Discovery of software systems for composition and their customizability in free and open source geospatial software environments

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Discovery of software systems for
composition and their customizability in free and
open source geospatial software environments A
Case Study

• S.Manthira Moorthi, Indranil Misra,
  R.Ramakrishnan and P.K.Srivastava
• smmoorthi, indranil, rama, pradeep_at_sac.isro.gov.
  in
• Signal and Image Processing Area, Space
  Applications Centre, ISRO
• Ahmedabad-380015
• India

Presented By S.Manthira Moorthi SAC,ISRO,AHMED
ABAD
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contents
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

• Introduction/objectives
• Tool set for Land and Crop Studies
• Free and Open source Softwares (FOSS) as a
  situated software and reuse
• Standard versus non standard requirements
• Geospatial Processing requirements
• FOSS ILWIS capabilities
• FOSS OSSIM capabilities
• Combining Geospatial Tools
• Code Reuse and new developments
• Rapid prototyping versus long term tool building
• Conclusion

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Introduction/Objectives
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

• Task is to quickly build a geospatial tool box
  with rapid prototyping to satisfy an image
  analysts need to quantify per say land use and
  crop studies from the available open source
  projects falling in this category. There are
  many issues to be addressed in such attempts from
  handling data sizes, remote sensing data formats,
  data types, building process chains to taking
  advantage of batch processing capabilities and to
  put software processes in an integrated
  framework. This study brought many insights into
  existing open source geospatial tools, about
  their strengths and weakness.

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Tool set for Land and Crop StudiesDesktop
Geospatial toolbox
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study
Tasks
Data formats
GIS operations
General Image Processing tasks
Georeferencing
Image Registration
Classification
Statistics aggregation

• A desktop geospatial processing toolbox needs to
  have an elaborate framework with workflows
  comprising data preparation, analysis and
  presentation tasks taking raster and vector data
  as inputs.

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Popular FOSS

• QGIS
• Multi Platform
• Many Core Features
• Plugin Architecture
• GRASS integration
• OTB integration

Open Source Software Image Map (OSSIM) is a high
performance engine for remote sensing, image
processing, geographical information systems and
photogrammetry.
SAGA's first objective is to give
(geo-)scientists an effective but easy learnable
platform for the implementation of geoscientific
methods.
ILWIS is the Integrated Land and Water
Information System.  As the title suggests, it is
oriented to needs of the environmental science
user community, so it is superlative in its user
interface, analysis capabilities, and  image
presentation features.
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Foss as situated software
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

• In contrast to standard software development,
  situated software usually isnt constructed by a
  team of traditional software developers. Instead,
  its created by users who desire specific
  functionality that mainstream software doesnt
  provide. Typically, its personalized, localized
  software that has evolved organically and has
  been created by the community that uses it. FOSS
  geospatial softwares can be compared to situated
  software, though there can be a good amount of
  overlap of functionalities with Commercially
  Available Off the Shelf (COTS) tools.

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Contd.
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

• situated softwares success lies in its ability
  to accommodate change and remain flexible and
  adaptive, as opposed to traditional software,
  which isnt very forgiving and which operates in
  a well-defined boundary, is costly, takes
  significant effort to develop and maintain, and
  can be difficult to modify. Flexibility comes at
  the expense of quality attributes such as
  performance, security, and availability. As an
  example, most reuse efforts and techniques focus
  on reuse at design time.

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Geospatial processing requirements
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study
Task ILWIS OSSIM QGIS SAGA Open EV
General Image Processing tasks Good Excellent okay Excellent Okay
GIS operations Good Very limited Excellent Good Good
Data formats GDAL library GDAL library GDAL library GDAL library GDAL library
Data Types Limited types Many Many Many Many
Large raster handling Good Good not good Not good Excellent
Georeferencing Good Very advanced Very Limited Very Limited Very Limited
Image Registration Through geo referencing module Very advanced NIL NIL NIL
Classification Maximum Likelihood NIL NIL Maximum likelihood ISODATA
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Standard versus non-standard requirements
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study
Task Standard Non standard
Format handlers General Raster Geotiff HDF NITF Variants of Landsat Ground Support Operations Working Group (LGSOWG) Committee on Earth Observing Systems (CEOS) format
Georeferencing GUI based and using reference images, maps and external GCPs Reading header GCPs etc, sensor model parameters etc.
Supervised Classification Training sample creation Tools to create training samples by allowing to draw polygons To accept a shape file as a input training sample set directly
Image registration GUI based and using reference images, maps and external GCPs Automatic robust image registration using georefencing information etc.
Image calculus Aggregation Pixel grid based Overlaying a vector layer for doing aggregation under this vector layer and attribute based calculations
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FOSS ILWIS
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

