AVM with Javascript

I've mentioned Astronomy Visualization Metadata before as well as my attempts to make a microformat and include the object categories in LookUP results. It is an attempt to add useful astronomical information to astronomical image files ("pretty pictures") used on the web so that when someone downloads an astronomical image the information such as position, object name, observing frequencies etc go with it (unless it gets edited).

Recently, I've been thinking about the possibility of placing pretty pictures in Chromoscope. This is already possible in the WorldWideTelescope plug-in but getting it to work in a normal browser requires a bit of effort. The idea isn't fully fledged yet but, to make it even tennable, I had to be able to extract the metadata from the image within the web-browser.

A few weeks ago I discovered a nice Javascript library that reads EXIF information from images. This was a good start but I soon discovered that it didn't read the AVM data as it isn't stored in the same way as the EXIF information. After a bit of head scratching, and reading the Adobe XMP specifications, I was able to adapt the EXIF Javascript library to read AVM data too. I've created a test page with a few images on it to check that it works. Thanks to @kimberlykowal for helping check the Chandra image.

Posted in astro blog by Stuart on Tuesday 24th Aug 2010 (19:28 BST) | Permalink
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