International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV ‚ Part B-YF. Istanbul 2004
patches and improved its quality by several pre-processing steps
to be used by TM algorithm (Fig.3).
Resampling the Template
Y |
Localization |
Y ; :
Figure 3: Desired mask
Precise measurement
.FA-
o be 3.3 Image pyramid derivation
es of v
Is to Transformation parameters On different pyramid levels we use different representations for
eces the fiducials. On highest levels we use the whole fiducial mark
>s in including its surrounding(Fig.4 left) On the lower levels the
tting
fiducial figure (Fig.4 Right), and only on the lowest level where
mal, Figure 1: The whole procedure of AIO final measurement is done, the same which was used for
previous step is used (Fig. 4 Right).
e by
ct to 3.1 Extracting image patches
both
nple To do the job, one doesn't need to use the whole image so we
ss of just extract the patch including fiducial mark and its
t the surrounding (Fig.2). This helps us to reduce the amount of
information and to increase the speed of computation. The size
of patch is dynamically changing in correlation to the image
size.
ween
inner
letric
igital
al of
le to Figure 4. Left: Pattern of fiducial mark and its surrounding.
ation Right: Pattern of the fiducial mark figure.
.FA- :
dure 3.4 Detection of the orientation of the image
isted
In KFA-1000 photos, four of the fiducials are normally located
in the center of each side of the photos and the fifth one is
located in photo center as shown in Fig. 5. We employed two
techniques of TM (Template Matching ) with combination with
calculating moments parameters which are independent of
image rotation to determine the tolerance rotation of (-3,3).
in be 2
ming
ecise
only. Figure 2: Extracted image patch
1 5 3
3.2 Resampling the template
How to resample the template affects the success and accuracy
of TM (Template Matching) and output data as more we
improve the quality of template more accurate output data and 4
0) is Template Matching algorithm will be. Here, since we knew the
kind of camera so we resampled the template from the extracted
Figure 5. Fiducial distribution on a KFA-1000 photo
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