f: (8)
p AAp (9)
p! BAp
X7. Note that
ermined. The
formula (9) is
of the right
supposed to
i| to zero).
is equivalent
(10)
(11)
|] symmetric,
atrix B of
generalized
(12)
À1=0 of n-1
) À2 is given
(13)
3) 22=a'x, where x - eigenvector corresponding to Az.
From the statement follows, that the decision of
the problem (6) is under the formula
Ap - Br (14)
The effective algorithm of the numerical solution of the
problem — (14), based on triangular Cholecky
decomposition of B matrix was also offered in [1].
3. USING OF AN IMAGE SEGMENTATION IN THE
CORRESPONDENCE PROBLEM
Consider the more complicated a priori data: besides the
original images a result of segmentation of one of the
images (for example - left) is obtained. The segmentation
is a result of low-level or semantic analysis of the image.
Segmentation splits the image into not crossed regions.
The development of algorithms of segmentation is
beyond the scope of this work. Therefore it is considered
that the result of segmentation is given a priori.
y
* f g(xy)
xi x3
2 »
X
x wl
Left image Right image
Fig.1 a Designation of coordinates systems in the model
with preliminary segmentation
Let us designate s - segmentation of the template, which
represented by union of n not crossed regions %i
i=1,.,n:
zí]n9 ie
=| Jz (15)
The model used in case of three regions is schematically
shown on Fig.1. Taking into account the geometrical
distortions of images caused by a perspective projection
and the three-dimensional form of scene objects for each
region yi we consider its own affine distortion (16).
X; = A, +A,X + A3) (16)
y, ^ by t bx t by
The transformation (16) enters in each region y; a system
of coordinates (x;y), determined by a vector of
parameters pi = (@1i, A2, A3 bai, ba, bai). As in a case with
only one region (see Section 2), the initial approximation
of a vector of parameters (a*1,0,b*,0,1) and initial
distribution of intensity g*(x, y) are known.
4. LINEARIZATION STEP
Consider linearization of unknown function g(x,y) in
region xi with respect to g*(x,y) taking into account
parameters of transformation (16). In the differential form
expression (16) is
Ax, 2 Aa, + xAa,; + yAas
Ay, = Ab, + xAb,, + yAb,
(17)
Linearization of g(xi, yi) in region x; yields
gx, y,) = g' t g, Aa, * g,x Aa, + g, yAd,, * g, Ab, *
g,xAb, 3 g,yAb, = g, Ap
(18)
a =[o V0 8 g sg VB o£ ss O09
Ap" z [l Aa, Ad,, Ad, Ah, Ab, Abo) .
1 Aag,, Aa, Aa, Ab, Ab, 5j.
1 Aa,, Aa,, Aaj, Ab, Ab,, Ab, , ]
The vector gi of dimension 7n has the following structure:
first 7(i-1) of components are equal to zero, 7 coefficients
of linearization further follow, last 7(n-i) of components
are also equal to zero. The vector Ap of dimension 7n is
assembled from transformation parameter amendments
of all areas.
5. TRANSFORMATION OF A CROSS-CORRELATION
COEFFICIENT
In view of the entered splitting on regions (3) can be
transformed as follows
197