Documentation
Tigger is heavily influenced by the wonderfully feature-rich Karma/kvis viewer of Richard Gooch, but also borrows ideas from SAO DS9 package, trying to combine these with a modern and (hopefully) less frustrating GUI.
The screenshot below shows off the colourmap control dialog, with (kvis-influenced) histogram-based controls for changing the colour levels, etc. The image display shows the use of a mouse-based "image ruler", and a live mouse position tracker at the bottom of the window.
Tigger uses wcslib to map pixel to world coordinates. One upshot of this is that multiple images (with, potentially, different resolutions and centre coordinates) can be correctly shown (and blink-compared) in the same plot. You can see this in the screenshot below. This also shows off the live zoom & cross-section tools:
There's support for quick on-the-fly image mathematics (see below). Since Python itself is used to parse the expression, rather complicated things may be computed:
Where Tigger really shines is as a sky model manager. A sky model is essentially a source catalog with some extra bells and whistles. Some of the more powerful features here are fairly specific to radio astronomy and to processing in MeqTrees. More generally, Tigger can be used to visualize arbitrary source catalogs (specified as ASCII files), and to superimpose these onto FITS images.
