Help for GRIDGEN


PURPOSE:

   GRIDGEN is VICAR applications program which generates a synthetic
   grid target consisting of uniformly spaced horizontal and vertical
   grid rulings.  The program is used for geometric calibration of
   vidicon/CCD camera systems.

EXECUTION:

        GRIDGEN OUT=GRID PARAMS

Parameters are defined in the TUTOR mode. SIZE is ingored.
OPERATION:

   GRIDGEN has two operating modes: (1) in the default mode, the output
   consists of a grid location file in MARK format; (2) if the keyword
   IMAGE is specified, the output consists of a gridded image.

   The grid is specified by giving the line-sample coordinates of
   the upper-left-most grid intersection (see parameters GSL and GSS), the
   grid spacing (see parameter INC), and the number of horizontal and
   vertical grid rulings (see parameters NROW and NCOL).

   The grid location file contains the line-sample coordinates of each
   grid intersection is stored in a single record as ordered pairs of floating
   point numbers: L1,S1,L2,S2,L3,S3,...,Ln,Sn where n=NROW*NCOL.
   The rows are ordered from top-to-bottom, and the columns from left-to-
   right.  The intersections of the top-most row are stored first, followed
   by the second row, etc.

   If IMAGE is specified, the user may specify the DN value of the grid
   rulings and the background (see parameters DNGRID and DNBACK).

EXAMPLES:
   The following statement will generate a mark format file containing the
   intersections of a 20x20 grid of rulings spaced 40 pixels apart (all
   values represent the defaults):

         GRIDGEN OUT INC=40 GSL=20 GSS=20 NROW=20 NCOL=20

   The following statement will generate a grid image with grid rulings of
   5 DN overlayed on a background of 240 DN:

         GRIDGEN OUT INC=40 GSL=20 GSS=20 NROW=20 NCOL=20 DNGRID=5
        +       DNBACK=240 'IMAGE

RESTRICTIONS:

   NROW*NCOL must be less than 1200.

PROGRAM HISTORY:

   01 July 1994...CRI ...........Made portable for UNIX
   21 Sep  1987...G.M.Yagi.......Extensive changes
   27 MAR  1985...M.E.MORRILL....ADD OUTPUT OF GRID IMAGE
   30 OCT  1984...M.E.MORRILL....CONVERSION TO VAX-VICAR*2
   06 MAY  1983...M.E.MORRILL....INITIAL RELEASE IBM 

   Written by: Mike Morrill
   Current cognizant programmer:  Gary Yagi