gzipped images in SIAP 1.0

[Mark Taylor]

On Tue, 22 May 2007, Rob Seaman wrote:

> On May 22, 2007, at 11:50 AM, Steve Allen wrote:
>
>>> A tile compressed file is a legal FITS bintable.
>> 
>> Unfortunately in the purely FITS world "legal" has no mechanism for 
>> proceeding to "comprehensible".
>
> The mechanism is the same as for the VO world:  interoperable prototypes. 
> Any application layered on CFITSIO already supports FITS tile compression 
> transparently.  In that case, calling it an image/fits would be perfectly 
> correct.

RFC4047 says:

    A FITS file described with the media type "image/fits" SHOULD be
    principally intended to communicate the single data array in the
    PHDU.

as I understand it tile-compressed FITS images are stored in a BINTABLE
extension (hence not the PHDU), so they should properly be described
as application/fits and not image/fits.

-- 
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/