pro fits_up_the_ramp, fitsfilename=fitsfilename

If not(keyword_set(fitsfilename)) then fitsfilename = $
'/Volumes/Seagate2/07Apr24/NGC_6791_Dither6_20ArcSecondsWest_0ArcSecondsNorth_H4RG_SIPIN_4_Reads_Apr25_2007_04_49_59.fits'

fits_read, FitsFileName, Im, FitsHeader, /header_only

Naxis1     = double(sxpar(FitsHeader,'NAXIS1'))        
Naxis2     = double(sxpar(FitsHeader,'NAXIS2'))         
TotalReads = sxpar(FitsHeader,'NAXIS3')                      
NumGroups = sxpar(FitsHeader, 'NGROUPS')
NumReads = sxpar(FitsHeader, 'NREADS')
ArrSize = double(Naxis1*Naxis2)
DifferenceImage = UIntArr(Naxis1, Naxis2)

for PixNum = long(0), long(ArrSize) - 1. do begin
  TempPixNum = PixNum
  fits_read_depth, FitsFileName, depth = 1, PixelNo = TempPixNum ,data
  GroupPix = UIntArr(NumGroups)
 
  for GroupNum = 0 , NumGroups -1 do begin
      DiffPix = UIntArr(NumGroups)
      DiffPix = Mean(Data(NumReads*GroupNum+1:NumReads*(GroupNum+1) - 1) -$
		Data(NumReads*GroupNum  :NumReads*(GroupNum+1) - 2))
      GroupPix(GroupNum)= DiffPix
      
  endfor
  DifferenceImage(PixNum mod UInt(Naxis1) , long(PixNum) / UInt(Naxis2)) = Mean(GroupPix) 
  print,pixnum

endfor

stop

end