; OFMCONT
;---------------------------------------------------------------
;! creates/modifies TV color OFMs with level or wedged contours
;# Verb TV-appl
;-----------------------------------------------------------------------
;;  Copyright (C) 1995
;;  Associated Universities, Inc. Washington DC, USA.
;;
;;  This program is free software; you can redistribute it and/or
;;  modify it under the terms of the GNU General Public License as
;;  published by the Free Software Foundation; either version 2 of
;;  the License, or (at your option) any later version.
;;
;;  This program is distributed in the hope that it will be useful,
;;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;  GNU General Public License for more details.
;;
;;  You should have received a copy of the GNU General Public
;;  License along with this program; if not, write to the Free
;;  Software Foundation, Inc., 675 Massachusetts Ave, Cambridge,
;;  MA 02139, USA.
;;
;;  Correspondence concerning AIPS should be addressed as follows:
;;         Internet email: aipsmail@nrao.edu.
;;         Postal address: AIPS Project Office
;;                         National Radio Astronomy Observatory
;;                         520 Edgemont Road
;;                         Charlottesville, VA 22903-2475 USA
;-----------------------------------------------------------------------
;---------------------------------------------------------------
OFMCONT   LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
OFMCONT: Verb to create/modify TV OFMs w wedge/level contours
DOWEDGE       -128.0       128.0   > 0 => wedges, <= 0 level
                                   abs value => # of contours
DONEWTAB        -2.0         2.0   >  0 => make new OFMs
                                   <= 0 => modify current OFM
TVLEVS          0.0      1024.0    Peak intensity at OFM
          Instructions will appear on terminal.
----------------------------------------------------------------
OFMCONT
Type:     Verb
Use:      The image intensities stored in the memory of the TV
          display are translated by 2 "look-up-tables" in
          succession.  The first is used by AIPS mostly for
          simple linear black-and-white enhancements (TVTRANSF)
          and is called the LUT.  The second is used to apply
          the gamma correction (see GAMMASET) and to display
          pseudo coloring (TVPSEUDO) of the image and is called
          the OFM ("output function memory").  OFMCONT modifies
          an existing OFM or creates a new one, dividing the
          intensity range into a number of equal size ranges or
          "contours".  Each contour may be a wedge (0 to max)
          from beginning to end of each contour intensity range
          or each contour may be a level constant.

          The verb begins by drawing in a graphics plane the
          color wheel, ranging from green at the top through
          cyan, blue, magenta, red, and yellow in a clockwise
          fashion.  It also places the contour level numbers
          in a column at the left and begins a plot of the
          intensities at the top.  To select a contour level to
          be modified, move the cursor to one of the numbers
          (actually it's only the Y position that matters) and
          press a button.  Button C specifies that the contour
          should be changed to black and white (or levels of
          grey).  Button A or B start an interactive session in
          which the intensity and the hue/saturation of the
          contour are set.  Button A starts with hue/saturation
          and button B with intensity.  While hue/saturation are
          being set (by moving the cursor around inside the
          wheel), button A will allow you to select in the other
          half of the color cube (black vs white in the center
          of the circle), button B will switch to intensity
          setting, and button C will freeze the values allowing
          you to select another contour.  While intensity is
          being changed (by the Y position of the cursor),
          button A will switch to changing hue/saturation and
          button C will freeze the values allowing you to select
          another contour.  While you are changing the hue,
          saturation,a nd intensity, the values you have chosen
          are plotted at the top of the TV screen.  Button D
          terminates the session at any time.
Adverbs:
  DOWEDGE.....Specifies the number of contours and the type:
              <= 0 => use level contours,
              >  0 => use step wedge contours,
              ABS (DOWEDGE) => number of contours (default 8)
  DONEWTAB....>  0 => replace the existing OFM with a new one,
              <= 0 => just modify the existing OFM as specified
                      with the buttons and cursor.
  TVLEVS......Specifies the maximum intensity expected for the
              sum of all visible, overlapped images.  Usually
              256, 512, 768, or 1024.
----------------------------------------------------------------
