noises in images

how to add 4 db and 6db gaussian, salt& pepper,speckle noises in images

Answer 1

[Walter Roberson]

imnoise()

[deepesh kaushik]

please give complete algorithm

[Walter Roberson]

You can find the algorithm in Wikipedia or the like. The definition of those types of noise effectively is their algorithm.