I am having a hard time understanding what `scipy.cluster.vq` really does!! 

On Wikipedia it says `Clustering` can be used to divide a digital image into distinct regions for border detection or object recognition.  

on other sites and books it says we can use `clustering` methods for clustering images for finding groups of similar images.  

AS i am interested in image processing ,I really need to fully understand what `clustering` is .

So  

Can anyone show me simple examples about using `scipy.cluster.vq` with images??