[fitsmime] FITS Mime-Types for Mosaics

[Steve Allen]

On Fri 2002-12-06T11:12:15 -0500, William Joye hath writ:

> image/fits-mosaic
>
> this would fit in well with the existing proposed mime-types... comments?

Being a producer of FITS files from a mosaic detector, I agree
wholeheartedly that there should be such a MIME type.  In the same
breath, however, I have to point out that there are no official
conventions and, indeed, no unofficial conventions which describe the
properties of a mosaic file.

Bill and I are intimately familiar with this.  We have been
collaborating informally for several years to ensure that ds9 can
consume mosaic files both from NOAO (which has the first CCD mosaic
with widely-distributed files, and which is understood by IRAF)
and from my own code for the DEIMOS mosaic (which conforms with
NOAO only to the extent required by ds9, but aspires to use an
entirely different mechanism for describing the mosaic layout
that is based on the WCS papers).


After rewriting 29 drafts of the RFC I have come to the opinion
that, within the scope of FITS convention and agreement, there
are only two kinds of FITS files, and therefore can only be
two MIME types:

application/fits
    This would be the default MIME type for FITS files which are not
    classified by their creator.

image/fits
    This would be the MIME type for FITS files whose creator is
    willing to assert that they are principally intended to
    communicate the content of the image in the PHDU.

Any other MIME types would require more conventions and agreements
within the FITS community.  I believe that more such conventions and
agreements would be a good thing.  I also believe that they will not
happen anytime soon, and that the need for these two basic MIME types
for FITS is great enough to proceed now.

I am not convinced that the scope of this discussion should stray into
the field of getting more conventions and agreements from the FITS
community, but that depends on the urgency of the timescale to
produce the (first) RFC.

--
Steve Allen          UCO/Lick Observatory       Santa Cruz, CA 95064
sla at ucolick.org      Voice: +1 831 459 3046     http://www.ucolick.org/~sla
PGP: 1024/E46978C5   F6 78 D1 10 62 94 8F 2E    49 89 0E FE 26 B4 14 93