Double Poppies

This is our first summer in our new home.  The previous owners obviously sowed some double 'peony?' poppies.  They are absolutely beautiful, can't stop admiring them, and I wonder if it's possible to collect the seed from this variety so that I can grow them next year or will I have to purchase them?  I have only seen pictures matching my variety on American websites and haven't seen them for sale by any UK companies.  Any suggestions gratefully received.