pro boxp4,x1,x2,y1,y2,scam

;Extracts subimages of pore P4 to be used in sonic filter,
; movies etc.
;x1,y1 = lower left corner coordinates of the selected box.
;x2,y2 = lower left corner coordinates of the selected box.
;scam  = string 'a' or 'b' to select the camera
 
;----------------------------------------------------------

;parametros de entrada a modificar con editor

init=1		;first frame
numim=220	;number of frames

n=1280       	;dimension en x
m=1032       	;dimension en y

st1a=string(scam+'_ser23/'+scam+'_ser23.')	;input
st1b=string(scam+'_ser23/p4.')			;output

;---------------------------------------------------------

im1=intarr(n,m)

FOR i = 0,numim-1 DO BEGIN

   dcn=strtrim(i+init,2)
   print,'Copying/extracting image  ',st1a+dcn,'  to  ',st1b+dcn

   openr,1,st1a+dcn
   readu,1,im1
   close,1

   bb=im1(x1:x2,y1:y2)

   openw,1,st1b+dcn
   writeu,1,bb
   close,1

ENDFOR

end