Help for VTIFF

   VTIFF is a Vicar2 program, which can be used to convert
   between VICAR labeled images and TIFF format files, using
   either scanline (strip) organization, or the newer Revision
   6.0 TIFF tiled-image format. Currently grayscale, image-
   lookup table pairs and RGB tripletes are supported. In addition,
   multiple auxiliary images may be placed in the same file,
   such as "thumbnail" preview images.

   "TIFF" is a trademark of Aldus Corporation, and is a public
   standard for platform-independent raster-image storage and
   transmission. It is an acronym for Tagged Image File Format.

CALLING SEQUENCE:

	vtiff-tovic   image.tiff  image 	  AUXIL=(files...)
	vtiff-tovic   image.tiff  (image, lookup) AUXIL=(files...)
	vtiff-tovic   image.tiff  (red, grn, blu) AUXIL=(files...)

	vtiff-fromvic  image  		image.tif  [options..]
	vtiff-fromvic  (image, lookup)  image.tif  [options..]
	vtiff-fromvic  (red, grn, blu)  image.tif  [options..]

   where image.tiff is TIFF format, and lookup is a
   color lookup table in IDX format (1024 sample, 1 line
   byte image, with values r1,g1,b1,0,r2,g2,b2,0,...).

   Unlike VMAC, (which this program is intended to partially replace
   as a Unix-portable TIFF converter), no support exists yet to convert
   an RGB triplet into an 8-bit image-lookup pair.

OPERATION

  In the "tovicar" mode, the program unpacks the image and
  lookup table, if desired. It will also unpack any additional
  files and save them as specified by the AUX parameter.

  In the "fromvicar" mode, you have the option of saving the
  files in strip-mode (horizontal scanlines contiguous), which
  makes them TIFF 5.0 compliant; or using the TIFF 6.0 tiling
  option, which breaks the image up into rectangular tiles, and
  saves those in a contiguous manner.

  You may save multiple additional images in the same file using
  the "AUX" parameter. If the file uses a lookup table, you may
  include this in the second INP parameter. It currently must be
  an IDX-format lookup table (1 line x 1024 sample byte image:
  r1,g1,b1,0,r2..). NOTE: Tiling is a new feature, which many
  TIFF programs cant yet handle. If so, use the default strip-mode. 
OPERATION

  You may also chose a TIFF data compression option. The
  currently supported keywords in VTIFF are 'LZW = lempel-ziv-welch
  compression, 'PACKBITS = Macintosh-style packbits (run-length
  encoding) compression, or 'NOCOMP = no compression. NOTE: The
  TIFF 6.0 standard now discourages the use of LZW, as Unisys Corp.
  claims to have a patent on the algorithm, and so may not
  support LZW in the future.

  For RGB triplets, whether tiled or in strips, you may choose
  to organize the data using 'CHUNKY or 'PLANAR interleaving.
  The 'CHUNKY format is analogous to the VICAR BIP (Band-interleaved
  by pixel) organization, and is the default. The 'PLANAR is
  similar to BSQ (Band-sequential) format, and while this permits
  faster conversion and extraction, it is an extension to TIFF
  that is not supported by as many TIFF-compatible programs.
OPERATION

  The latitude-longitude parmeters are extensions to TIFF to
  permit specification of scanned map georeference data. These
  extensions are TIFF-compliant, and will not interfere with
  any standard TIFF-reading program, which will ignore the 
  extended data fields. For more information on the cartographic
  TIFF extensions, contact the Cartographic Applications Group
  at JPL. Do not use these parameters if you only want standard TIFF.

  In general, for the most easily exportable TIFF file, use as many
  of the default values as possible. The parameters are set up so
  that the parameters further down the list will cause the file to
  be less exportable if their default values are overridden.


REVISION HISTORY


   Written by:            N. D. Ritter  September 1991
   Cognizant Programmer:  N. D. Ritter  1991-1992
   Latest revision:       B             March 1993.

REFERENCES

   "TIFF" Revision 6.0, Final - Jun 3, 1992,
      Aldus Developers Desk, available via anonymous ftp
      through sgi.com.
AKNOWLEDGMENT

   This program is a VICAR front-end to a public-domain
   subroutine library of TIFF file format routines, written
   by Sam Leffler, and extended for JPL use by Niles Ritter.
   The source code carries the following copyright notice:

   <quote>
   Copyright (c) 1988, 1989, 1990, 1991, 1992 Sam Leffler
   Copyright (c) 1991, 1992 Silicon Graphics, Inc.
 
   Permission to use, copy, modify, distribute, and sell this software and 
   its documentation for any purpose is hereby granted without fee, provided
   that (i) the above copyright notices and this permission notice appear in
   all copies of the software and related documentation, and (ii) the names of
   Sam Leffler and Silicon Graphics may not be used in any advertising or
   publicity relating to the software without the specific, prior written
   permission of Sam Leffler and Silicon Graphics.
AKNOWLEDGMENT
   
   THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
   EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
   WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
   
   IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
   ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
   OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
   WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
   LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
   OF THIS SOFTWARE.

   <unquote>.