Help for GTPWARP

PURPOSE
     GTPWARP acts like GTWARP or GTWARPXD in that it converts an input
     image to an output image, matching the mapping of a reference
     image.  Consider the following four cases:
     
        input                 reference               use
       
     1. GeoTIFF label exact   GeoTIFF label exact     GTWARP
     2. GeoTIFF label approx  GeoTIFF label exact     GTPWARP or GTWARPXD
     3. GeoTIFF label exact   GeoTIFF label approx    GTPWARP or GTWARPXD
     4. GeoTIFF label approx  GeoTIFF label approx    GTPWARP or GTWARPXD
     
     For cases 2 through 4, GTPWARP is highly automatic, but will
     depend upon PICMTCH5 being able to do a good enough correlation
     to give the desired result.  GTWARPXD is more general purpose,
     but the user has to come up with a tiepoint data set.
     
     GTPWARP reads the GeoTIFF label of a "master" or "reference" image,
     then reads the GeoTIFF label of the input image.  It calculates
     a set of GEOMV parameters from these.  Then it applies PICMTCH5 to
     the input and reference to get a mesh of matching points that
     specify the deviation of the mappings due to inaccuracy in the
     mappings.  Both the deviations and the mapping are input to routine
     GTWARPXD to warp the input to the output giving an accurate match
     to the "reference" image.
     
     1.  The keyword 'coverinp causes the procedure to map all of the
     input image to an output image that will just contain it.   The
     keyword gorewid allows the user to specify a zero-filled margin
     to make the output a little larger (or negative trims smaller).
	
     2.  The keyword 'coverref causes the procedure to map the input
     image to an output image that exactly matches the "reference" image.
     Some parts of the input can be lost, or huge areas of zero-fill
     could be added to make the images match.  The gorewid keyword has
     no effect in this case.

    Note that if the resolution of the reference image is much lower than
    the input image, you should specify ref_lowres=y. This will
    swap the order of images in picmtch5 which leads to better matches.
	   
CALL
     gtpwarp INPUT OUTPUT REF '(QUALIFIERS) PARAMS
  WHERE:
     INPUT          is the input data set (must have a GeoTIFF label).
     OUTPUT         is the output data set (will have a GeoTIFF label).
     REF            is the reference data set (must have a GeoTIFF label).
     QUALIFIERS     consist of any of the following keywords:
          COVERINP         smallest output that covers the input geographic area
          COVERREF         output exactly matches the reference image.
     PARAMS         interp,nah,nav,gorewid, fftsize.

  
OPERATION

The program calls PICMTCH5 to create a deviation data set
PERFORMANCE

see PICMTCH5 and GTWARPXD.

Restrictions
------------

The input and reference images must have GeoTIFF labels.


Original Programmer: A. L. Zobrist, 10 Dec, 2000
Last Update:         A. L. Zobrist, 4 Sep, 2007     Additional parameters for Tom
Current Cognizant Programmer: A. L. Zobrist

HISTORY
  2021-05-24 WLB - Migrated from AFIDS

PARAMETERS: