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

[Dick Shaw]

Hi Mark,

Sorry, I was speaking of image compression in that snippet. I'm not aware of the extent that tiled 
table compression has been taken up. I think it was Tom who suggested that table compression may 
be more relevant if/when folks start storing images in table variable length arrays.

Sorry for the confusion.

Regards,
Dick

On Mon, 13 Jul 2015 14:57:16 +0100 (BST)
  Mark Taylor <M.B.Taylor at bristol.ac.uk> wrote:
> 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/