1SPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS", Bangkok, May 23-25, 2001
246
The recognition result was provided very accurately because the
gray-level image processing is simple and fast to calculate the
template matching. Moreover the sign images do not have the
pattern variation. However, still, this step is not a real-time
processing depending on the hardware.
Example of Sign Positioning by a new algorithm
The result was calculated (see table 2) and compared the
accuracy with the conventional method (see the figure 9).
Table 2 each sign position by the indirect measurement
Northing(Meter)
Easting(Meter)
Sign No.l
1554294.8
647194.1
Sign No.2
1554266.4
647046.8
Sign No.3
1554272.9
646760.6
Sign No.4
1554289.3
646318.5
Sign No.5
1554231.7
646156
Sign No.6
1554136.7
646136.8
Figure 11 the accuracy of the new method compared with conventional method
The accuracy of the new method compared with
conventional method
After sensor was calibrated, the sign position was repeated and
recalculated with the new algorithm. The best result is a one-
meter difference of the position in the Sign No.3 compared with
the high-accurate sign position from the RTK-GPS conventional
method.
5 Conclusion
This research is the beginning of the Thai Road Sign Recognition
and Location. The algorithm has been developed simply but the
accurate result was obtained specially for the Road Sign
Recognition. However there are still limitations to study for the
real application. Therefore the further study should considered
with the Single GPS and a variety of study area.
Acknowledgement
Specially thank you for Space Technology Application and
Research Program, Asian Institute of Technology to give me very
skilledful education. Thank you for Asian Center of Remote
Sensing Research to support the RTK-GPS sensor.
6 Reference
Chen X., Murai S., 1998, Automated Mapping: An Introduction of
Map Image Interpretation, Asian Institute of Technology, 87-91
Dana, P. H, 1997, Global Positioning System Overview, web site
http://utxass.edu/depts/qrg/gcraft/notes/gps/gps/gps.html,
Department of Geography, University of Taxes at Austin.
DGPS InQuest: Demonstration Software for GPS,
URL:http://www.quailtveng.co.uk/dqps/dqps1.html
Dinesh, M, 1998, Procedural Development for Level Surveying
Using Real Time Kinematic GPS, M.Eng. Thesis, School of
Environment, Resources and Development, The Asian Institute
of Technology, Bangkok, Thailand
Geomatics Canada, Geodetic Surveying division, Accuracy
Standards for Positioning
Donald H., M.Paluline Baker, 1994, Computer Graphic:Affine
Transformation,208
