153
RESEARCH OF DETECTION AND TRACING ALGORITHM OF
EXTENDED OBJECTS ON RADAR SCENES1
D.G. Khafizov2, I.G. Yakovlev2
2Mari
State Technical University, the Regional Reseach Laboratory of Group Point Objects
and Point Scenes Image Prosessing, Lenin Sq. 3, 424000 Yoshkar-Ola, Russian Federation.
tel.:(8362) 455412. e-mail: rts@marstu.mari.ru
The optimum strobe sizes for tracking the extended objects on radar scenes are defined,
the probability characteristics of correct detection and an estimation of extended object
parameters are obtained.
Introduction
Detection, estimation of parameters, tracking
and recognition of communication objects of
the extended filiform structure, are one of the
major purposes of radar images processing.
Such objects are roads, rivers, bridges (Fig. 1),
etc.
tracking and estimation of extended objects
parameters proved that when analyzing their
efficiency the primary purpose was to obtain
their detection characteristics.
However there are almost no studies of methods and algorithms dealing with the estimation
of determination accuracy parameters of extended objects (length, width and angle), obtained by the results of their tracking.
CatEye algorithm
Fig. 1. Example of the image with extended filiform
objects
Characteristic features of such objects are long
extension narrowness. The methods of extended objects detection and tracking problems solution are considered in [1-3]. On the basis of
these methods the algorithm of program CatEye was developed which allows to find out,
track and define the parameters of extended
objects. The review of methods of detection,
CatEye program algorithm consists of two
basic stages of processing: objects detection
and tracking the extended object. After object
detection the accumulation of image brightness takes place at different angles (for objects
with different inclination angle) and definition
of gaps in the accumulated brightness line,
corresponding to the object parameters. Further by the object points defined tracking and
coding of the extended object is carried out.
Tracking is carried out on the basis of tcriterion with the use of a round strobe consisting of the lateral zone representing the background and the central zone representing the
object.
Thus the results of tracking to a considerable
degree depend on the parameters of algorithm
setting, such as the size of strobe to be tracked,
the number of accumulated lines of the image,
etc. Therefore before carrying out the research
of noise action with the purpose of estimation
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1
Work is executed under the financial support RFFI, project 07-01-00058а
154
of tracked objects parameters the optimum
strobe dimensions providing the best definition
of extended filiform objects parameters without noise were defined.
Further research of algorithm was conducted
on the basis of generated test images-phantoms
with the set parameters of brightness noise,
width, length and an inclination angle of extended object.
Research results
As a result of the research conducted the following characteristics were obtained.
1. Dependence of correct detection on standard deviation (SD) of brightness noise for
extended objects with various width (Fig.
2).
2. Dependence of inclination angle  definition errors on SD of noise for objects with
various width (Fig. 3).
3. Dependence of object length definition error on SD of brightness noise for objects
with various width (Fig. 4).
Width=1
P
1,05
Width=2
Width=3
1
0,95
0,9
0,85
SD
0,8
0
20
40
60
80
100
The obtained characteristics allow to estimate
the algorithm accuracy of program CatEye, to
define the most reasonable parameters of algorithm work from the point of view of processing accuracy and on their basis to develop
more effective methods of detection, tracking
and an estimation of extended filiform objects
parameters.
ΔL
18
16
14
12
10
8
6
4
2
0
0
Width=1
Width=2
Width=3
20
40
60
80
SD
Fig . 4. Characteristics of object length error definition
on the SD brightness noise for the objects with various
width
Conclusion
Errors of parameters definition are caused by
imperfection of algorithms, presence of noise
in the scene, image sampling errors, etc.
The importance of this work is that the characteristics of definition accuracy estimate parameters of extended objects (width, length
and inclination angle) were obtained for the
first time by the results of their detection and
tracking on algorithm of program CatEye.
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References
Fig. 2. Characteristics of extended objects correct detection on SD of the brightness noise for objects with various widths
Width=1
Width=2

2
1,8
1,6
1,4
1,2
1
0,8
0,6
0,4
0,2
0
Width=3
SD
0
20
40
60
80
100
Fig. 3. Characteristics of dependence of inclination angle definition errors on SD of noise for objects with
various widths
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