1. A method of increasing the probability of detecting at least one micro-calcification lesion in a mammogram, said method comprising the steps of: a. obtaining digital mammogram data by using an X-ray digital mammography system; b. calculating stochastic resonance noise with a processor by determining the stochastic resonance noise probability density function that does not increase the probability of false alarm and calculating the stochastic resonance noise data probability density function from a known probability density function for said digital mammogram data, wherein the stochastic resonance noise probability density function equals p n opt (n)=λδ(n−n 1 )+(1−λ)δ(n−n 2 ), with values n 1 and n 2 equal to two delta function locations having probabilities of λ and 1−λ respectively, where n 1 and n 2 denote two discrete vectors, λ denotes the probability of occurrence of said two vectors, and n is a randomization of said two discrete vectors added with the probabilities of λ and 1−λ, respectively; and c. adding said stochastic resonance noise to said digital mammogram data by using said processor, thereby improving the detection of said at least one micro-calcification lesion in the mammogram.