|
|
@@ -279,12 +279,16 @@ The GRASS GIS raster format is architecture independent and portable between
|
|
|
<h3>Raster compression</h3>
|
|
|
<!-- keep in sync with raster/r.compress/r.compress.html -->
|
|
|
|
|
|
-
|
|
|
All GRASS GIS raster map types are by default ZLIB compressed, i.e. using
|
|
|
ZLIB's deflate algorithm. Through the environment variable
|
|
|
<tt>GRASS_COMPRESSOR</tt> the compression method can be set to RLE, ZLIB,
|
|
|
LZ4, or BZIP2.
|
|
|
<p>
|
|
|
+Important: the NULL file compression must be explicitly turned on with
|
|
|
+<tt>export GRASS_COMPRESS_NULLS=1</tt> - such raster maps can then only
|
|
|
+be opened with GRASS GIS 7.2.0 or later. NULL file compression can be
|
|
|
+managed with <b>r.null -z</b>.
|
|
|
+<p>
|
|
|
Integer (CELL type) raster maps can be compressed with RLE if
|
|
|
the environment variable <tt>GRASS_INT_ZLIB</tt> exists and is set to value
|
|
|
0. However, this is not recommended.
|
Markus Neteler