• ILWIS provides a wide range of tools to perform
  operations on spatial data and uses a number of
  table window operations such as distance
  calculations, aggregations, etc. in the analysis
  of attribute data. Retrieval, reclassification
  and measurement operations mostly from the
  starting point in the data analysis process, and
  all these operations can be performed on vector
  or raster map, often in combination with
  attribute data, efficiently in ILWIS. The overlay
  operations form the core of any GIS project which
  is used to combine a number of maps together and
  to generate new information. ILWIS has a powerful
  tool to combine maps, called Map Calculation that
  can combine many maps at the same time using
  arithmetic, relational or conditional operators.

ILWIS is almost a complete tool for image
processing and GIS operations but only for a data
type of 8 bit unsigned char images only
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FOSS OSSIM Capabilities
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

• Designed as a series of high performance software
  libraries, it is written in C employing the
  latest techniques in object-oriented software
  design.
• It has a powerful automatic satellite image
  registration plugin as an extension to OSSIM
  library.
• Though vector and shape file support is present,
  its GIS capabilities are limited.
• Other salient features include rigorous sensor
  modeling, universal sensor models, wide range of
  map projections and datums supported,
  non-destructive, parameter based image chains,
  native file access, precision terrain correction
  and ortho-rectification, advanced mosaicing,
  elevation support etc.

Open Source Software Image Map (OSSIM) is a high
performance engine for remote sensing, image
processing, geographical information systems and
photogrammetry. It has been actively developed
since 1996.
Its API documentation is exemplary. Many of the
applications are available as command line tool
and not integrated into the GUI tool known as
imagelinker
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Combining geospatial tools
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

• FOSS ILWIS is a good choice for all GIS tasks
  with raster and vector data layers, visualization
  and presentation but
• OSSIM library scores better on image processing
  tasks especially on remote sensing images with
  its rich plugin tools on image registration and
  mosaicing.
• ILWIS does not have the capability to classify
  images other than 8 bit images.

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New developments without FOSS A Supervised
Classifier
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study
ILWIS supervised classification module was not
satisfying the custom requirement in this study
because theres no functionality to accept the
training sample data in the form of ESRI shape
file before image classification. ILWIS does not
have the capability to classify images other than
8 bit images.
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Rapid prototyping versus long term tool building
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

• In rapid prototyping, the development simply
  wants to amalgamate functionalities in a non
  cohesive manner. This means accepting tools
  instead of just functionalities and accommodates
  them in tools management architecture. Rapid
  prototyping approach can also be the approach
  taken by not so experienced software developer or
  by an effort not well resourced and there is a
  pressing need for prototyping of potential new
  functionality.

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Conclusion
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study
If the developmental effort is goal oriented and
requirements are sacred, then over and above the
aggregated functionalities from FOSS you need to
build additional functionalities using the
relevant tool APIs or even fresh developments to
satisfy the complete list of functionalities. It
will be an ideal situation to expect any open
source software to satisfy the custom
requirements. An experienced software development
team should be ready to develop functionalities
those are not catered to by any combination of
FOSS.
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References
Discovery of software systems for composition and
their customizability in free and open source
geospatial software environments A Case Study

1. Sriram Balasubramaniam, Grace A. Lewis, Soumya
   Simanta, and Dennis B. Smith (2008) Situated
   Software Concepts, Motivation, Technology, and
   the Future, IEEE Software, November/December 2008
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4. http//www.ossim.org/
5. http//shapelib.maptools.org/
6. http//www.remotesensing.org/proj
7. http//wiki.osgeo.org/wiki/Open_Source_GIS_History
   Software_projects
8. Michel R. V. Chaudron Clemens Szyperski, Ralf
   Reussner (Eds.), 2008 Component-Based Software
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   Symposium, CBSE 2008 Karlsruhe, Germany, October
   14-17, 2008.
9. http//www.itc.nl/Pub/research/Research_output/ILW
   IS__Remote_Sensing_and_GIS_software.html

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Thank you