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IDRISI: The Kilimanjaro
Edition |
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The 14th release of the IDRISI geoanalytic
and image processing system extends the current analytical range
while providing major enhancements in cartographic display.
Features of this upgrade include:
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Display System Enhancements
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| Figure 1. A map composition
created using the new cartographic display features, including
layer blending and transparency, as well as the new image
classification and advanced symbol selection
tools. |
We have implemented a
complete overhaul of the display system - from the unglamorous
low-level internal routines to the very evident control dialogs.
Figure 1 illustrates many of these new features:
- Enhanced Cartographic
Symbolization - Now choose immediate classification
of data into equal interval, quantile and standardized ranges.
Further, the system now provides advanced symbol file selection.
Through simple options for the data type (quantitative,
qualitative or uniform) and varying options for the organizational
character of the data (e.g., unipolar, bipolar, balance), this
simple utility provides direct access to over 1300 symbol themes.
(Figure 3)
- Layer Blending -
Visually merge layers using alpha blending. Figures 1 and 2, for
example, illustrate the case of merging a hillshading layer with
hypsometric tints. This was achieved by highlighting the DEM layer
in Composer and then clicking on the blend button (the left-most
of the new buttons indicated in Figure 4).
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| Figure 2. The
stages in developing raster imagery used above. A hillshaded
layer is displayed in gray; a DEM is added using the new
default quantitative palette and 16 equal interval classes;
Composer's blend function combines hillshading and DEM; a mask
is added with 0's (displayed as black) in the area of
interest; Composer's transparency button allows topography to
be seen through the mask; a 60% blend limits the degree of
transparency within the masked
area. |
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| Figure 3. IDRISI Kilimanjaro now
includes enhanced cartographic
symbolization. |
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Figure 4. The 24-bit
composite was generated on the fly by assigning each of
three layers the appropriate primary color using the new row
of display buttons on Composer. From left to right, these
buttons toggle blend, cyan, red, green and blue primary
assignments, and
transparency.
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Background Transparency - The
backgrounds of raster layers can now be made transparent by
clicking on the rightmost of the new Composer buttons (Figure 4).
Figure 2 shows the effect of transparency in the second to last
panel, and transparency and blend combined in the last
panel.
- Interactive RGB
Compositing - Independently displayed layers can be
designated as the red, green and blue layers of an RGB composite
directly within Composer. To do so, simply select the layer in
Composer and then click on the appropriate red, green or blue
button (Figure 4).
- Scale-dependent
Visibility - Layers can be set to automatically
become visible or invisible depending upon the scale.
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| Figure 5. Using the cyan
and red layer buttons on Composer, it is easy to set up
anaglyphic stereoscopic views from systems such as SPOT,
ASTER or IKONOS (seen here). |
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Figure 6. The new Fly
Through module uses OpenGL to provide real-time interactive
flight over a DEM. |
Anaglyphic 3-D - View stereo
images from ASTER, SPOT or IKONOS in 3-D (Figure 5) using
red/cyan, red/blue or red/green anaglyphic 3-D glasses (each copy
of Kilimanjaro includes a free pair).
- 3-D Interactive Fly
Through - Using the power of OpenGL, Kilimanjaro
brings truly interactive 3-D fly-through to the IDRISI system.
It's quick, simple and dramatic. Specify a DEM and a drape image
and you're ready to fly. The system provides complete control over
altitude, orientation and movement. Competing software systems
sell this facility alone for over three times the cost of a new
license for the entire IDRISI system! (Figure 6)
Interface Enhancements Another
significant development is the introduction of persistent forms. In
previous versions, clicking on the OK button of a dialog would cause
the form to disappear. Now, it remains open with all its settings
until you click the Close button - a great feature when you need to
execute a series of similar operations. For those who prefer the
older style, you can select either interface type in User
Preferences. We have also consolidated a number of modules that were
similar in character but separate because of their sequence of
release. Thus the six raster/vector conversion modules (POINTRAS,
LINERAS, POLYRAS, POINTVEC, LINEVEC, POLYVEC) are now replaced by a
single integrated module. Similarly, the many generic import options
of PARE, BILIDRIS and BIPIDRIS have been collected together. We will
continue to streamline in releases to come.
