Section 7: IMAGE DISPLAY

How can I generate or display an RGB image?

 	Typically to do color composite imaging (RGB), you need a display
with 24 bit hardware, with 8 bitplanes each for red, green, and blue.  The
RGB task in IMAGES.TV displays an rgb picture from 3 separate images only on
the 24-bit IIS model 70/75 or Gould Deanza Image Displays, not on 8-bit
workstation monitors.
	In addition, the EXPORT task in DATAIO is capable of combining
images and producing either 8-bit pseudocolor or 24-bit images of various
formats (rasterfile, gif, EPS, etc).  Once the 24-bit image has been created
it may be displayed in 24-bit mode using a program such as XV, although
without the control you may have with display in ximtool.  For more
information or questions contact site support.

What is the proper value of "stdimage" for use with SAOimage or XImtool?

	The 'stdimage' environment variable defines the frame buffer
configuration used for image display.  The form of this value is generally
an 'imt' prefix followed by the configuration number (or an equivalent
alias), available configurations must be defined in both the dev$graphcap
file as well as the dev$imtoolrc file.  Check the latter file for a list
of available frame buffer configurations, or by simply typing GDEVICES
at the CL prompt.

How can I change the size of the frame buffer from the CL?

	Simply by changing the value of 'stdimage' then re-displaying the
image.  To find out what frame buffer configurations are supported use the
GDEVICES command, for example
	cl> gdev
        #                        ALIASES    NX   NY  DESCRIPTION
                                    imtx   512  512  Imtool display server
                      imt1 imt512 imtool   512  512  Imtool display server
                             imt2 imt800   800  800
				   :        :    :      :
	cl> reset stdimage = imt800
	cl> display dev$pix 1

What do I change to add a custom frame buffer size?

 There are two files that need to be modified to create your own frame
buffer size, imtoolrc and graphcap.  You will need to restart the display
window to activate these changes.
  o First you need to copy over the system imtoolrc file into your home
    directory, and then modify the file so it reflects your new frame
    buffer size.  Note the name change during the copy.
       % cd
       % cp /iraf_path/dev/imtoolrc .imtoolrc
       % vi .imtoolrc
    Go to the end of the file and add an entry for your particular frame
    buffer following the examples in the file (contrary to what is in the
    file, keep you frame numbers less than 64).
  o Next, copy over the system graphcap file and edit it in a similar fashion
    following the examples under the "STDIMAGES devices" section.  Now when
    you log into IRAF point to this new graphcap file, and then reset the
    value for stdimage.
       % cp /iraf_path/dev/graphcap mygraphcap
       % vi mygraphcap
       [restart the display window and log into the CL]
       cl> reset graphcap = /home_path/mygraphcap
       cl> gflush
       cl> reset stdimage = my_new_frame_buffer
    When editing the graphcap entry be sure to modify the ":cn" (configuration
    number) field as well as the buffer sizes (the :xr and :yr fields as well
    as the DD string).  After resetting the graphcap environment variable be
    sure to type a 'gflush' to reinitialize the graphics system.

How do I get a hardcopy of an image displayed with XImtool or SAOimage?

 XImtool contains a 'Print' setup panel which can be used to set the output
device or hardcopy options.
	With SAOimage it's the 'Print' button after hitting 'Etc', the
hardcopy is generated by execution of a user configurable command known as
the R_DISPOSE string.  SAOimage requires that R_DISPOSE be defined before
starting SAOimage.
For Unix systems, R_DISPOSE is defined as a Unix environment variable.
It is usually best to define this variable in the .cshrc file since
it will then be valid for any window or menu that starts the display server,
otherwise it must be defined in the same shell (window) that starts
saoimage.  Typical values are:
    setenv R_DISPOSE "lpr -Plw -r %s"		# default string
    setenv R_DISPOSE  'lpr -Plw5 -r -s %s'	# send to printer 'lw5'
    setenv R_DISPOSE  'mv %s $HOME/plot.ps'	# move to home dir
With VMS, the R_DISPOSE command is defined as a global symbol, as in
	$ R_DISPOSE :== print/queue=postscript/delete "%s"
The symbol typically gets defined in the SAOSETUP.COM file, which is run as
part of the SAOimage start up procedure.  See host$x11/run/saosetup.com for
more information.
If the R_DISPOSE string is reset from a terminal window care must be taken
that the server is then started from that window (not a window manager menu)
in order for the new value to take effect.

What can I use for image display on a monochrome monitor?

	At this time, the only choice for users in your situation is to use
the SAOimage display server.  SAOimage is an image display server for the X
environment which includes a dithering algorithm that will display images
on some monochrome servers.