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Basic Information on tvdisp
Task: tvdisp
Purpose: Display an image on a TV device
Categories: visual display
TVDISP is a MIRIAD task to display an image on a TV device.
TVDISP does not clear the screen before it initializes the TV;
see TVINIT for this function.
Key: in
This is the standard name for an input dataset -- usually
an image, though sometimes either an image or visibility dataset
or some foreign dataset format. Some tasks support multiple
input datasets at a time (with wildcard supported) whereas
others can handle only a single one at a time. There is
generally no default input name.
Key: region
the userguide.
This selects a subregion of an image. Multiple subregions can be
selected, which are "ored" together. The following subcommands are
recognized (each of which can be abbreviated to uniqueness).
images(z1,z2)
Select image planes z1 to z2 inclusive. z2 defaults to z1.
quarter(z1,z2)
Select the inner quarter of the image planes z1 to z2 inclusive.
If both z1 and z2 are missing, then all planes are selected. If
only z2 is omitted, z2 defaults to z1.
boxes(xmin,ymin,xmax,ymax)(z1,z2)
Select the pixels within a box with corners xmin,ymin,xmax,ymax.
z1 and z2 are the same as in the "image" subcommand. If z1 and z2
are omitted, all planes are selected.
polygon(x0,y0,x1,y1,x2,y2,...)(z1,z2)
Select the pixels within the polygon defined by the list of vertices.
z1 and z2 are the same as in the "image" subcommand. If z1 and z2 are
missing, all planes are selected. If only z2 is omitted, it defaults
to z1.
mask(file)
Select pixels according to the mask given in the file.
The units of the numbers given in the above commands are, in
general, absolute pixels. But this can be changed (and rechanged)
by using one of the following subcommands.
abspixel
Coordinates are interpreted as absolute pixel values, the default.
relpixel
Coordinates are relative to the reference pixel of the map.
relcenter
Coordinates are relative to the central pixel of the map,
(defined as (naxis1/2+1,naxis2/2+1)).
arcsec
Coordinates are in arcseconds, relative to the reference pixel.
kms
Coordinates in the third dimension are in km/s.
NOTE: This region only permits simple bounding boxes.
The default is to display the entire image.
Key: range
The minimum and maximum range used in scaling. The default is
to use the minimum and maximum values of the image.
Key: tvchan
The TV channel to display the image on. This can be 1 to 3 on
the IVAS; 1 to 2 on the MXAS or XMTV servers. The default is 1.
Key: incr
Only every INCR'th pixel is displayed. This can take from 1
to up to 3 values, giving the increment along the x, y, and z
axis, respectively. The default is chosen such that the selected
region of each image will fit on the screen.
Key: tvcorn
This gives the coordinate where the lower left corner of the
image is displayed. The coordinate system typically runs from
1 to 1024 in x and y, the origin being in the lower left corner.
The default is to center the image on the screen.
Key: server
This is used to specify the TV display device. It is giving in the
form:
type@server
or
type@device
The first form causes a connection to be made with a network
display server, whereas the second form uses local hardware
directly. For the network servers, the server process may have
to be started before invoking the Miriad task -- see below.
Currently supported types are:
xmtv Miriad X server. `server' is the servers hostname.
(use "localhost" if you are not networked)
Normally the xmtv server will be the same host as
the X server. The user will normally invoke the xmtv
server before running any Miriad TV tasks, with
% xmtv
If the X server and xmtv server are on different
hosts, you may need to set the DISPLAY environment
variable on the xmtv server, and use xhost on the
X server.
ivas IVAS (VMS only). `device' is the VMS device name.
You will require an IIS IVAS for this.
ivserver IVAS server. `server' is the servers hostname.
Servers are currently installed on
castor.astro.uiuc.edu and bkyast.berkeley.edu.
msss Miriad Sun Screen server. `server' is the serving
Sun, which can be any Sun with a console. The user
will normally invoke the server before running
any Miriad TV tasks, with
% msss
mxas Miriad X server. `server' is the servers hostname.
This is an inferior server to xmtv.
There is no default for the server.
Key: options
These indicate extra operations that may be performed. One or
more can be given. Possible values are:
fiddle Allow interactive modification of colour tables, zoom,
etc. NOTE: The Fiddle option currently only works
with the IVAS servers!
zoom Zoom in on the displayed images. NOTE: Zoom attempts
to display the bounding box of all of the displayed
images. If more than one channel was loaded, then
the zoomed display will be of the first channel.
movie Display the sequence of images as a movie.
NOTE: Movie will attempt to zoom onto one image and
then center the display step by step through each
following image (and then return back to the first
image to begin again). The rate at which the images
will change is a function of the cursor's X position.
The further to the left of the display that the cursor
is located, the faster the rate of change; the further
right, the slower. NOTE: some displays require a
mouse button press to identify the cursor position.
Functions to control the direction and style of motion
are available if the panel is present. If not, a
subset of functions will be available to the four
functions A - D (may also be keys F3 - F6).