International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B4, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
1.1 Image fusion
The fusion of panchromatic with multispectral WorldView-2
scenes was done using the Principal Components method,
resulting in an image with 0.50 m spatial resolution.
1.2 Orthorectification
The orthorectification was made using the 3D rational
polynomial method (TOUTIN, 2004) and the software package
PCI Geomatics v10.3.1, considering 55 GCPs for the entire
area under study. The GCPs used for the geometric
rectification were obtained during a field campaign in August
2011.
1.3 InterIMAGE
InterIMAGE is a knowledge-based free software for image
interpretation. It was developed in the frame of a cooperation
project between INPE, the Brazilian National Institute for
Space Research, the Laboratory for Computer Vision of the
Catholic University of Rio de Janeiro (PUC-RJ), and the
Leibniz University of Hannover (Germany). According to
COSTA et al. (2010), its knowledge structure, design and
control mechanisms were inherited from the German system
GeoAIDA (BUCKNER et al, 2001), which consists of a
further development from AIDA (Automatic Image Data
Analyzer).
According to RIBEIRO (2010) the most important
characteristics of InterIMAGE are its flexibility for the
interpretation of multi-sensor images, the reduction of
computer processing time and the load for the image analysis
(Figure 2).
The most recent version of InterIMAGE can be downloaded at
link htip//vwww.ivc.ele.puc-rio.bi jects/interimage/. Among
other operators for object extraction it contains: a segmenter
from Baatz, the Checkerboard, a classifier by decision trees, an
importer for vector files, topologic attributes which can be used
at the decision rules of Top-Down and Bottom-Up operators
(COSTA et al., 2010).
external operators : |
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Figure 2- Components of the analysis process.
Source: Adapted from RIBEIRO (2010)
2. AREA UNDER STUDY
The area under study is part of the Maranhäo Island, NE
Brazil, encompassing 831.7 Km? (Figure 3).
At the northern section of Säo Luis municipality there are
fragile geologic structures of Quaternary age, which eases
landscape changes by relief modeling agents of climatic,
hydrologic and oceanographic origin. A detailed description of
this area is found in SOUZA & FEITOSA (2009) and GERCO
(1998).
Figure 3 — Localization of test site
Source: Adapted from WorldView-2 image dated July 10^
2010.
3. METHODOLOGY
The main methodological steps are presented in the
flow diagram at Figure 4:
XS Images WV-II
FUSION
:
Fused image
Pan Image WV-II
Control Points
Field Survey ORTHORECTIFICATION
to obtain GCPs for
DGPS system v
DEM Ortho-rectified
Images
NDVI
SEGMENTATION
CLASSIFICATION
EVALUATION OF RESULTS
LAND COVER MAP
Figure 4 — Methodological steps
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