Image Coding
A measure that is important in transmitting pictures over a
communication system is "mutual information" defined as
I(X, Y) = H(X) - H(X/ Y) = H(Y) - H(Y/X)
This may be seen as the information transmitted:
H (X) is the information input and
H(X/Y) is the information about X, given that the received picture Y is known.
Then, if Y is totally correlated with X, H(X/Y) = 0, I(X/Y) = H(X)
If Y is independent of X, H(X/Y) = H(X), I(X/Y) = 0