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2. Wall Boundary Extraction Results ( for Liaoshang Jing ). Wall Extraction. In order to understand wall condition about physical change, we tried to extract wall boundaries using satellite data.
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Wall Extraction • In order to understand wall condition about physical change, we tried to extract wall boundaries using satellite data. • Both typical edge detector, Laplacian, and Mathematical Morphological Operator, ATM (Alpha Trimmed Multidimensional morphological detector), were applied to low resolution satellite data.
Example of Satellite ImageADEOS/AVNIR Multi image Liaoshang Jing Path=1190,Row=440 Date : 1997.04.11
Example of Satellite ImageADEOS/AVNIR Panchromatic image Liaoshang Jing Path=1190,Row=440 Date : 1996.12.19
(c) AVM Band3 (a) AVM Band1 (b) AVM Band2 (d) AVM Band4 (e) AVP (f) OVN Band1 (i) SAR (g) OVN Band2 (h) OVN Band3 Satellite images around Liaoshang Jing
Laplacian and ATM Laplacian operator where f(x,y) and foutput(x,y) are the input image and the output image respectively ATM operator where fdil(x,y), fclo(x,y), fope(x,y) and fero(x,y) are the morphological dilation, closing, opening and erosion processed images respectively.
Comparison of the resultsfor ADEOS/AVNIR Panchromatic Data Laplacian is applied ATM is applied White pixels :detected wall boundaries (after thresholding)
18 16 Lap b/a 14 12 Lap b/c 10 (%) ATM b/a 8 6 ATM b/c 4 2 0 AVM AVM AVM AVM AVP OVN OVN OVN SAR 1 2 3 4 P 1 2 3 L Accuracy of wall extraction Sensor Band a: actual wall boundary pixels b: logical add of a and cc: detected wall boundary pixelsLap:case of Laplacian applied ATM:case of ATM applied ATM analysis using AVP is most effective.
But… • The accuracy, however, are not practically admitted. • High resolution satellite images such as IKONOS or Quickbird are necessary to improve the accuracy.