Montage: The Astronomer's Toolkit for Building Image Mosaics and Analyzing Image Metadata

Montage (http://montage.ipac.caltech.edu) is an Open Source toolkit, distributed with a BSD 3-clause license, for assembling Flexible Image Transport System (FITS) images into mosaics, according to the user's custom specifications of coordinates, WCS projection, spatial sampling and rotation. The toolkit contains utilities for reprojecting and background matching images, assembling them into mosaics, visualizing the results, and discovering, analyzing and understanding image metadata from archives or the user's images. Montage is written in ANSI-C and is portable across all common *nix platforms, including Linux, Solaris, Mac OSX and Cygwin on Windows. The distribution contains all libraries needed to build the toolkit from a single simple "make" command, including the CFITSIO library and WCS tools. The toolkit is in wide use in astronomy to support research projects, and to support pipeline development, product generation and image visualization for major projects and missions; e.g. Spitzer Space Telescope, Herschel, Kepler, AKARI and others. Montage is used as an exemplar application by the computer science community in developing next-generation cyberinfrastructure, especially workflow framework on distributed platforms.

Version 4.0 provides dedicated modules that support building and managing mosaics of data cubes; creation of custom PNG and JPEG images (with AVM tags) with command-line user control over the image attributes (stretch, coordinate overlays, coordinate grids, …), and a beta version of a Python wrapper to support creation of PNG and JPEG images. A future release will include, e.g., support for HEALPix.

Montage was funded from 2002 to 2005 by the National Aeronautics and Space Administration's Earth Science Technology Office, Computation Technologies Project, under Cooperative Agreement Number NCC5-626 between NASA and the California Institute of Technology. The Montage distribution includes an adaptation of the MOPEX algorithm developed at the Spitzer Science Center. Montage is now funded by the National Science Foundation under Award Number NSF ACI-1440620.'