[fitswcs] VO standard for JPEG with WCS

[William Pence]

FYI, there was a brief email exchange on the VO email lists 
(apps at ivoa.net and dal at ivao.net) concerning encoding WCS information in 
JPEG images.  Copies of the current thread of 3 messages are shown 
below.  If you are interested in this topic, you can subscribe to the 
email lists at http://www.ivoa.net/forum/

Bill Pence

Pierre Fernique wrote:
> 
> 
> Hi all,
> 
> Some projects are using JPEG images with WCS keywords or FITS header 
> memorized into a JPEG comment segment (DSS colour images from MAST, SDSS 
> JPEG images, Aladin JPEG images,...).
> 
> Unfortunately these methods are not compatible, not documented and seems 
> to evolve.
> 
> Could we have a kind of VO standard related to this point ?
> 
> One suggestion would be to put the FITS header - or a portion of the 
> FITS header - into a JPEG comment segment (starting with FF FE) directly 
> in ASCII but with the possibility for wrapping each line by a CR instead 
> of keeping the 80 character FITS justification. By this way, a simple 
> "strings" command (or equivalent) allows to display immediately the 
> metadata. Another advantage, and not the least, is to have the 
> possibility for keeping all the FITS metadata.
> 
> Good idea ? Bad idea ? Other suggestions ?
> 
> Regards
> Pierre Fernique

Arnold Rots wrote:
> Since it can be specified in STC XML, one could include an STC
> ObsDataLocation element. That way we use a VO standard.
> 
>   - Arnold
> 
> --------------------------------------------------------------------------
> Arnold H. Rots                                Chandra X-ray Science Center
> Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
> 60 Garden Street, MS 67                              fax:  +1 617 495 7356
> Cambridge, MA 02138                             arots at head.cfa.harvard.edu
> USA                                     http://hea-www.harvard.edu/~arots/
> --------------------------------------------------------------------------

Ray Plante wrote:
> Hey Pierre,
> 
> A standard for tagging JPEGs with metadata for outreach purposes is in 
> the works, driven by a US-European collaboration.  It's current form is 
> in the IVOA is a Note, "Astronomical Outreach Imagery Metadata Tags for 
> the Virtual Observatory" 
> (http://www.ivoa.net/Documents/latest/AOIMetadata.html).
> The contact people in Europe are Lars Lindberg Christensen and Markus 
> Dolensky, and in the US, Robert Hurt.  They are in the process of 
> revising the document and getting ready for a comment process for both 
> the outreach community and the IVOA.
> 
> cheers,
> Ray

-- 
____________________________________________________________________
Dr. William Pence                       William.Pence at nasa.gov
NASA/GSFC Code 662       HEASARC        +1-301-286-4599 (voice)
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