Save the ds9 region parameters in a frame. The data are stored in 3 files, using 3 coordinate systems:

% ds9_region_saver --help    

Usage: ds9_region_saver N 
arg1 - run in debug mode (Y/N)

The file that are saved: 
   Saved_Coordinates.fk5.reg       = ra,dec in degrees,degrees  
   Saved_Coordinates.image.reg     = x,y in pixels 
   Saved_Coordinates.physical.reg   = x,y in pixels 

% cat Saved_Coordinates.fk5.reg  
# Region file format: DS9 version 4.1
global color=green dashlist=8 3 width=1 font="helvetica 10 normal roman" select=1 highlite=1 dash=0 fixed=0 edit=1 move=1 delete=1 include=1 source=1
fk5
circle(161.9569026,12.5837073,36.303")

% cat Saved_Coordinates.image.reg  
# Region file format: DS9 version 4.1
global color=green dashlist=8 3 width=1 font="helvetica 10 normal roman" select=1 highlite=1 dash=0 fixed=0 edit=1 move=1 delete=1 include=1 source=1
image
circle(990,1063,26.811873)

% cat Saved_Coordinates.physical.reg  
# Region file format: DS9 version 4.1
global color=green dashlist=8 3 width=1 font="helvetica 10 normal roman" select=1 highlite=1 dash=0 fixed=0 edit=1 move=1 delete=1 include=1 source=1
physical
circle(990,1063,26.811873)