;
; CALLING SEQUENCE:	scale=td_mk3scale(image)
;
; PARAMETERS:	image is the MK3 image to be sampled.
;
; NOTES:	This procedure is based on Alice's mkqual.auto.pro IDL 
;		procedure which scales MK3 images for the website.  This
;		procedure samples a ring of radius r0 to rmx and looks at
;		the min and max values found there.  Next some garbage is
;		taken out and the min and max scaling factors to use are
;		returned.
;
; RETURN TYPE:	FLTARR(2)
;
; CALLS:	None
;
; HISTORY:	Adapted from Alice's code on 2-JUN-98
;

FUNCTION td_mk3scale, image

nray=720
nraym1=nray-1

rpB=0
rpB=intarr(512,512)
rpB=image

acirc = !PI * 2.0 / float(nray)
dp    = findgen(nray) * acirc  +  acirc * (0.25 * (float(nray)))
dpx   = intarr(nray)
dpy   = intarr(nray)
xcen  = 255.5   & ycen = 255.5   &   mk3rad = 104.4435   &  radius=1.00
rnder = 0.5005
dpx   = fix ( cos(dp) * mk3rad * radius + xcen + rnder )  ; For disk size
dpy   = fix ( sin(dp) * mk3rad * radius + ycen + rnder )  ; For disk size

r0 = 1.25
dr = (255.5/104.44 - 1.1224) / 128.0
rmx= 2.00
rpix = fix((rmx-r0)/dr) + 1    &  rpixm1 = rpix-1

rimg = fltarr(rpix,nray)
fpix = float(nray)*float(rpix)

for ii=0,rpixm1,1 do begin;{
            RR=r0 + dr*float(ii)
            Rpx = fix ( cos(dp) * mk3rad * RR + xcen + rnder )
            Rpy = fix ( sin(dp) * mk3rad * RR + ycen + rnder )
            rimg(ii,0:nraym1)  = rpB(Rpx,Rpy)
        endfor ;}
        avg  = total(rimg) / fpix
        diff =  rimg - avg 
        sigma=  sqrt ( total(diff*diff)/fpix)
         
        mn = fix(fix(avg/ 50.)* 50.  - 2.5 *fix(sigma/ 50.)* 50.)
        mx = fix(fix(avg/100.)*100.  + 6 *fix(sigma/100.)*100.)
rimg= rimg*((rimg gt mn)  and  (rimg le mx))

       ; Recompute the avg and sigma
        avg  = total(rimg) / fpix
        diff =  rimg - avg 
        sigma=  sqrt ( total(diff*diff)/fpix)
         
        mn = fix(fix(avg/ 50.)* 50.  - 1.4*fix(sigma/ 50.)* 50.)
        mx = fix(fix(avg/100.)*100.  + 4.5*fix(sigma/100.)*100.)
        mn = fix(fix((avg - 1.3 *sigma)/ 50.)*  50.)  
                                                     ;;; if(mn gt 0)then mn=0
        mx = fix(fix((avg + 4.2 *sigma)/100.)* 100.)

scale=fltarr(2)
scale(0)=mn
scale(1)=mx
RETURN,scale
END