[GRASS-dev] [GRASS GIS] #3119: r.out., gdal -c should not write Metadata: COLOR_TABLE_RULE_RGB

[GRASS GIS]

#3119: r.out.,gdal -c  should not write Metadata: COLOR_TABLE_RULE_RGB
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  Reporter:  neteler      |      Owner:  grass-dev@…
      Type:  defect       |     Status:  new
  Priority:  normal       |  Milestone:  7.2.0
 Component:  Raster       |    Version:  svn-trunk
Resolution:               |   Keywords:  r.out.gdal
       CPU:  Unspecified  |   Platform:  Unspecified
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Comment (by mmetz):

 Replying to [comment:2 neteler]:
 > Thanks.
 >
 > Just an idea: should -c trigger -m automatically or is there any -c use
 case where the GRASS color rules are still wanted in the metadata?

 The main purpose of -c is to suppress those long color tables for UInt16
 in GTiff: one separate entry for each possible value which makes rendering
 very slow. GTiff color tables and GRASS color rules are not the same, e.g.
 a simple GRASS color rule such as

 {{{
 0 black
 255 white
 }}}

 is expanded to 256 entries for Byte. GRASS r.in.gdal prefers GRASS color
 rules as custom metadata over standard color tables, therefore these GRASS
 color rules are wanted also with the -m flag. BTW, earlier versions of
 QGIS also recognized these GRASS color rules. Format-dependent color
 tables as such are not custom metadata, the GDAL driver decides if the
 selected format supports color tables. Therefore I would regard the -c and
 -m flags as independent of each other.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3119#comment:3>
GRASS GIS <https://grass.osgeo.org>