Nested dilations and erosions
	What does this operation do?
		• this is called an opening operation • http://www.dai.ed.ac.uk/HIPR2/open.htm
	You can clean up binary pictures by applying combinations of dilations and erosions Dilations, erosions, opening, and closing operations are known as morphological operations • see http://www.dai.ed.ac.uk/HIPR2/morops.htm