how to filter a image fits with a ds9 region file

- ftools
see
http://www-utheal.phys.s.u-tokyo.ac.jp/~yuasa/wiki/index.php/fitsイメージをregion_fileでフィルタリングしたい

ftimgcalc output.img 'regfilter("regionfile.reg",A.P1,A.P2)? A:0' a=input.img

- ciao
http://cxc.harvard.edu/ciao/ahelp/dmfiltering.html
I am not sure if this is works for general fits image.

http://cxc.harvard.edu/ciao/threads/radial_profile/