; the
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itive
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ction
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ation
rmed
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13)
14)
15)
jt in
olour
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through the first order condition for stationary points of (16).
The stationary points of (11) can be found by means of
Lagrange multipliers, which is given by
BE CN. BA C
$E Y Gyr e s anm
i=l k=1 k=1 izl
Setting the gradients of J, with respect toy , y and 4 equal to
0, when p? »0 and; »1,theU , V would minimize only if
nee IxisC,IskSsN.(9)
j=l D,
And
Sx, 1<i<C(20)
2
i
up N
s Qu)"
FA
Thus, we could simply apply the fuzzy C-means algorithm, by
performing the iteration of (19) and (20).
4. CLASSIFICATION
Two different approaches were taken to perform the
classification ~~ process, supervised and unsupervised
classification.
4.1 Supervised classification
In the study area, the data has 538299 points and has a density
of 1.2points/m?. Five typical types of objects, bare land, trees,
houses, road and farm land, were selected and formed the
training data and their properties were computed.
Figure 1: supervised point cloud classification result
The classification result is presented as in figure 1. The results
shows that by the addition properties, that are the width,
amplitude and cross-section of the backscattered waveform,
objects of the same height but has different width and cross-
section could easily distinguished. Also, object in
neighbourhood spaces could also be separated by components’
intensity and width parameters and research an excellent
classification performance. However, because of the correlation
among the parameters, which draws back the classification
results.
4.2 Unsupervised classification
Figure 2. Unsupervised classification results
The correlation among the parameters was removed by the
transform and the parameters were applied to the point cloud
classification using Fuzzy C-Means algorithm. The
classification result is shown in figure 2, which shows that low
vegetation point could be classified and improve the
classification performance.
5. CONCLUSION
The experiments in this paper shows that by using the additional
parameters abstracted from full-waveform LiDAR, supervised
classification approach could research good classification
performance. Also, through IHSL transformation of the
parameters, then the fuzzy C-means algorithm is applied to the
derived new space to complete the LiDAR point classification
procedure. By comparing the two different segmentation results,
which may of substantial importance for further targets
detection and identification, a brief discussion and conclusion
were brought out for further research and study.
6. REFERENCES
A. Charaniya, R. Manduchi, and S. Lodha, "Supervised
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C. Frueh, S. Jain, and A. Zakhor, “Data Processing Algorithms
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C. Mallet and F. Bretar, “Full-waveform topographic lidar:
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