Rule-Based Aggregation of Classified Imagery
MegaMerge - MM5.2
Ray Ford and Steve Barsness
Distributed Applications and Systems Lab (DASL)
University of Montana
Missoula, MT 59812
OVERVIEW - ABOUT MEGAMERGE (MM5.2)
The software described here, known as MegaMerge (MM5.2) is a specific
version
of rule-based aggregation software produced by the Distributed Applications
and Systems Lab (DASL) at The University of Montana. MM5.2 is being developed
under contract with the USGS - Biological Resources Division to address
the needs of the Gap Analysis Program .MM5.2
is designed to aggregate large remotely sensed datasets representing classified
images, to produce result images in which areas smaller than a specified
threshold
minimum
mapping unit (MMU) size have been "merged" with their most similar
neighbor.
Key Features
-
Hierarchical scaling : MM5.2's aggregation process is hierarchical
in nature, i.e., assuring that important area boundaries remain intact in
successive aggregations at increasingly large MMU.
-
Local parameterization: MM5.2 allows the user to set the MMU
value, to select between a 4-way or 8-way definition of neighbor, to define
numerical similarity between class value pairs, and to specifically include
or exclude portions of the image from processing (by value or by image location).
-
Local processing: MM5.2 is designed to process imagery on
a local Unix workstation (e.g., from Sun, IBM, SGI, HP, DEC, or others)
-- it does NOT require a supercomputer.
-
Specific hardware requirements :MM5.2 will run with as little
as 32MB of RAM for processing small to medium-sized images. A system with
196-256MB of real memory and256-500MB of virtual memory/swap space is required
to handle large images effectively, e.g. up to 8000 x 8000 pixels of 8-bit
data.
-
Processing time :Execution time will depend on the speed of
the workstation, size and "complexity" of the image, size of RAM and swap
space, options, etc. -- times generally range from a few minutes to a few
hours.
Further information on MM5.2, including a description of the merge a process,
execution parameters and characteristics, details on how to obtain MM5.2
under the USGS/USFW contractor for other uses, on related versions of "merge",
or
on related software and research/development efforts can be found through
the
Merge Site Index
-
Final
Report Final report on the project of preparing MM5.2 for release to
Gap Users.
-
Merge
Quickstart Short description of the steps needed
to get the code and start using Merge.
-
Merge
Process Description of the process, including the definition of the
image transformation that it implements, the general parameters that control
its operation, the set of features that any implementation might offer, and the general computational costs of the process.
-
MM5.2
Details Details on MM5.2features, parameters,
mandatory/optional
inputs, outputs, etc.
-
How
to Obtain MM 5.2 Details on how to get MM5.2 for your type of workstation,
under
the USGS/GAP Analysis Contract or for other purposes.
-
Merge
Terms/Acronyms
-
Download
Local Copy of Documentation-- a tarred/compressed version of these
Web pages, with documentation on M52/MC52 for local installation.