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1990-07-14
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USAETL, Fort Belvoir, VA 22060-5546 30 March 1990
*** ADRG DEMONSTRATION SOFTWARE ***
INTRODUCTION
This software is used to demonstrate the Defense Mapping
Agency's production ARC Digitized Raster Graphics (ADRG). ADRG is
a raster scanned image of a paper map with 24 bits of color
resolution (8 bits red, 8 bits green, and 8 bits blue) recorded for
each pixel. The spatial resolution of a pixel is 100 microns or
approximately 250 lines per inch. ADRG data is distributed on
CD-ROM.
This software can be used to display ADRG data extracted from a CD-
ROM on PC-compatible computers with EGA graphics. The software was
written in Turbo Pascal 5.0 on a Zenith 248 with MS-DOS 3.21, BIOS
3.37. The data is extracted from the CD-ROM following DMA's ADRG
Specifications, First Edition dated April 1989 (PS/2DJ/100). The
use of software to read the ISO 8211 file format (which I bypassed)
is recommended. The 24-bits of color have been reduced to 4-bits
for display purposes. (This causes considerable degradation of the
original data.)
This program will work for most ADRG production discs. Will not
display properly ADRG data containing ZDRs with null tiles on the
full resolution image file. In addition, the colors that were
selected in this set are applicable to the M745-3906 TLM map.
ADRG IMAGES
Full Resolution Images (FRI) - The FRI represents the scanned data
at a resolution of 100 microns or approximately 250 lines per inch.
A tile represents an area of nearly 2.5 cm. X 2.5 cm. of the
original map. Approximately 15 tiles of 128 X 128 pixels each can
be displayed on the screen using the EGA resolution.
CLASSIFICATION METHODS
To reduce the 24-bit color to the 4-bit color supported by EGA
graphics the minimum distance method was used. This classification
methods do not adequately address the mixed pixel problem. This
problem occurs where a pixel encompasses different colors on the
map and classifies the pixel to a color not found on the map.
The classification method used is fairly crude and do not
reflect the potential quality if additional image processing
techniques were applied to the data.
Minimum Distance Method: In this method, the 24-bit color
space was reduced to a 4-bit color space and mapped into a Peano
curve. Clusters along the Peano curve were manually identified.
Then the color location of each pixel was mapped to the closest
cluster. This method was more time consuming than the
parallelepiped method because distances to each cluster had to be
calculated. It took approximately ten minutes to classify a
screen-full of data.
CATALOG
FILE DESCRIPTION
adrg.rmf This file
egavga.bgi Turbo Pascal driver for EGA graphics card,
should be present in the directory where the
program is executed
tlm.img Non-ASCII file with 15 tiles image
following minimum distance algorithm for
color assignment, may be displayed with
dispany.exe
adrgmain.exe executable program for this demonstration sw
dispany.exe program that will display an image file
specified by the user (tlm.img)
*.pas Turbo Pascal 5.0 source code
MINIMUM HARDWARE CONFIGURATION
The minimum hardware configuration to run the ADRG demonstration
program is:
IBM-AT or compatible
512K RAM
EGA card and display
360K floppy drive
Hard disk with 800K available
CD-ROM reader with ISO 9660 device driver
INSTALLATION
Installation of the software is not required, however all the
files may be copied to a hard disk with the DOS copy command.
To run the demonstration software:
at the DOS prompt, set a DOS environment variable with
the drive letter assigned to your CD-ROM reader (for
example: C:> set CDROMDSK=G , where G is the letter
assign to your CD-ROM reader).
at the DOS prompt, type the name of the executable
program C:> adrgmain
The program will prompt for a user selected filename where the
map image will be saved for future display.
Also, the program will show the limiting coordinates of the
Zone Distribution Rectangle on the disc, and prompt the user
for the latitude and longitude of a point. This point will
be used as a reference to center the area that will be
displayed.
When execution finishes, hit any key to return to the DOS
prompt.
ADDITIONAL INFORMATION
NOTE : The ADRG demonstration software (ADRGMAIN.EXE) can only be
used with the DMA's production CD-ROM's.
For questions or additional information, please contact:
U.S. Army Engineer Topographic Laboratories
Digital Concepts and Analysis Center
ATTN: CEETL-CA-D (Juan A. Perez)
Fort Belvoir, VA 22060-5546
(202) 355-2864
AV 345-2864