be considered as
losing operations
1 each image was
hological Profile
|(x) serious with
| pixel value was
(5)
oz S f(x) £7,
e between 140 to
uilding roof must
lue 1.
x by a composite
? set of points, x,
with x, Np fits
LOY (9
d (7,17), of
lements sets for
sists of 7,11,15
(b)
Ishinomaki area
d for a series of
e airborne images
| Tsunami site of
yan were used for
and ENVI 48
image processing
; the RGB color
City area Miyagi
ınami event.
3. BUILDING EXTRACTION
The maximum DMP response indicates well with a matched SE
value that the pixel resides within. There were 3 differential
morphological opening profiles that were created using square
to 15m (step size was equal to 4m). The SE that less than 7m
was not reliable for use because they consist of small shadows
and rubble of buildings. Because those figures give noise for the
classification results, we used SE more than 7m to detect remain
Buildings. Most of the bright building roofs gave the maximum
response to the opening, roads and dark shadows were
responded shape morphological elements with square size (s)
increasing 7 to the closing.
(f) Opening s-7
(g) Opening s=ll
(e) Opening s=15 (h) Opening s=15
Figure.3 Images (c) to (e) represent binarized structural
decomposition of the pre-event image differential
morphological profile and (f) to (h) represents post event
differential morphological profile. The images have been
visually enhanced. The derivative has been calculated relative to
a series generated by 3 iterations of the elementary SE with 7-
15m rectangular shape roofs. Derivative of the opening profile
with s=7(c,f), 11(d,g) and 15(e,h) are shown above respectively.
Simple image binarization threshold was applied to each DMP
profiles for noise reduction and avoid misclassification. Figure
3 shows the binarized images of both pre and past event
differential morphological opening profiles. The segmentation
threshold value was set to 70 pixels and then the template
matching based on Hit or miss transform method was applied to
extract correspond building roofs. The data set included 7m x
7m (3m x 3m foreground and 9m x 9m background) , 11m
xlIm (5m x 5m foreground and 13m x 13m background)and
15mx15m (7m x 7m foreground and 17 m x 17m background)
template windows.
4. INTERPRETATIONS AND QUALITY ASSESMENT
The results have shown the usefulness of the proposed method
during detection of various types of building, as illustrated by
the portions given in Figure 4.
@
(k) (n)
Figure.4 Result of the building extraction according to
approached method. Identified buildings are shown in red color,
(1),(1) pre and post event building roofs corresponded to SE=7,
(G),(m) pre and post event building roofs corresponded to
SE=11 and (k),(n) show the pre and post event building roofs
corresponded to SE=15 respectively.
The quality of the results was assessed with exist GIS data (pre
event) and visual inspection following manually labeling (post
event) as ground truth. Although this result appeared to be
slightly high, the confidence measures produced by the
suggested a reliability of pre and post event gives 76.41% and
88.26% in object based accuracy. For the applied area, the