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| Figure 7. IDRISI's new
database support based on Microsoft's ADO includes special
features for streamlining the import and export of raster and
vector layer data. |
New Database
Support Kilimanjaro also includes a completely revamped
database management system based on Microsoft's ADO technology
(Figure 7). Built from the ground up as a complete replacement for
the previous system, IDRISI's database support is compatible with
all versions of Microsoft Access and can easily import and export
xBASE, CSV and Microsoft EXCEL formats. Database Workshop can now
also connect to any Microsoft OLE database provider (e.g., SQL
Server, Oracle, ODBC, OLAP) providing direct support for distributed
databases. Multiple tables are now supported within one database
with queries made across these relational tables using an Advanced
SQL editor.
Direct links can be made between the database
and the vector layer and between the vector layer and the database.
Of particular significance is the ease with which vector and raster
layers can be exported from and imported into the database - simply
click the mouse in any column and then select the appropriate button
- a highly efficient sequence!
Image Processing IDRISI continues to
develop its high-level support for image classification. Significant
new developments include:
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| Figure 9. NEURALNET
undertakes the classification of remotely sensed imagery
through an artificial neural network classifier using the
back propagation. |
- NEURALNET -
Implements a back propagation neural network classifier. (Figure
9) In cases where class reflectance distributions are not normal,
neural network classifiers have been shown to produce superior
results to parametric classifiers such as Maximum Likelihood.
Although the user has complete control over all parameters such as
the number of hidden layers, the learning rate, and the acceptable
RMS, extensive work has been undertaken to develop a
context-sensitive selection of control parameters. Thus the module
is extremely easy to use. All it requires is a set of training
sites (created with MAKESIG as usual). Note that the new CCA and
PURIFY modules can be used to improve the quality of the training
sites supplied to NEURALNET.
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| Figure 8. The new CCA
module undertakes a canonical components analysis on a set
of image bands specified from input signatures and produces
a new set of optimized transformed
images. |
CCA - Canonical Components
Analysis (CCA) is related to Principal Components Analysis (PCA)
in that it is a transformation of the original band achieved by a
rotation of axes.(Figure 8) However, the intent here is to orient
the axes such that they minimize the within-class variance and
maximize the between-class variance for a set of signatures of
interest. Thus the resulting images enhance the differences
between the classes described by the signature set. CCA has
significant value in the context of visual analysis, but can also
be an important aid to the process of classification using a
neural network.
- PURIFY - As the name
suggests, PURIFY filters training site pixels to remove
unrepresentative cases. Two options are provided - parametric and
non-parametric. In the case of the former, pixels are removed on
the basis of their typicality - a metric derived by
integrating the tail probabilities of the Chi Square distribution
based on the Mahalanobis distance of the pixel from the mean of
its class. Thus, for example, specifying a threshold of 0.01 will
remove all pixels that have less than a 0.01 chance of belonging
to the training site class. With the non-parametric option, PURIFY
performs a cluster analysis within training site classes and
removes all clusters that are smaller than a user-defined
threshold. The parametric option is designed for use with MAXLIKE
while the non-parametric option is designed for use with
NEURALNET.
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| Figure 10. The revised
CLUSTER modules uses raw imagery for unsupervised
classification. |
MAHALCLASS - MAHALCLASS is a
new soft classifier that expresses the typicalities of pixels for
each class. As with all classifiers in the soft classifier group,
MAHALCLASS produces a separate image for each training site class.
In this instance, the images express the probability of finding a
pixel with a Mahalanobis distance greater than or equal to that of
the pixel being evaluated. The Mahalanobis distance is the
multivariate equivalent of a z-score. Thus the measure expresses
how typical (or atypical) the pixel is of the class in question.
The results are thus effective in evaluating the quality of
training sites and the presence of unknown classes. Additionally,
a hard classification can be produced by submitting the images to
the HARDEN module.
- CLUSTER - The CLUSTER
module has undergone a significant revision. (Figure 10)
Previously CLUSTER performed a histogram peak cluster analysis
based on the information in a three-band color composite. In the
new version, you can work with up to seven raw bands. In addition,
you have control over the parameters that control the histogram
peak procedure.
- ISOCLUST - The
ISOCLUST module has also been revamped. In addition to using the
new CLUSTER procedure for seeding clusters, the Iterative
Self-Organizing Procedure also incorporates a threshold for
cluster weeding.
