programs which support FITS

[William Pence]

Bob Denny wrote [to Bill Cotton]:
> 
> I just wanted to thank you for FITSView! There's a lot of great technology
> hidden behind its modest user interface. I am just about to release some
> amateur/educational software that generates and uses WCS, and I have used
> your program tons of times myself and for demonstrations to show why
> everyone should be using WCS. Your histogram EQ is virtually perfect for
> eyeball work without having to adjust the B and C controls.
> 
> The port of fv from the FITS Tools is abysmal as far as its user interface
> goes. It won't even fit on an 800x600 screen, and the controls are
> unbelievably baroque. Just try blinking images :-) Plus it has to install a
> monster load of emulation junk just for that one program.
>

Bob,

Sorry you didn't have a good first impression of fv.  First, make sure that
you are using the latest 2.5 version that was released in May 1999; it sounds
like you may have an old version.

Fv is designed to view and edit any FITS file, possibly containing multiple
tables and/or images, so the user interface has many menus and options.  
There is a short tutorial/user's guide available from the fv web site that
explains how to use many of the features for new users.

As for fitting on an 800x600 screen, you can select a default image window
ranging from 300x300 to 700x700 pixels in size, which should suit any screen
resolution.  Regardless of the default size, you can interactively resize the
images by dragging a corner with the mouse.

Blinking of 2 images can be done very quickly and easily: open and display
both images (they initially appear side by side on the display canvas), click
on the 'merge graphs' option to combine both images in the same graph, then
click on 'blink images' to start the blinking.  You can blink any number of
images at one time (not just 2), and the position registration of the images
is determined by the WCS information, so the images do not need to have the
same size or scale.  You can also pan and zoom within the images while the
blinking is in progress.

Other useful image display features in fv are:
 
  - draws a grid of RA and DEC lines over the image
  - contour plots can be generated and combined with other
    images (e.g., draw optical contours on top of a radio image)
  - brightness/contrast and panning/zooming are interactively
    adjustable by dragging the mouse over the image
  - 20 different color mappings, and 3 different intensity scaling
    options (linear, log, or square root) are provided.

Histogram equalization is not currently provided, but that is high on the list
of enhancements for the next release.

Finally, the installation of fv is intended to be easy and quick.  The windows
.zip file is only 2.6MB in size.  Fv is written in native Tcl/Tk code, so it
is not an emulation.

So, we hope you will give fv another try. It is available from the fv web site
at:

http://legacy.gsfc.nasa.gov/ftools/fv/

We can also send a version on CDROM to Linux PC users.  Any questions,
problems, or suggestions about fv should be sent to:

ftoolshelp at athena.gsfc.nasa.gov

regards,
Bill Pence 
(for the ftools group)