[Image-SIG] Choosing arbitrary polygons

José Luis Gómez Dans josegomez@gmx.net
Thu, 18 Apr 2002 18:13:18 +0100

	I did post something on comp.lang.python earlier on today, and then 
realised that I hadn't checked PIL in a long long time. The main query 
was about developing (if none available) some software to do image 
processing interactively. One of the most important things that I need 
to do is to select arbitrary areas of an image (polygons), and then 
extract statistics off that. I'd like to be able to display an image, 
and then retrieve a list of tuples with the vertices of each polygon, 
which can then be used to select areas within a 2D Numeric array.

	The crop method does this, but only for rectangular areas. I was 
wondering whether I have missed something, and whether a more general 
polygon extraction routines is available.

	On the other hand, what would be the best way to do this using the 
mouse (and allowing zooming in and out of the image, etc.)?

	Many thanks
José L Gómez Dans			PhD student
Tel: +44 114 222 5582			Radar & Communications Group
FAX; +44 870 132 2990			Department of Electronic Engineering
					University of Sheffield UK