- TASSCAP - The TASSCAP
module now includes options for working with
atmospherically-corrected reflectances and at-satellite
reflectances for LANDSAT data as well as the direct Dn
transformation previously supported.
GeoAnalysis Although our emphasis with
this release was on the interface and display system, IDRISI has
continued to strengthen its base as a geoanalytic system. Our
focus to date has been on developing foundation tools (which we
pledge to continue), but with this release we have begun to direct
our focus towards high level models of significant importance to
resource managers and researchers. This release includes the first
two of a series of well-established models we intend to implement:
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| Figure 11. The Revised
Universal Soil Loss equation (RUSLE) module models soil
erosion. |
RUSLE - Soil erosion is one of
the most significant environmental problems we face today. Without
question, the development of the Universal Soil Loss Equation
(USLE) was a milestone in the modeling of soil loss. More
recently, the Revised Universal Soil Loss Equation (RUSLE)
has been developed by the US Department of Agriculture as the
basis for computing annual average soil loss due to sheet and rill
erosion. Its widespread utilization reflects the equation's
minimal data demands with its success in estimating average,
long-term erosion on field units of relative homogeneity. For many
parts of the world, the advent of improved and inexpensive DEM
generation through softcopy photogrammetry and interference SAR,
along with precise land cover mapping using remotely sensed
imagery, offers significant opportunities for the spatial
delineation of nonchannelized erosion. Where accurate data exist
for the RUSLE variables, the module will permit greater accuracy
and consistency than current field methods. (Figure 11) Several
new modules were developed to implement RUSLE and exist as
stand-alone modules in IDRISI. These include SLOPELENGTH which
calculates the longest slope length within regions, SEGMENT which
produces an image of homogenous slope segments (in gradient and
orientation) and GENERALIZATION for raster image generalization
routines.
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| Figure 12. GEOMOD is a
new predictive land change simulation modeling
tool. |
GEOMOD - Building on its
development of the CA_MARKOV module for land cover change
projection, IDRISI now includes the first Windows implementation
of the GEOMOD predictive land change simulation model. (Figure 12)
Developed at the State University of New York (SUNY) Syracuse,
GEOMOD has been applied throughout the world in a variety of
policy-relevant land-use change modeling studies. GEOMOD predicts
the locations where land is likely to change from one category to
another, for example from forest to non-forest. Specifically,
GEOMOD has been the model of choice to analyze the effectiveness
of forest conservation projects that have been implemented under
international agreements on climate change. The combination of
GEOMOD with IDRISI's statistical modules such as ROC and VALIDATE
allows the user to measure the certainty of scenarios of future
land change. GEOMOD is a significant tool for land cover change
modeling, and this implementation represents a major achievement
in inter-institutional cooperation.
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| Figure 13. The revised
VALIDATE module now supports multi-categorical landuse for
change analysis. |
- VALIDATE - This
version adds a major revision of the VALIDATE module. (Figure 13)
VALIDATE is a map comparison tool designed in particular for
purposes of model projection validation. In our last release,
VALIDATE was introduced with its detailed breakdown of the nature
of agreement according to the degree to which it is attributable
to the specification of quantity, location or chance. With this
release, we extend the analysis to consider scale. A model that is
performing less than satisfactorily at the resolution of
individual pixels may be doing quite well at another scale. This
is important feedback on the scale of the processes operating and
the adequacy of the model.
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| Figure 14. IDRISI now
includes import/export for SPLUS. |
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| Figure 15. Enhancements
to the RUNOFF module include the addition of a permeability
factor for drainage
analysis. |
SPLUS - IDRISI now adds SPLUS
support as a supplement to its existing support for STATISTICA.
(Figure 14) SPLUS is supported in two ways. First, IDRISI offers
full import/export of image and values file data. However, we have
also created an SPLUS library that works directly within SPLUS.
Further we provide the instructions on how to control IDRISI from
SPLUS using IDRISI's COM interface.
- RUNOFF - Another
module that has undergone significant revision is RUNOFF - the
module that determines the flow pattern over an elevation model.
(Figure 15) In the previous version, precipitation was assumed to
be uniformly distributed and all surfaces were assumed to be
impermeable. In the new version, you can now specify both a
precipitation surface and a permeability surface.
