Russian 

Fig.9 
To avoid superfluous losses
of time, the operation of rough choice of the contour points concerning
to the flowing contiguous segment was applied. In the beginning for an evaluation
of coincidence measure gradient of chosen contour points (the list of references
to their initial set is formed) which lay inside a wide rectangle enclosing
the contiguous segment in its flowing position (such neighbourhood is
shown by fat primes on fig.12).
Fig.12 
Operations
of deletion and preliminary choice have not only engineering sense.
A solution of basic problems depends on their organization too. In particular,
ability of the procedure to understand complicated situations depends on
their organization,  at processing of false concentrations of contour
points, in the case of capture of several segments. In similar cases
the number of steps noticeably increased (sometimes so, that it was necessary
to discontinue compulsorily process of searching). Detection of such situations
was carried out by criterion of filling ratio of resulting segments by
contour points. An example of such situation is shown on fig.11. On this
picture it is shown the initial (dotted line) and finite (solid line) positions
of the contiguous segment, corresponding to process of search of one local
maximum. Apparently, the right branch of the initial contiguous segment
has not had time to be rounded along the corresponding piece of
the contour line and intersected an adjacent contour.

Fig.11 
This example
illustrates common logic of solution of complicated situations.
To solve them it is necessary to begin from the outside  from the
"free" ends of entering lines.