PRO Image_Diff, infile=infile IF keyword_set(infile) then begin im=readfits( infile ,h) endif else begin print, 'Input File Needed' endelse n=sxpar(h, 'NAXIS3') diff=make_array(4096,4096,n-1) for n=0, n-2 Do Begin diff(*,*,n)=im(*,*,n+1)-im(*,*,n) endfor plot, diff(1000,1000,*) print, diff(1000,1000,*) print, stddev(diff(1000,1000,*)) print, avg(diff(1000,1000,*)) stop end