[GRASS5] 5.7: make GRASS_INT_ZLIB default?

Glynn Clements glynn at gclements.plus.com
Mon Nov 22 14:20:05 EST 2004


Markus Neteler wrote:

> > > proposal for 5.7-CVS: make zlib compression instead of RLE the
> > > default setting, probably modifying:
> > > 
> > > grass57/lib/gis > grep GRASS_INT_ZLIB *
> > > opencell.c:     COMPRESSION_TYPE = getenv("GRASS_INT_ZLIB") ? 2 : 1;
> > > 
> > > Are there objections?
> > 
> > The most obvious problem is that raster maps will be unreadable on
> > versions of GRASS which pre-date the addition of zlib support.
> 
> Isn't it possible then to 
>  r.compress -u
> in the ZLIB-GRASS version and then read it with the older GRASS?

Yes.

> The change is similar to the LZW change some years ago (which went smoothly).

The main issue is that people need to be aware of the change, and to
remember it at relevant times.

[Aside: When I had to deal with Windows users on a regular basis, I
would regularly end up downloading a 1Mb+ email over a 28.8k link only
to find that it contained an MS-Word 8 document. The sender knew that
I could only read version <= 7 documents; they just didn't remember at
the right time.]

-- 
Glynn Clements <glynn at gclements.plus.com>




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