Help for ISIS2VIC

PURPOSE: ISIS2VIC converts ISIS cube files to VICAR image files.  All
ISIS data formats are supported.

EXECUTION:

   isis2vic INP=isis.cub  OUT=vic.img  SFROM="::3,9,12"
or
   isis2vic FROM=isis.cub  TO=vic.img  SFROM="::3,9,12"

FROM and TO are the ISIS synonyms for INP and OUT, respectively.  Both of the
above examples will extract bands 3, 9, and 12 from the ISIS cube and output
them to the VICAR image.

ISIS2VIC uses ISIS libraries to read the ISIS image cub file and to
read the cub label.  The ISIS libraries are currently only available for
UNIX Solaris. Therefore ISIS2VIC can only be used on Solaris.

OPERATION:

The ISIS map label infomation is transfered into the VICAR label as a VICAR
mp object and converted to a format compatible with the VICAR mp routines.
The entire ISIS label is placed in the HISTORY portion of the VICAR label
item: ISIS_CUB_LABEL= as a single VERY long string.

ISIS .cub files can have an unlimited number of bands, whereas VICAR is
currently limited to 3.  The SFROM keyword can be used to request that specific
bands or planes be extracted from the .cub file.  ISIS2VIC can be run many
times over a .cub file to extract all the bands.

The FORMAT parameter specifies the output VICAR data format (default is byte).

Both ISIS and VICAR routines are used in the data conversion.  If the output
format is 'BYTE', ISIS handles the conversion entirely.  For all other cases,
ISIS converts the input data to floating point, translates special pixel
values, and then lets VICAR convert to the requested format.

The recommended FORMAT is 'REAL' for all ISIS data types as this preserves the
actual ISIS data value with special pixel translation, which is also always
recommended.  If you do not provide special pixel conversion values and allow
VICAR to convert to a different output format, chances are ISIS2VIC will fail.

The TAE parameters NUL, LRS, LIS, HIS, and HRS, correspond to the
ISIS special pixel values of NULL, LOW_REPR_SAT, LOW_INSTR_SAT,
HIGH_INSTR_SAT and HIGH_REPR_SAT, respectively.  The default for
these values is "NO_CHANGE" which means that special pixel values
are retained during the conversion process. 

It is highly recommended that values be supplied for these
parameters because these special pixel values are represented
as extremely large negative numbers (the largest representable
negative floating point number).  These values should be supplied
as values less than and greater than valid data for saturation
values and a resonable "no data" VICAR pixel value for the proper
output pixel type.  NOTE that when the output VICAR data type is
'BYTE', these values are ignored since ISIS 8-bit pixel values
follow the classical image processing scheme where 0 is no data
or low staturation and 255 represents high saturation.  All other
other output data types are convert to the ISIS floating point
representation (if ISIS data type is standard) and then the
translations are performed of these special pixel values.
The author of the .cub file will need to provide any special pixel
values used in the creation of the .cub file

The default configuration looks for an ISIS MAPLIB map label object.
If the label does not contain a MAPLIB object there can be error 
message generated which is not fatal. In this case set MAP_LABEL=OFF,
then ISIS2VIC will not look for a  MAPLIB object and will not write
a VICAR MP label object.

PROGRAMMER'S NOTES:

This program is designed to run in the ISIS or VICAR or a shared
ISIS/VICAR environment. There is a "#define ISIS" which may be included
in the source file ISIS2VIC.c. If ISIS has been defined the program will
compile to include ISIS initialization code. If ISIS is NOT defined then
ISIS2VIC will use VICAR RTL initialization code. This is the default way to
build ISIS2VIC. If ISIS2VIC is to be run in an ISIS only environment, then
the program should be compiled with ISIS defined.

One of the ISIS subroutines which is called looks for the files planet.sav and
projection_name.sav in the directory pointed to by "ISISDATA".  If these files
can't be found ISIS2VIC will fail.  These files are used in the map label
conversion.  If the parameter MAP_LABEL=OFF is set then ISIS2VIC will not 
attempt to read and convert the ISIS map label and thus this error
will be avoided.

In an ISIS environment these files and the "ISISDATA" variable all
exist.

In a VICAR environment "ISISDATA" is automatically defined (via VICSET)
to point to the ISIS subdirectory under $V2DATA (V2$DATA in VMS).  This
directory contains the files planet.sav and projection_name.sav.

PROGRAM HISTORY:

Original programmer: Steve Levoe JPL, Pasadena, Ca.
  with significant help from: Kris Becker, USGS, Flagstaff, Az.
Cognizant programmer: Steve Levoe
Revisions:  
  AR 9283 - dzs - moved TARGET_NAME into history label
  AR 9032 - dzs - always creates VICAR image with 3 or fewer bands

PARAMETERS: