;+
; NAME: tuneregister
; PURPOSE:
; 	Tune up image registration.
;
; 	Takes an already-registered stack of images (possibly done by hand)
; 	then cuts out a subregion in it and runs subreg on that subregion.
;
; INPUTS:
; KEYWORDS:
; OUTPUTS:
;
; HISTORY:
; 	Began 2005-11-13 11:20:44 by Marshall Perrin 
;-

function tuneregister,imgs,center=center,boxsize=boxsize,$
	_extra=_extra,px=px,py=py

	if ~(keyword_set(center)) then begin
		findmaxstar,imgs[*,*,0],mx,my
	endif else begin
		mx=center[0]
		my=center[1]
	endelse
	if ~(keyword_set(boxsize)) then boxsize=256
	message,/info,"Cutting out a subregion of size "+strc(boxsize)+" to fine tune."

	imgs2 = imgs[mx-boxsize:mx+boxsize-1,my-boxsize:my+boxsize-1,*]

	message,/info,"Fine tuning registration..."
	subreg,imgs2[*,*,0],imgs2,shifts,_extra=_extra

	if arg_present(px) then px -=shifts[0,*]
	if arg_present(py) then py -=shifts[1,*]


	return,shifts

end