24 
  
    
     
sensor receives the lu 
512x512 minous fiux transmitt- 
L——— Sema [3] ed py the*'strip' of the 
im sein photogram actually il- 
H.r.cli 
  
| MFA FS ael ; à 
| | ste © luminated by the lamp, 
SO“ that one row Of the 
| MFA LS e image is digitized; the 
  
  
  
     
    
  
whole image is scanned 
  
  
  
   
  
  
  
  
  
  
  
  
  
  
  
  
  
   
  
    
  
    
COMMON : 
| Mns rh row by row, according 
PRINTER Ls] STORAGE | to the shifting of the 
Hs ; 
| aeris. T plate holder along X di 
! PAPE Ig rection produced by the 
| S TEL E A E motorized assembly. 
| "PRINTER TS 0 Mb rn 
LE CN | The spatial scanning 
a L- frequencies are deter- 
MIERMINAL | | x 
s > | mined'by the sensor geo 
hut Neb. IA x metry, the objective 
MS m- DS | | charecteristics and the 
So bin 
/ fa Step advance of the as- 
oncept ue | sembly. The sensor con- 
| 32/27 f: y | 24 de 
VPS MAP 300 paie CIE da | tains active elements 
Red = ii | 2^Mb à 61 | fI ~ 2 : à 1 
| eus | Of 15x Sum wich. 13. um 
J y | 2 
1024x1024\ | spacing:. thus a 15 .um 
DISPLAY i : : 
CON OTUR sampling interval along 
  
  
  
X-direction in the sen- 
SOr plane is obtained, 
and, due tO the magnifi 
cation M=0,15 introduc- 
ed" py) the optics, an' et 
fective sampling inter- 
val p,=100 um is obtained in the film plane. Because the linear 
step of the motorized slider is 100 um, the image is scanned 
with equal frequencies both in X and Y directions. 
Fig.4: The Processing Structure 
MFA-250-LsS main features are listed in Tab.1; the device is 
shown in fig.96. 
6. The Procedures 
Among the PO to P5 procedures above mentioned, we will describe 
only P4 and P5 procedures, which are of particular interest for 
our purposes. (4) 
6.1 Thresholding Procedure 
As already mentioned, the graphic image of the reticle, made i 
deally up of a homogeneous background and o 
curves, after the acquisition process 
ge whose pixels have photometric valu 
tinuous scale and whose ge cric. iin 
a set of simple 
" 
ometric