Submit a Story  :  IRAF Links  :  Past Polls  :  Calendar  :  Advanced Search  
     iraf.net
  About iraf.net
Downloads
Docs
Projects
FAQ
Support
Forums
Links
Email Contact Us  
Privacy Policy
User Functions
Username:

Password:

Don't have an account yet? Sign up as a New User
What's New
STORIES
No new stories

COMMENTS last 48 hrs
No new comments
 Forum FAQForum FAQ   Forum SearchForum Search   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

xregister question

 
Post new topic   Reply to topic    iraf.net Forum Index -> General IRAF
View previous topic :: View next topic  
Author Message
AndrewS
Active IRAF User


Joined: 10 Oct 2010
Posts: 33
Location: Galway Ireland
PostPosted: Thu Jul 14, 2011 2:20 pm    Post subject: xregister question Reply with quote
Hello

I am trying to use xregister to register dithered frames... The max off-set of any frame to the reference frame being used is about 15pixels in either x or y..
I have had to use xregister in several passes in order to get my images fully registered - that is to say although with each pass, xregister shifts my image in the right direction, it does not shift it far enough so I have to put this partially registered frame back into xregister so that it will get shifted a little closer , and so on until finally the image becomes registered.... the following lines of code will clarify what i mean:

Code:


xregister ("@to_register.txt",
"ref_frame.fits", "[*,*]", "shifts1.db", output="@to_register.txt//_pass1", databasefmt=yes, append=no, records="",
coords="", xlag=0, ylag=0, dxlag=0, dylag=0, background="none", border=INDEF,
loreject=INDEF, hireject=INDEF, apodize=0., filter="none",
correlation="discrete", xwindow=11, ywindow=11, function="centroid", xcbox=10,
ycbox=10, interp_type="linear", boundary_typ="nearest", constant=0.,
interactive=no, verbose=yes, graphics="stdgraph", display="stdimage",
gcommands="", icommands="")

xregister ("@to_register.txt//_pass1",
"ref_frame.fits", "[*,*]", "shifts2.db", output="@to_register.txt//_pass2", databasefmt=yes, append=no, records="",
coords="", xlag=0, ylag=0, dxlag=0, dylag=0, background="none", border=INDEF,
loreject=INDEF, hireject=INDEF, apodize=0., filter="none",
correlation="discrete", xwindow=11, ywindow=11, function="centroid", xcbox=10,
ycbox=10, interp_type="linear", boundary_typ="nearest", constant=0.,
interactive=no, verbose=yes, graphics="stdgraph", display="stdimage",
gcommands="", icommands="")

xregister ("@to_register.txt_pass2",
"ref_frame.fits", "[*,*]", "shifts3.db", output="@to_register.txt//_pass3", databasefmt=yes, append=no, records="",
coords="", xlag=0, ylag=0, dxlag=0, dylag=0, background="none", border=INDEF,
loreject=INDEF, hireject=INDEF, apodize=0., filter="none",
correlation="discrete", xwindow=11, ywindow=11, function="centroid", xcbox=10,
ycbox=10, interp_type="linear", boundary_typ="nearest", constant=0.,
interactive=no, verbose=yes, graphics="stdgraph", display="stdimage",
gcommands="", icommands="")


#...... and so on until //_passi at which point the images will be registered


and the parameters I used are those shown in the above code....
Could I alter parameters so that I only have to run frames through xregister one time?

Also note, there is partial fringing in both the ref_image and images to be registered...the fringe pattern is the same in both the ref_image and the images to be registered... So I think one possible reason for the number of passes I had to use is that xregister was conflicted as to whether it should keep the fringe pattern aligned or shift everything so that the astronomical objects are aligned instead....but I recall trying to use xregister on non-fringed images and I think the problem of needing several passes happened there too..
Final point: The quality of the registered images is significantly degraded from those of the initial images and this time I suspect that the fact that there was a fringe pattern may have caused this.....

comments on all the points raised above are appreciated
Back to top
View user's profile Send private message
robsteele49



Joined: 03 May 2010
Posts: 10
Location: Frazier Park
PostPosted: Thu Jul 14, 2011 11:32 pm    Post subject: Reply with quote
I had pretty good luck with increasing the window size to allow for one pass, but I would specify a small region that I was interested in aligning. Maybe that would help?
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    iraf.net Forum Index -> General IRAF All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2009 phpBB Group
 Copyright © 2005-2011 iraf.net
 All trademarks and copyrights on this page are owned by their respective owners.		 Powered By Geeklog 
Created this page in 0.09 seconds