Tigger
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Tigger is a FITS viewer and sky model management tool developed as part of MeqTrees, but also available separately. Tigger is written entirely in Python, and features a modern Qt-based GUI for displaying FITS images and overlaying "sky models" (i.e. catalogs). Tigger was initially conceived as a sky model manager, but it was quickly realized that it would be awfully nice if these models could be plotted on top of sky images, so a FITS viewer was introduced and functionality quickly snowballed. |
Tigger as a FITS viewer
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:
Tigger as a sky model manager
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.
Installing Tigger
If you run a supported distribution of Linux, the MeqTrees 1.2 binary release includes a tigger package which may be installed directly from our repositories, using your favourite package manager. See the MeqTrees Downloading page for details.
For unsupported systems, it is fairly straightforward to install it as source code from our svn repository. It's pure Python -- thus no compilation is required -- but you will need to install a number of prerequisite packages first. See README for details.