pro fov,fname,fbias
if ( n_params(dummy) eq 2 ) then begin 
   reads,fbias,b,nx,ny,0
   reads,fname,p5,nx,ny,0
   p5=p5-b
   reads,fbias,b,nx,ny,1
   reads,fname,p6,nx,ny,1
   p6=p6-b
   reads,fbias,b,nx,ny,2
   reads,fname,p7,nx,ny,2
   p7=p7-b
   reads,fbias,b,nx,ny,3
   reads,fname,p8,nx,ny,3
   p8=p8-b
   b=0.
endif else begin
   reads,fname,p5,nx,ny,0
   reads,fname,p6,nx,ny,1
   reads,fname,p7,nx,ny,2
   reads,fname,p8,nx,ny,3
endelse
print,'compressing'
p5=congrid(p5,400,400)
p6=congrid(p6,400,400)
p7=congrid(p7,400,400)
p8=congrid(p8,400,400)
;
print,'median filtering p5 ...'
p5=p5-median(p5)
print,'median filtering p6 ...'
p6=p6-median(p6)
print,'median filtering p7 ...'
p7=p7-median(p7)
print,'median filtering p8 ...'
p8=p8-median(p8)
;
in=18
tvwindow,0,xsize=800-2*in,ysize=800-2*in
tv,       3*p5(in:*,in:*)+40   ,400-in,400-in
tv,rotate(3*p6(in:*,in:*)+40,1),0     ,400-in
tv,rotate(3*p7(in:*,in:*)+40,2),0     ,0
tv,rotate(3*p8(in:*,in:*)+40,3),400-in,0
stop
end