[GRASS-dev] [GRASS GIS] #2349: CELL raster format: make ZLIB level 3 standard compression instead of RLE

[GRASS GIS]

#2349: CELL raster format: make ZLIB level 3 standard compression instead of RLE
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  Reporter:  neteler      |      Owner:  grass-dev@…
      Type:  enhancement  |     Status:  new
  Priority:  critical     |  Milestone:  7.1.0
 Component:  Raster       |    Version:  svn-trunk
Resolution:               |   Keywords:  compression, r.compress, null
       CPU:  Unspecified  |   Platform:  All
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Comment (by glynn):

 Replying to [comment:26 neteler]:

 > Would r.compress -u followed by r.compress do the job? From a user's
 point this might be the best solution.

 It would probably work. A better (but still simple) option would be to add
 a flag to r.compress so that it will process an already-compressed map
 (rather than assuming it doesn't need to do anything).

 Ultimately we need something which will just update the null file,
 probably an enhancement to r.null.

 Note that, at present, "r.null -c" or "r.support -n" will generate a
 broken map if GRASS_COMPRESS_NULLS is set, as they will write compressed
 data to the null2 file but won't write the row pointers.

 Actually, those modules are already on shaky ground because they're
 passing an invalid map index as the "fd" parameter to
 Rast!__write_null_bits().

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2349#comment:27>
GRASS GIS <http://grass.osgeo.org>