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PURPOSE
    A vicar application program to provide the sum of a DN's
in an image.

OPERATION

This program takes an input data set and provides the sum of all DN values  
in an image. It works on BYTE, HALF, FULL or REAL images. It also
separately provides the number of pixels, the number of zero values,
the number of postive values and the number of negative values.
Other outputs separately give the sum of all positive values and the
sum of all negative values.

    The SIZE parameter allows you to select a rectangular window in
the image. Otherwise, the entire image is scanned.

    The output goes to TCL variables: NUMPIX, NUMPOS, NUMNEG, NUMZERO
and SUM, SUMPOS AND SUMNEG.


RESTRICTIONS

    1) This program does not work on DOUB images.
    2) This program does not work on multiband images
    3) The image is limited to 20000 lines by 20000 sample images

PROGRAM HISTORY:

Written by: Ray Bambery, 05 August 2011
Cognizant programmer: Ray Bambery
Revision history:

  2011-08-05 - R. J. Bambery - initial release
  2012-06-02 - R. J. Bambery - Removed <tab> in front of continuation
                               lines to make backward compatible with
                               32-bit Linux gfortran 4.2.1, otherwise
                               compatible 64-bit Linux gfortran 4.6.3 
  2012-06-05 - R. J. Bambery - remove unused variable
  2015-11-05 - W. L. Bunch - Migrated to mipl