;+
; NAME:  HIMCUT
; PURPOSE:
; 	Like 'IMCUT', cut out a subregion from an image, and update FITS header.
;
; 	Very similar to HEXTRACT, but with different arguments
;
; INPUTS:
; KEYWORDS:
;	/center		use center
;	/method2	different coords computation, good for getting out odd-sized
;				boxes. See code
; OUTPUTS:
;
; HISTORY:
; 	Began 2007-04-23 15:06:10 by Marshall Perrin 
;-

pro himcut,oldim,oldhd, newim,newhd, imsize, xc,yc,$
	center=center,method2=method2

;-------- figure out center of subimage -----------

sz = size(oldim)
if n_elements(imsize) eq 0 then begin
    nx =  256
    ny =  256
    message, 'imsize not set, using default of 256', /info
endif else if n_elements(imsize) eq 1 then begin
    nx =  imsize
    ny =  imsize
endif else if n_elements(imsize) eq 2 then begin
    nx = imsize[0]
    ny = imsize[1]
endif else begin
    message, 'imsize must contain 1 or 2 elements!', /info
    stop
endelse
if keyword_set(center) then begin
    xc=center[0]
    yc=center[1]
endif
; center on peak pixel if desired
if keyword_set(peak) then  $
  whereismax, image, xc, yc, /silent


if n_elements(xc) eq 0 then begin
    message, 'x-position not set, choosing midpoint', /info
    xc = sz(1)/2
endif
if n_elements(yc) eq 0 then begin
    message, 'y-position not set, choosing midpoint', /info
    yc = sz(2)/2
endif

;-------- figure out corners of subimage -----------

dx = fix(nx/2)
dy = fix(ny/2) 
x0 = round(xc) - dx > 0
x1 = round(xc) + dx < (sz(1)-1)
y0 = round(yc) - dy > 0
y1 = round(yc) + dy < (sz(2)-1)
if not(odd(nx)) then x1 = x1-1
if not(odd(ny)) then y1 =  y1 -1
; revised 2006-04-28 by Marshall
; to better handle getting out odd arrays 
; centered on a half pixel
; TODO invoke automatically where appropriate?
if keyword_set(method2) then begin
	dx = (nx/2.)
	dy = (ny/2.)
	x0 = round(xc - dx) > 0 
	x1 = round(xc + dx-1) < (sz(1)-1)
	y0 = round(yc - dy) > 0 
	y1 = round(yc + dy-1) < (sz(2)-1)
	    ;stop
endif


if not(keyword_set(silent)) then $
    print, 'cutting = ', printcoo(x0, y0), ' to ', printcoo(x1, y1)


;-------- use HEXTRACT to do the real work -----------

hextract,oldim,oldhd,newim,newhd,x0,x1,y0,y1,silent=silent,errmsg=errmsg



end