#example2520#
A number of other commands (e.g., MARKSTAR) will also interact with the
display for specific purposes, such as measuring image profiles.
The first time the TV command is given, VISTA opens an Image Display
window on the console, and loads a color map as well as displaying the
image. A ;SPMquot;Zoom;SPMquot; window is also opened that shows a magnified section of
the image under the current cursor location (a kind of ;SPMquot;magnifying
glass;SPMquot;).
Once an image has been displayed, the Display window will accept
interaction asynchronously of commands in the VISTA command window,
provided that a wait for input, or any other I/O is not pending. To
interact with the image, simply move the mouse onto the display window.
The current pixel location of the cursor will be displayed in a frame at
the base of the image display along with the pixel intensity. The arrow
keys are used for find control (one pixel at a time) of the cursor
position.
The following mouse buttons and keyboard keys are active while the mouse
is located on the image display:
<#2528#>
Mouse Buttons<#2528#>
Button |
Function |
LEFT |
ZOOM IN, centered on the cursor |
MIDDLE |
ZOOM OUT, centered on the cursor |
RIGHT |
PAN, move the pixel under the cursor to the center |
<#2534#>
Keyboard Commands<#2534#>
Key |
Function |
R |
RESTORE image to the original zoom/pan |
+ |
BLINK Forwards through the last 4 images. |
- |
BLINK Backwards through the last 4 images. |
P |
Find the PEAK pixel near the cursor jump the cursor there |
V |
Find the LOWEST pixel (;SPMquot;Valley;SPMquot;) near the cursor jump the cursor there |
# |
;SPMquot;Power Zoom;SPMquot; zoom at the cursor to the maximum zoom factor |
H |
Toggle between small and full-screen cross-hairs |
F |
FREEZE/UNFREEZE the Zoom window. |
0-9 |
Mark the pixel coordinates and store in VISTA |
;SPMnbsp; |
variables Rn and Cn, where ;SPMquot;n;SPMquot; is the number key hit |
] |
Clear boxes and stuff off the image display |
Other commands may use additional keys, but this set is always available.
The ITV command is still useful in procedures for making VISTA wait for
pixels to marked on the screen. If ITV or any other VISTA routine is
waiting for screen input, the the INPUT status light is lit (which
otherwise says ASYNC). ITV can also be used to print out pixel values in
the VISTA window or for marking up features on the display with boxes or
circles.
When VISTA is CPU bound (busy doing an intensive calculation), the display
will be put into a wait state before any interactive commands to the
display or ``damage'' from other windows can be serviced. A note for
programmers: CPU intensive routines should have the LOOPDISP call inserted
into them to permit occasional servicing of display window events. See the
VISTA Programmer's Guide for details.
<#2539#>Color Bar Adjustment:<#2539#>
If you place the mouse on the color bar, these commands are available
to adjust the contrast of the image:
#example2540#
The position of the mouse cursor displays the range of intensities
represented by that color.
Pressing the R key while the mouse is on the color bar restores the
original color map (undoing any change of the contrast or ;SPMquot;roll;SPMquot; changes
made with the mouse buttons).
<#2545#>X-Windows Resources:<#2545#>
The properties of the TV display window are defined by Resource variables
that can be customized by making appropriate entries in your .Xdefaults
file. The resource variables are of the form:
verbatim315#
where ;SPMquot;xvista;SPMquot; is the resource name.
<#2549#>
Vista Display Resource Variables<#2549#>
Resource |
Description |
Default |
xvista.maxwidth |
Max width of displayed images |
1024 |
xvista.maxheight |
Max height of displayed images |
865 |
xvista.resize |
Auto-resize the window on display |
1 |
;SPMnbsp; |
of large images up to the max size. |
;SPMnbsp; |
;SPMnbsp; |
1=auto-resize [default] |
;SPMnbsp; |
;SPMnbsp; |
0=no auto-resize |
;SPMnbsp; |
xvista.autozoomout |
Automatically zoom out images larger |
0 |
;SPMnbsp; |
than the max size so that the whole |
;SPMnbsp; |
;SPMnbsp; |
image is visible. |
;SPMnbsp; |
;SPMnbsp; |
0 = no zoom out [default] |
;SPMnbsp; |
;SPMnbsp; |
1 = auto zoom out |
;SPMnbsp; |
xvista.zoomsample |
Selects the de-zoom algorithm |
1 |
;SPMnbsp; |
1 = fast pixel-sampling [default] |
;SPMnbsp; |
;SPMnbsp; |
0 = slower pixel-binning |
;SPMnbsp; |
The following are recommended values to place in your .Xdefaults file:
verbatim316#
These will keep the TV window from obscuring too much of the screen, and
enable the fastest auto zoom mode.
Note that for changes to the .Xdefaults file to take effect, you either
have to log out and log back in again (brute force), or load the changes to
your .Xdefaults file with the Unix ;SPMquot;xrdb -load;SPMquot; command.