Assuming the probability of the object
omission is Pr» , it is possible to dof
no the dimensions of fi =R t - image frag
ment which includes ith object with
1-V* probabil jty
Then for the ith object segmentation it
is sufficient to process not the full
image but its fragment bounded by a side
2R; with a centre in the point (x;,y ; ),
For k-objects segmentation the number of
such fragments is equal! to k. If ith
fragment doesn’t have intersections with
any other fragment then within this fra
gment, there are only a background and
the ith object. Since the fragment di
mensions are smail then it can be consi
dered that the background velocity in
all pixels of a single fragment is con
stant. Then the segmentation procedure
can be realized not by the sliding win
dow but with taking into account all
fragment pixels, which increases velo
city calculation accuracy, procedure
convergence and reduces the computeti-
onal burden.
The algorithm allows the general Lzation
for the object arbitrary motion case. In
this case the echo frequency on an ob
ject image element corresponding to the
ith region of an image is defined as
follows
as)
where g t - is a projection of an object
translatory motion on to the line of
sight; are angular rates of an
object rotation relative to !,he ortho
gonal axes lying in the plane perpendi
cular to the line of sight; q is a pro
portionality factor. Then in accordance
with the adopted model we get that the
vector of the observed Doppler frequen
cies values of the ith region b\ can be
presented in the form
07)
where TjsdjjXjY) is the transformation
matrix of dimensions n* 3; G,- = (g; ) T
is the ith region velicity vector; 6i
is the measurement errors vector; nj is
the number of pixels in ith region.
To define the most likely vector esti
mation It,’s necessary to solve vector-
matrix equation (17) is relation to Gi
for the given vector of observable fre
quencies Fi . In the general case the
solution of this equation can be obtai
ned using pseudoinverse matrix method
(Albert,1972 ). However, for the segmen
tation of separate image fragments
containing isolated objects the more
simple result for Gi vector estimation
may be obtained, using method of least
square. In this case we realize the ne
cessity of recursive solution of the
following system of the thrird-order
linear equation with respect to vector
components g ; , ox , £ c
The summation is carried out for all
pixels of ith fragment having a state
s=1. The system (18) is resolved accor
ding to the Kramer's rule find is written
in the form
where^ and Aj are corresponding system
determinants.
In realizing the segmentation pricedure
the system (18) must be resolved every
time as soon as any pixel of analysed
fragment changes,
8. THE ii/iATHEMATTO MODELING OF THE
SEGMENTATION ALGORITHM AND CONCLUSIONS
The jriathematic modeling has shown that
as a rule the algorithm converges in 5-
10 iterations and the algorithm with
a priori given coordinates of regions
converges in 3-8 iterations. The initial
segmentstion qua!ity doesn't practically
affect the processing results and does
affect only the number of iterations.
In modeling of algorithm implementation
for a plane-parallel objects motion an
acceptable result was obtained using a
window of 3x3 pixels size. But the esti
mation of the velocity vector G for ob
jects arbitrary motion such dimensions
provide unsatisfactory results. The sa
tisfactory quality of the segmentation
was obtained when the frequency was es
timated with a window of 9x l 3 pixels
size and the pixels connection was based
on the analysis of the window of 3x3
pixels size. Even better result was ob
tained in modeling the segmentation al
gorithm with a priori given coordinates
of regions.
When implementing the segmentation algo
rithm for arbitrary moving objects using
a mainframe digital computer the total
number of computer operations for pictu
ring of 912x128 pixels will amount to
10-12 million for one iteration. Using
a fragment of 40x10 pixels size this va
lue will be about 200 thousand operati
ons for one iteration.
Fig.1-10 illustrate the segmentation of
the proposed algorithm. Elf.1 shous the
reference image for DOT computer genera
l-ion in case of plane-parallel objects
motion. Moving objects have the forms of
simple geometric figures. Fig.2 presents
720