#2349: CELL raster format: make ZLIB level 3 standard compression instead of RLE -------------------------+-------------------------------------------------- Reporter: neteler | Owner: grass-dev@… Type: enhancement | Status: new Priority: critical | Milestone: 7.0.0 Component: Raster | Version: svn-releasebranch70 Keywords: | Platform: All Cpu: Unspecified | -------------------------+--------------------------------------------------
Comment(by glynn): Replying to [ticket:2349 neteler]: > At time, integer maps (CELL) are still compressed with RLE > This leads to a huge waste of disk space when it comes to large > data. > > Proposal: make ZLIB, level 3 the standard compression. Is GRASS_INT_ZLIB support now old enough that it can be taken for granted? > At time we can enable the environment variable GRASS_INT_ZLIB > but it will use the default ZLIB level 6 compression which > is too CPU intensive. So a (user) control over this is important. The current behaviour is that setting GRASS_INT_ZLIB to anything (even an empty string) will enable zlib compression at the hard-coded level. One option is to parse the value as an integer and use the result as the compression level. However, it's possible that people are currently using e.g. GRASS_INT_ZLIB=1 to enable it with the existing default level. Another option is to add another environment variable for the level. Aside: if there are still systems out there using the historical limit of 4096 bytes of memory for the combination of environment variables and arguments (argv), we might want to think about making GRASS less greedy with respect to environment variables. -- Ticket URL: <http://trac.osgeo.org/grass/ticket/2349#comment:2> GRASS GIS <http://grass.osgeo.org> _______________________________________________ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev