pro newcentroid, array, c, r, ccntr, rcntr

; WARNING: This procedure may return a centroid location outside the bounds
; of the array.

; Find second brightest pixel among pixels surrounding array(c,r)
d = fltarr(3,3)
for di = 0,2 do begin
  for dj = 0,2 do begin
    d(di,dj) = 1000000.
  endfor
endfor
s = size(array)
i1 = c-1
if (c eq 0) then i1 = c
i2 = c+1
if (c eq s(1)-1) then i2 = c
j1 = r-1
if (r eq 0) then j1 = r
j2 = r+1
if (r eq s(2)-1) then j2 = r
di = 0
for i = i1, i2 do begin
  dj = 0
  for j = j1, j2 do begin
    d(di,dj) = array(c,r) - array(i,j)
    dj = dj +1
  endfor
  di = di + 1
endfor
for di = 0,1 do begin
  for dj = 0,1 do begin
   if (d(di,dj) eq 0) then d(di,dj) = 1000000.
  endfor
endfor
dmax = min(d,dindx)
if (c eq 0) then cindx = c + (dindx mod 3) else cindx = c + (dindx mod 3) -1
if (r eq 0) then rindx = r + (dindx / 3) else rindx = r + (dindx / 3) -1

; Find the coordinates (ccntr,rcntr) of the maximum point of the parabola
; passing through the brightest and second brightest pixels, and two pixels on
; either side.

case (c-cindx) of
-1: begin
  xx = [-1, 0, 1, 2]
  case (r-rindx) of
  -1: if (r eq 0) or (c eq 0) then begin
        xx = [0, 1, 2]
        find_max, 3, 0, array, c, r, xx, sqrt(2.0), ccntr, rcntr
      endif else begin
        find_max, 4, 0, array, c, r, xx, sqrt(2.0), ccntr, rcntr
      endelse
   0: if (c eq 0) then begin
        xx = [0, 1, 2]
        find_max, 3, 2, array, c, r, xx, 1, ccntr, rcntr
      endif else begin
        find_max, 4, 2, array, c, r, xx, 1, ccntr, rcntr
      endelse
   1: if (r eq s(2)-1) or (c eq 0) then begin
        xx = [0, 1, 2]
        find_max, 3, 1, array, c, r, xx, sqrt(2.0), ccntr, rcntr
      endif else begin
        find_max, 4, 1, array, c, r, xx, sqrt(2.0), ccntr, rcntr
      endelse
   endcase
  end  ; (c-cindx) = -1
 0: begin
  case (r-rindx) of
  -1: if (r eq 0) then begin
          xx = [0, 1, 2]
          find_max, 3, 3, array, c, r, xx, 1, ccntr, rcntr
        endif else begin
          xx = [-1, 0, 1, 2]
          find_max, 4, 3, array, c, r, xx, 1, ccntr, rcntr
      endelse
   0: begin
        print, ' Error - the second brightest pixel cannot be the same as the brightest pixel'
        stop
      end
   1: if (r eq s(2)-1) then begin
          xx = [-2, -1, 0]
          find_max, 3, 3, array, c, r, xx, 1, ccntr, rcntr
        endif else begin
          xx = [-2, -1, 0, 1]
          find_max, 4, 3, array, c, r, xx, 1, ccntr, rcntr
      endelse
    endcase
  end  ; (c-cindx) = 0
 1: begin
  xx = [-2, -1, 0, 1]
  case (r-rindx) of
  -1: if (r eq 0) or (c eq s(1)-1) then begin
        xx = [-2, -1, 0]
        find_max, 3, 1, array, c, r, xx, sqrt(2.0), ccntr, rcntr
      endif else begin
        find_max, 4, 1, array, c, r, xx, sqrt(2.0), ccntr, rcntr
      endelse
   0: if (c eq s(1)-1) then begin
        xx = [-2, -1, 0]
        find_max, 3, 2, array, c, r, xx, 1, ccntr, rcntr
      endif else begin
        find_max, 4, 2, array, c, r, xx, 1, ccntr, rcntr
      endelse
   1: if (r eq s(2)-1) or (c eq s(1)-1) then begin
        xx = [-2, -1, 0]
        find_max, 3, 0, array, c, r, xx, sqrt(2.0), ccntr, rcntr
      endif else begin
        find_max, 4, 0, array, c, r, xx, sqrt(2.0), ccntr, rcntr
      endelse
   endcase
  end  ; (c-cindx) = 1
endcase

stop
return
end