[fitsbits] start of Public Comment Period on compressed FITS image and tables

[Mark Taylor]

Dick (or others),

On Thu, 9 Jul 2015, Dick Shaw wrote:

> On Thu, 25 Jun 2015 23:14:47 -0400
> >From: "Tom McGlynn (NASA/GSFC Code 660.1)" <tom.mcglynn at nasa.gov>
> > 
> > I've almost no insight into table compression.  Given that no one seems to
> > be using this convention, my suggestion would be that it's premature to add
> > to the standard.
> 
> These compression techniques are used extensively at NOAO and (I believe) at
> STScI, though not as the only way to package data for transport. I know of
> some popular applications and systems (e.g., DS9, IRAF) that treat
> FITS-compressed data transparently. I do not know the extent of its use
> elsewhere, but I suspect it will be used more widely once this capability is
> part of the Standard.

can you confirm that you know of extensive use of FITS compression
for *table*, as opposed to image, data?  Nobody else in this discussion
seems to have presented any evidence or examples of tile-compressed FITS
tables actually in use.  Given that, the set of arguments for adopting
the Tiled Table Compression part of the proposed text (sec 10.3)
would seem to be different than that for Tiled Image Compression
(sec 10.1), since it seems clear that tile-compressed FITS images 
are already in wide usage.  But if you can cite extensive use of
table compression as well, that's relevant information.

Mark

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/