PRO spotchek,name,n1,overlap=overlap

edge=383
path='/jasper/cnsr3_data1/pgm/'+name
OPENR,big,path,/GET_LUN
im=ASSOC(big,BYTARR(383,383))
a=im(n1)
b=im(n1+1)
FREE_LUN,big
a99=pcentile(a,0.99)
b99=pcentile(b,0.99)
top=(a99+b99)/2.
a=a<top
b=b<top
cmp_flic,a,b,4,cs21,rs21,3,overlap=overlap
PRINT,'Images from '+path
PRINT,'To match image ',n1+1,' with image ',n1,',' $
     ,FORMAT='(A,I0,A,I0,A)'
PRINT,'shift upward ',rs21,' rows and right ',cs21,' columns.' $
     ,FORMAT='(A,I0,A,I0,A)'
RETURN
END