ISPRS Commission III, Vol.34, Part 3A Photogrammetric Computer Vision“, Graz, 2002 
Then the angle o5 ;;i-th record about which it 
is needed to rotate the record to validate 
1 1 D: 
T, =T,, T, =T, is determined; and translate the 
records that T! = T . Finally the general equations of 
R and S-lines are determined and the pixels color in 
resulting image is calculated. 
The computation of pixel intensity 
Determination of general equations of X and Y-lines 
I label the new x and y-coordinates of 
detection objects centers T/, T, by the symbols 
T! (x), T! (y), T^ (x), T: (y). With known positions of 
every record detection objects centers it is possible to 
determine the position of its X and Y-lines for each 
record. 
As it was mentioned before in the first step of 
the enhancement the new image with double 
resolution is created using the first record pixels. Then 
the line given by detection objects centers T; , T; in 
the. ith record will, have the slope 
k = (ri(y) - T4y))/ (T: (x)-T, (x)) according to 
the selected coordinate system. Then for angle 6; 
which includes this line with positive direction of x- 
axis is valid ó;;-arctan(k;). 
Let & := à, be angle which includes the line 
given by centers of detection objects in the first record 
with the positive directions of x-axis. Because the 
resulting image basis was created by resampling of the 
first record, R and S-liens in the first record have 
consistent direction with R and S-line of the resulting 
image. For angle which include R-lines of the record 
with positive direction of x-axis in the i-th record is 
valid o; := 0; - 5. The same size has the angle which 
include the S-lines with positive direction of y-axis 
because R and S-lines are perpendicular to each other. 
Also it is valid that o ^ 0; - 6 = 5,- 6, =0. 
The o; angles of R and S-lines are known. To 
find their general equations for ever R and S-line one 
its point is selected. Let be the selected point from R 
line or S line respectively. 
In this method the R-line points are 
calculated in the way that x-coordinate is determined 
and y-coordinate is calculated. For S-lines it is 
reversaly. The procedure is as follows: 
The records are translated in a way that the 
i : 1 . 
centers T! coordinates are equal to T, coordinates 
in integer parts. Then for coordinates By; , and Bx 
of R and S-lines in the i-th record is valid 
Bx! Ve a = (Y. +17) +G-i)*s; (8 
By; 2G, o Yu) Xy = (X *1-T6G-0*s, (9) 
where 
Xn» Y= ale coordinates of the first center in the 
1 1 
first record 
  
  
  
r" r^ 
]! 1° = , where (10) 
COS Q5; COS U; 
y X 
T ya) Var T e om 
while ( ) is the label of integer part 
S; = , Where (11) 
COS QI; 
t is the size of record pixel side 
j - order number of R resp. S-line, j — 0, ..., number of 
R resp. S-lines 
The calculation of y-coordinatesof R-lines is 
illustrated in FigureX. 
ü 
  
  
  
  
  
  
Figure 6 The calculation of y-coordinates of R-lines 
of the record 
Because the angles 0; and points Bx! ; By: 
of R and S-lines of the record are known it is possible 
to express their general equations 
For R-lines: 
(go, *x-y-tao, *x y 70 (12) 
1 X] 
for S-lines: 
Xen Ey (13) 
X] 1 
Now it is possible to determine the intersection of 
these lines. 
The calculation of R and S-lines of the records and 
resulting image 
R and S-lines in resulting image are parallel 
to coresponding coordinates axis. Now their 
intersections with R and S-lines of the records are 
determined. 
When y resp. x-coordinates are set into 
equations of R resp. S-lines of the records the 
intersections can be calculated using the system of R 
and S-lines general equations. Finally the intersections 
of R and S-lines in the resulting image are computed. 
Because these lines are parallel to choosed coordinate 
system axis their intersections have the coordinate 
values equal to values in general equations of these 
lines. 
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