Import/Export Since the last full
release, we have developed a series of major import/export
procedures. Some of these were slipstreamed into a patch release
last spring, such as the support for ERDAS Imagine IMG files and
full support for HDF. The HDF reader is a major addition, allowing
the full ingest of ASTER and MODIS data, as an example. (Figure 16)
With this release, we have revised our GEOTIFF support to include
the non-standard (but increasingly used) 16-bit and 32-bit formats.
(Figure 17) As a result, IDRISI now offers support for all IKONOS
and QUICKBIRD data formats. Other new import routines added since
the last full release include support for ERMAPPER data and the
Argentinean satellite SAC-C.
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| Figure 16.
IDRISI supports HDF-EOS 4 format, useful for importing ASTER
data. |
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| Figure
17. The revised GEOTIFF/TIFF module now supports export from
IDRISI to GEOTIFF as well as import/export for 8-bit, 16-bit,
24-bit, and 32-bit GEOTIFF formats, such as QUICKBIRD. |
Network Compatibility and License
Management Network administrators will be pleased to learn
that this version is fully compliant with the new security features
of Windows 2000 and Windows XP. Thus registry changes are no longer
needed to support users who are not part of the Power Users group.
We are also introducing license management with this version of
IDRISI. For network administrators, this will allow the setup and
management of multiple concurrent clients from a single server - a
major improvement in system management. For standalone users,
license management will simply require that they register their copy
within 7 days of installation.
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| Figure 18. Macro Modeler
incorporates dynamic modeling features along with over 100
modeling components. |
Missed Release Two? If you haven't
upgraded from Idrisi32 to Idrisi32 Release Two, the Kilimanjaro
Edition is doubly significant. When you purchase Kilimanjaro, you
also get all of the developments of Release Two, including:
- the most extensive graphical modeling environment in the
industry, including dynamic modeling. (Figure 18) IDRISI's new
Macro Modeler provides a drag-and-drop graphical interface for the
programming of analytical sequences, including the ability to
create and link submodels that extend system functionality. Using
feedback loops, a cellular automata tool and dynamic iteration
structures, users have simple access to the full power of dynamic
modeling. This of course is additional to IDRISI's fully COM
compliant programming interface that allows direct control of
IDRISI from programming languages and scripting tools such as
Visual Basic, Visual C++, Delphi and Python.
- major enhancements to the system's image processing
capabilities, including Linear Spectral Unmixing, Linear
Discriminant Analysis (Fisher Classifier), Automatic Mosaicking,
Full Atmospheric Correction, AOI (flood polygon) training site
delineation, and greatly extended hyperspectral capabilities.
(Figures 19-21)
- an extensive set of new change and time series analysis tools,
including change vector analysis, temporal correlation, Markov
Chain analysis, and a cellular-automata based change projection
procedure.
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| Figure 19.
Atmospheric Correction. |
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Figure 20.
Automatic Mosaicking. |
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| Figure 21.
Probability Guided Linear Spectral Unmixing for sub pixel
classification. |
Why
Kilimanjaro? Mount Kilimanjaro lies very close to the
equator. Only by virtue of its extraordinary height does it carry
permanent snow. However, the evidence is clear that the snows of
Kilimanjaro have been receding. Is this the effect of global warming
or a natural climatic cycle? The debate is passionate and highly
political and its resolution is essential to our ability to carry
out responsible and sustainable environmental planning. However, to
do so, we require innovative and powerful analytical tools. It is
towards the development of these tools that we are
dedicated.
IDRISI is now in its 18th year of continuous
development, and offers the most extensive analytical suite of any
software system in the geoanalytical domain, particularly in the
areas of decision support, uncertainty management, image processing
and change and time series analysis. Built by researchers for
researchers, IDRISI is a professional level tool that represents the
outcome of one of the most extensive and sustained research and
development efforts in the industry, firmly grounded within a
non-profit philosophy.
Perhaps most importantly, IDRISI is
the tangible outcome of a vigorous exchange of ideas. Intellectual
contributions to its development come from a wide spectrum of users,
as is clearly evident in our international network of Resource
Centers. Please join us in our quest for an affordable,
approachable, extensible and innovative platform for responsible
environmental management.
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