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GRASSを用いたオブジェクトベース分類

2017/05/16 Seiya Ishibashi (一部修正)

Object based classification

What is segmentation?

Segmentation is process which make segment based on the spectrum and geographical info.

Segmentation in QGIS.(OTB)

here

Segmentation in GRASS.

g.region rast=2016_1207_backscatter_latlon.1

i.group group=test_group input=2016_1207_backscatter_latlon.1

# below command is segmentation process.
# If you set threshold at lower value, then segmentation is more in detail (and takes much time).
i.segment group=ortho_group output=test1_seg threshold=0.02 # Since threshold is lower value, running takes over 30 minutes.
# Then, you need to adjust the threshold value by checking the created map. 
i.segment group=ortho_group output=test1_seg threshold=0.1 # takes around an hour.

i.segment group=ortho_group output=test1_seg threshold=0.2 # takes over 30 minutes.

i.segment group=ortho_group output=test1_seg threshold=0.3 # takes over 30 minutes. 







Last modified:2020/03/14 17:58:07
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