;------------------------------------------------------------------
; KOAMP : Amplituden-Koregistrierung
; (C)23.9.97 by Andreas Reigber
;------------------------------------------------------------------
; Amplitude Koregistration using FFTs. Precision 1 Pixel 
; 
; Usage:
; res = koamp(s1,s2)
;  	s1, s2 : Two amplitude images (floating point)
;     res[0] : x offset between the images
;     res[1] : y offset between the images
;------------------------------------------------------------------
; This software has been released under the terms of the GNU Public
; license. See http://www.gnu.org/copyleft/gpl.html for details.
;------------------------------------------------------------------

;
function koamp,s1,s2
	sizx = (size(s1))[1]
	sizy = (size(s1))[2]
	aux=max(abs(fft(fft(abs(s1),-1)*conj(fft(abs(s2),-1)),1)),pos)
	xoff = pos mod sizx
	yoff = pos  /  sizx
	if xoff gt sizx / 2 then xoff = xoff - sizx
	if yoff gt sizy / 2 then yoff = yoff - sizy
	return,[xoff,yoff]
end