what is var function in matlab?how does it works in image processing?

what is var function in matlab? how does it works in image processing?

[Matt J]

Shouldn't you know, if you've read

 >>doc var
 >>help var

Answer 1

[Image Analyst]

V = var(X) returns the variance of X for vectors. For matrices, var(X)is a row vector containing the variance of each column of X.For N-dimensional arrays, var operates along the first non-singleton dimension of X. The result V is an unbiased estimator of the variance of the population from which X is drawn, as long as X consists of independent, identically distributed samples.

It might possibly be used locally in image processing as an edge detector, or to determine the noise or SNR in an image.