These instructions describ how to carry out basic image
analysis operations with ds9. Note the following semantics:
| Image Loading |
| Load an existing image into ds9 display
|
Select "File" from top menu
Select "Open Other"
Select "Open Mosaic IRAF..." to get "Open" popup
Select image of choice
Click on OK
|
| Zooming/Panning |
| Set zoom factor (absolute) |
Select "Zoom" from top menu
Release on desired zoom factor
|
| Set zoom factor (relative) |
Click on "Zoom" button
Click on "in" to zoom in
Click on "out" to zoom out
|
| Pan |
Point cursor to the desired new center
Click CENTER mouse button
NOTE: you can click on EITHER the main window or
the panner
|
| Adjusting Image
Scaling/Colormap |
| Adjust contrast/bias |
Place cursor on image
Click and drag with RIGHT mouse
|
| Change scaling |
Click on "Scale"
Click on "zscale" or "zmax"
WARNING: do NOT select "hist equ"!
|
| Set global/local scaling |
For biases and other low-signal frames:
Select "Scale", "Scope", and "Local"
For illuminated frames:
Select "Scale", "Scope", and "Global"
|
| Creating Vector Cuts |
| Create a vector cut |
Click on "Region"
Click on "more..."
Click on "Proj"
Click and drag with LEFT mouse button
Plot window appears
|
| Move a vector cut |
Click on the vector to select
Put cursor on the vector (cursor should change to
 )
Click and drag with LEFT mouse
Plot updates automatically
|
| Change length of a vector cut |
Click on the vector to select
Put cursor on an ENDpoint (cursor should change to
)
Click and drag with LEFT mouse
Plot updates automatically
|
| Change width of a vector cut |
Click on the vector to select
Put cursor on the MIDpoint (cursor should change to
 )
Click and drag with LEFT mouse (NOTE: you can only
expand width in one direction, and the direction depends
on which direction you dragged to define the vector)
Plot updates automatically
|
| Apply an existing vector cut area to a new image |
Define a vector as described above
Click on "Region", then "save" to get "Save As" popup
Enter a filename (or accept default) and click "OK"
Load (or wait for) new image
Click on "Region", then "load" to get "Open" popup
Enter a filename (or accept default) and click OK;
region appears on image
Point cursor to region and double click; popup plot
window appears
|
| Image Statistics |
| Measure centroid/size |
Select "Analysis" from top menu
Select "Simple Stats" to get "stats" popup window
Click and drag with LEFT mouse on image to define a
statistics box
Click on "(re)Compute Centroid" box in "stats"
popup
For greater accuracy, click on "snap to Centroid",
then "(re)Compute Centroid"
Statistics shown include min, max, sigma, center
|
