[Studies in Computational Intelligence 481] Artur Babiarz, Robert Bieda, Karol Jędrasiak, Aleksander Nawrat (auth.), Aleksander Nawrat, Zygmunt Kuś (eds.) - Vision Based Systemsfor UAV Applications (2013, Sprin

22 A. Babiarz et al.
particular angle changes. Moreover, particular “speed” values from the [-5, -4, …
,+5] range are the total multiplicity of the smallest “speed”. This analysis allowed
to define the dependence between the increment value defining the rotation of a
given axis and the value of the particular angle expressed in degrees. Respectively,
in the analyzed camera model, for the Pan and Tilt parameters, the dependencies
are described with the formulas:
15
679 (1)
15
262 (2)
where , are respectively the increment values in the configuration connected
with the rotation of the camera head around the axes to Pan and Tilt.
In the case of the third parameter (Zoom) defining such a simple model was not
possible. During the analyzed experiments, the changes dependence of the optical
object magnification in the function of values of corresponding increments proved to
be ambiguous, dependent on the direction (the growth or reduction of the
magnification value factor) to which the Zoom parameter value was being changed.
The route of the characteristic determined by the Reading of the increment values
and the OSD module displaying the image about the magnification of the image
from the camera was show on a logarithmic scale on fig.15.
magnification factor value
10
1
4000 4200 4400 4600 4800 5000 5200
incerment value
Zoom Up Zoom Down Mean Zoom
Fig. 15. The characteristic of the change dependencies of the magnification factor
depending on the increment values
The characteristic shown onfig.15 was defined on the semi-logarithmic plane.
For such representation, the averaged dependency (Mean Zoom) appears to be
approximately linear. This suggests a model class, among which one should
search for analytic dependencies defining the relationship between the Zoom value
and increment value. The first, tested class are the exponential form models: