CCSD3ZF0000100000001NJPL3IF0PDS200000001 = SFDU_LABEL
RECORD_TYPE                    = STREAM
PRODUCT_CREATION_TIME          = 1991-08-01
OBJECT                         = TEXT
   NOTE                        = "Description of VAX/VMS Workstation 
      				  software provided with the MDIM 
				  CDROM collection."
END_OBJECT                     = TEXT
END

                     VAX/VMS WORKSTATION INTERFACE
                    ------------------------------


Although the software contained on this CDROM have been used and tested,
no warranty, expressed or implied, is made by NASA, the Jet Propulsion
Laboratory (JPL), or the United States Geological Survey (USGS) as to
the accuracy and functioning of the software and related materials, and
no responsibility is assumed by NASA, JPL, or the USGS.

This VAX/VMS workstation software is a highly-simplified example program
for display of MDIM images located on CDROM media. The program is
designed to demonstrate how to extract image data from an MDIM file and
then display the data.

The program was developed exclusively for a VAX-station with a GPX color
display. See Micro-VMS Workstation Software: Graphics Programming Guide
(version 3.0, May 1986) for a description of the graphics routines used
in this program.

The program assumes there is a standard VAX/VMS software  interface to
the CDROM disc. Currently, under version 5 of VMS there is not a system
interface to the ISO/CDROM standard. However, there is a DEC beta-test
version CDROM interface, "VFS Mount Field Test Tool Kit", that provides
access to ISO standard disks. The driver software is not generally
available from DEC. It can be obtained from Jason Hyon, PDS, at the 
following address:
 
    Jason Hyon
    Jet Propulsion Laboratory
    MS 168-514
    4800 Oak Grove Drive
    Pasadena, CA 91109

The program functions as follows:

1) MDIMDISP will prompt the user for the desired size of the window 
   used for display of the image. The default display size is 15 
   centimeters.

2) Next the user is prompted to input the name of the CDROM image file
   to display. 

3) The display window is then created for eventual display of the
   image data.  

4) The program reads the entire image into memory.

5) An "auto-stretch" is performed on the image data to generate an
   optimum display of the data. 

6) The image is then sent to the display window.

7) The program prompts the user for the next image to display.

The program works best with the 1/64-th degree scale MDIM images 
because these images fit nicely into the default window size. It is
possible to display larger images with MDIMDISP. However, only a part of
the whole image can be viewed at any given time. The program initially
displays as much data as can be viewed in the display window. The
lower-left part of the image will be displayed. Other parts of the image
can be display by altering the size of the window with the mouse control
(the standard mouse control features are utilized.)

The program can be complied and linked by first copying the source code
MDIMDISP.FOR to a magnetic disk file and then providing the commands:
$FOR  MDIMDISP
$LINK MDIMDISP

This program was adapted from the CDIMAGE software created by
Robert Mehlman at UCLA/IGPP.