how to find threshold

I have calculated the variance of an image.now i need to classify the pixels as foreground when the variance is more than a threshold ,otherwise it is classified as background pixel.how to select this threshold

Answer 1

[Image Analyst]

It doesn't make sense to do what you said globally - just think about it.

There are several ways to do it locally adaptive: blockproc(), stdfilt(), nlfilter(), nested for loops, etc.

I show two of these in the demo attached below.

[Sapam Jaya]

it must b local variance..thnx a lot