30 
  
data input: 
photogram 
| 
V 
digitization of the photogram 
and set up of matrix A(i,j) 
  
  
  
  
V 
thresholding of matrix A(i,j) 
and set up of matrix A'(i,j) 
  
  
  
Vv 
thinning of the lines of the 
raster and set up of matrix A" (3 i) 
| 
Research of the coordinates of | 
the node points of the raster 4 
subsequent storage on magnetic tape | 
| 
v 
| STOP | 
Figure 1 
  
  
  
  
  
and 
  
2 * 
z2535292232525259532 = 
LLLILIIIITI 
225936222282 
22282525223223232353422525325323532232 
$25s2232u52323223285223323 
22s25252552528382355435235225522 
3222222222222020200200000002004 Table 1 
383223333883 3333388833333383883 
= 99222525225822525222422353225: 
25s595222235222353282 
= 
282833332383 
3833835333888 
asas 
Digitized Image 
  
The measurement of the coordin 
Coordinate system is facilitat 
matrix itself. 
the matrix 
ates of the nodes in 
ed by a pre-processing of the