JS9 brings our Desktop DS9 image display to your browser:

• display FITS images and tables in a Web page
• drag and drop FITS images and tables
• retrieve FITS files from data archives
• change the colormap and scale algorithm
• blend images and apply RGB image filters
• mouse move displays pixel values, WCS info
• one finger displays pixel values, WCS info
• mouse press/move changes the contrast/bias
• two fingers changes the contrast/bias
• create and manipulate regions of interest
• extend JS9 using plugins and the public API
• perform data analysis (local and server-side)
• control JS9 from a command shell or Python
• print images, save images, etc ...

Drag and drop a FITS astronomical data file onto the display and JS9 functionality immediately becomes available: zoom, pan, colormaps, scaling, regions ...

By extending JS9 with the plugin facility and the public API, you can perform browser-based analysis on the displayed image: click the Plugins tab, create a region, move it around ...

In addition, images loaded from a server support remote (server-side) analysis. For example, analysis can run when a region changes, with results displayed back in your browser: click the Analysis tab, choose a task, create a region, move it around ...

• JS9 User Manual
• Installing JS9
• Adding JS9 To a Web Page
• Adding Data To a Web page
• Local Analysis (Plugins) With JS9
• The JS9 Public API
• Adding Server-side (Back-end) Analysis
• Server-side Analysis With JS9
• Dealing with Large Files
• JS9 Regions Format
• External Messaging with JS9
• JS9 with Python and Jupyter
• JS9 Site Preferences
• ChangeLog
• Known Issues

• JS9 Demo: the basics
• JS9 Demo: web page control of JS9
• JS9 Demo: setting the size of the JS9 display
• JS9 Demo: adding plugins to JS9
• JS9 Demo: the imexam plugin for JS9
• JS9 Demo: image blending
• JS9 Demo: overlaying catalogs
• JS9 Demo: pan and zoom
• JS9 Demo: RGB composite images
• JS9 Demo: independent instances of JS9
• JS9 Demo: server-side data analysis
• JS9 Demo: running tasks when a region changes
• JS9 Demo: creating a JS9 instance dynamically
• JS9 Demo: preloading images into JS9
• JS9 Demo: displaying different FITS datatypes
• JS9 Demo: PNG representation files vs FITS files

Release 1.8 (03/21/16) adds support for image blending, image filters, wcs reprojections, colorbar, blinking, gaussian blur, line region with distance measure, raw data layer manipulation.

Release 1.7 (01/12/16) adds support for resizing the display, adding tooltips to catalogs, and embedding JS9 in Jupyter/IPython.

Release 1.6 (11/7/15) adds support for loading FITS URLs via proxy, dealing with large files, and iOS improvements.

Release 1.5 (7/9/15) adds support for importing DS9/Funtools regions, and for running the back-end helper using https.

Release 1.4 (5/3/15) provides bug fixes for the binning plugin, adds a user preference plugin, and supports export to FITS and PNG files.

Release 1.3 (3/30/15) incorporates the standard cfitsio FITS library, using Emscripten to compile to JavaScript.

Release 1.2 (1/4/15) adds support for the new pyjs9 Python interface via GET/POST support in the back-end Node.js server.

JS9 runs on Web browsers that support the HTML5 canvas element, including all recent versions of FireFox, Chrome, Safari, and IE.

JS9 is distributed under the terms of The MIT License.

Contact: Eric Mandel, Harvard-Smithsonian Center for Astrophysics

The current JS9 source tar file is available below. This will allow you to display FITS images (drag-and-drop and URL-based access) with all essential functionality, including browser-based plugins.

The pyjs9 Python interface supports the JS9 Public API and a short-cut command interface, communicating with JS9 through the back-end Node helper.

To run the demo pages at your site, download the data tar file.

To configure a back-end Node helper (for server-side analysis and external control), you also will need to install the cfitsio library or the funtools package.

Tar files:

• js9 v1.8
• pyjs9 v1.0
• js9 data
• funtools

JS9 and pyjs9 also are available on GitHub, where the repositories contain the very latest bug fixes and enhancements:

• js9
• pyjs9
• js9 data
• funtools

JS9 is powered by the following technologies, to whom grateful acknowledgment is made:

• HTML5 for image display and most everything
• jquery for programming ease (http://jquery.com/)
• fabric.js for 2D graphics (http://fabricjs.com/)
• emscripten for C-to-JavaScript ( http://emscripten.org)
• dynamic drive for light windows (http://www.dynamicdrive.com)
• flot for plotting (http://www.flotcharts.org/)
• medialize for jquery.contextMenu (http://medialize.github.io/jQuery-contextMenu/)
• arrive.js for MutationObserver support (https://github.com/uzairfarooq/arrive)
• appcropolis for double click support (http://appcropolis.com/blog/howto/implementing-doubletap-on-iphones-and-ipads/)
• spin.js for spinner support (http://spin.js.org/)
• Marc J Schmidt for CSS element queries (https://github.com/marcj/css-element-queries)
• HEASARC for CFITSIO lib (http://heasarc.gsfc.nasa.gov/fitsio/)
• IPAC for Montage (http://montage.ipac.caltech.edu/)
• SAO/TDC for WCS lib (http://tdc-www.harvard.edu/wcstools/)

Thanks for important suggestions and (sometimes) code from:

• Joseph DePasquale, CfA (image blending techniques)
• Kathy Lestition, CfA (education and outreach)
• Briehan Lombaard SAAO (telescope control)
• John Roll, Facebook (fitsy, data analysis plugins)
• Frank Sienkiewicz, CfA (education and outreach)
• Pat Slane, CfA (the needs of research vs. education)

JS9 development at the Harvard-Smithsonian Center for Astrophysics is supported by Smithsonian Institution and the Chandra X-ray Science Center.