SAOimage: The Next Generation

NB: with the release of our new ds9 image display program, we consider SAOtng to be retired. Please upgrade to ds9 at your earliest convenience.

SAOimage is an X Window System image display program that has been used by thousands of astronomers throughout the world during the past decade. In this age of "open software", it needs updating to support:

To add such functionality to SAOimage, we developed the XPA Messaging System that allows X programs to define points of public access through which data and commands can be exchanged with external programs. XPA extends a program's graphical user interface beyond the customary boundaries of the program's window. Actions in a graphical program usually are initiated by mouse and keyboard events input by the user. But using XPA, these actions can be initiated by external programs using the public access programming interface. In addition, new actions that are not part of the GUI can be added to this interface.

We have utilized XPA to develop "SAOimage: The Next Generation" (SAOtng), an extensible image display service that can cooperate with other processes and programs. SAOtng supports advanced features such as:

In addition, through XPA, open software functionality has been added to SAOtng at many levels. All of the SAOtng menu functions are defined to be XPA public access points, allowing SAOtng to be controlled directly through its GUI or externally by other programs. XPA also is used to "externalize" algorithms such as image file access and data scaling, so that new file formats and scales can be added without re-compilation. Finally, XPA is used to support user-configurable "quick-look" analysis of image data and bi-directional communication with other processes.

SAOtng has been ported to Linux, Solaris, SunOS, Dec Alpha OSF1, HP/UX, and SGI. Twelve releases of the program were made as part of the SAORD software suite between 1995 and 2000, when it was replaced by its successor, DS9.

The SAORD 1.9.1 source code tar files for all platforms (saord-1.9.1.tar.[gz,Z]) are available here:

SAORD 1.9.1 binary distribution tar files (saord-1.9.1-[arch].tar.[gz,Z]) are available here:

Documentation for SAOtng and other SAORD software can be accessed on-line:

SAOtng was developed with support from NASA's Applied Information Systems Research Program.

On-line papers about SAOtng:

PostScript versions of papers about SAOtng: