I have a bunch of JPEG, JPEG2000 GIF and PNG files that in theory could be used for some types of science analysis if there were temporal and spatial information in them.
Years ago, I had looked into trying to put some of the information as EXIF into the files, and I could enter timing information (DateTimeOriginal, SubsecTimeOriginal, ExposureTime), and even location of the main object of interest (SubjectArea), but it had some issues with distance to the object (SubjectDistance), as it stored it as a rational number (LONG/LONG), in meters, and so the farthest distance I could specify was about 0.014 AU.
Is anyone else aware of people embedding scientific metadata in common-use graphical formats?
And if so, can you point me towards the specification, project, or implementation?
(and other than GeoTIFF or the like ... we just don't use TIFF except for sending to museums; I'm interested in trying to put the critical metadata into the browse images that we're generating for the scientists)
Answer
After a bit of research, I believe the most robust solution that I could find is the 'Astronomy Visualization Metadata (AVM) standard for astronomical imagery', which uses Adobe's XMP standard to embed the metadata as RDF. XMP can be embedded in PDF, JPEG, JPEG 2000, GIF, PNG, TIFF, PS, EPS and audio and other non-image formats.
Other potential candidates are the 2006 IVOA note, 'Astronomical Outreach Imagery Metadata Tags for the Virtual Observatory, which covers how to insert metadata into JPEG images for use in outreach (museums, etc.), or to insert STC-X (the XML serialization of the Space Time Coordinate Metadata) in the JPEG headers, as referenced in 2008 on an IVOA mailing list.
update : In re-reading the AVM webpage, it seems that OIM is a precursor to AVM :
Previous AVM Versions
The IVOA note for Version 1.0 September 2006 (Retired December 2007, previously called Astronomical Outreach Metadata):
As such, I see little reason to leave that one as an option, as I'd assume it to be deprecated. (I've striken it from the earlier text)
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